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Lucidi M, Visaggio D, Migliaccio A, Capecchi G, Visca P, Imperi F, Zarrilli R. Pathogenicity and virulence of Acinetobacter baumannii: Factors contributing to the fitness in healthcare settings and the infected host. Virulence 2024; 15:2289769. [PMID: 38054753 PMCID: PMC10732645 DOI: 10.1080/21505594.2023.2289769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 11/27/2023] [Indexed: 12/07/2023] Open
Abstract
Acinetobacter baumannii is a common cause of healthcare-associated infections and hospital outbreaks, particularly in intensive care units. Much of the success of A. baumannii relies on its genomic plasticity, which allows rapid adaptation to adversity and stress. The capacity to acquire novel antibiotic resistance determinants and the tolerance to stresses encountered in the hospital environment promote A. baumannii spread among patients and long-term contamination of the healthcare setting. This review explores virulence factors and physiological traits contributing to A. baumannii infection and adaptation to the hospital environment. Several cell-associated and secreted virulence factors involved in A. baumannii biofilm formation, cell adhesion, invasion, and persistence in the host, as well as resistance to xeric stress imposed by the healthcare settings, are illustrated to give reasons for the success of A. baumannii as a hospital pathogen.
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Affiliation(s)
- Massimiliano Lucidi
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
| | - Daniela Visaggio
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | | | | | - Paolo Visca
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | - Francesco Imperi
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | - Raffaele Zarrilli
- Department of Public Health, University of Naples Federico II, Naples, Italy
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Kharat AS, Makwana N, Nasser M, Gayen S, Yadav B, Kumar D, Veeraraghavan B, Mercier C. Dramatic increase in antimicrobial resistance in ESKAPE clinical isolates over the 2010-2020 decade in India. Int J Antimicrob Agents 2024; 63:107125. [PMID: 38431109 DOI: 10.1016/j.ijantimicag.2024.107125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 02/07/2024] [Accepted: 02/21/2024] [Indexed: 03/05/2024]
Abstract
RATIONALE AND OBJECTIVES ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) constitute a threat to humans worldwide. India is now the most populous country. The goal was to investigate the evolution of the rates of antimicrobial resistance in ESKAPE pathogens across India over the 2010-20 decade. METHODS The data (89 studies) were retrieved from the Medline PubMed repository using specific keywords. RESULTS The study of 20 177 ESKAPE isolates showed that A. baumannii isolates were the most represented (35.9%, n = 7238), followed by P. aeruginosa (25.3%, n = 5113), K. pneumoniae (19.5%, n = 3934), S. aureus (16.3%, n = 3286), E. faecium (2.6%, n = 517) and Enterobacter spp. (0.4%, n = 89). A notable increase in the resistance rates to antimicrobial agents occurred over the 2010-20 decade. The most important levels of resistance were observed in 2016-20 for A. baumannii (90% of resistance to the amoxicillin-clavulanate combination) and K. pneumoniae (81.6% of resistance to gentamycin). The rise in β-lactamase activities was correlated with an increase in the positivity of Gram-negative isolates for β-lactamase genes. CONCLUSIONS This review highlighted that, in contrast to developed countries that kept resistance levels under control, a considerable increase in resistance to various classes of antibiotics occurred in ESKAPE pathogens in India over the 2010-2020 decade.
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Affiliation(s)
- Arun S Kharat
- Laboratory of Applied Microbiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
| | - Nilesh Makwana
- Laboratory of Applied Microbiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Mahfouz Nasser
- Department of Biotechnology, Dr. Babasaheb Ambedkar Marathwada University, Subcampus Osmanbad, MS, Aurangabad, Maharashtra, India; National Center for Public Health Laboratories, Hodeidah, Yemen
| | - Samarpita Gayen
- Department of Biotechnology, Dr. Babasaheb Ambedkar Marathwada University, Subcampus Osmanbad, MS, Aurangabad, Maharashtra, India
| | - Bipin Yadav
- Laboratory of Applied Microbiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Durgesh Kumar
- Laboratory of Applied Microbiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Balaji Veeraraghavan
- Department of Clinical Microbiology, Christian Medical College, Vellore Tamil Nadu, India
| | - Corinne Mercier
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France.
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Liu X, Qin P, Wen H, Wang W, Zhao J. Seasonal meropenem resistance in Acinetobacter baumannii and influence of temperature-driven adaptation. BMC Microbiol 2024; 24:149. [PMID: 38678219 PMCID: PMC11055336 DOI: 10.1186/s12866-024-03271-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 03/22/2024] [Indexed: 04/29/2024] Open
Abstract
BACKGROUND Recognition of seasonal trends in bacterial infection and drug resistance rates may enhance diagnosis, direct therapeutic strategies, and inform preventive measures. Limited data exist on the seasonal variability of Acinetobacter baumannii. We investigated the seasonality of A. baumannii, the correlation between temperature and meropenem resistance, and the impact of temperature on this bacterium. RESULTS Meropenem resistance rates increased with lower temperatures, peaking in winter/colder months. Nonresistant strain detection exhibited temperature-dependent seasonality, rising in summer/warmer months and declining in winter/colder months. In contrast, resistant strains showed no seasonality. Variations in meropenem-resistant and nonresistant bacterial resilience to temperature changes were observed. Nonresistant strains displayed growth advantages at temperatures ≥ 25 °C, whereas meropenem-resistant A. baumannii with β-lactamase OXA-23 exhibited greater resistance to low-temperature (4 °C) stress. Furthermore, at 4 °C, A. baumannii upregulated carbapenem resistance-related genes (adeJ, oxa-51, and oxa-23) and increased meropenem stress tolerance. CONCLUSIONS Meropenem resistance rates in A. baumannii display seasonality and are negatively correlated with local temperature, with rates peaking in winter, possibly linked to the differential adaptation of resistant and nonresistant isolates to temperature fluctuations. Furthermore, due to significant resistance rate variations between quarters, compiling monthly or quarterly reports might enhance comprehension of antibiotic resistance trends. Consequently, this could assist in formulating strategies to control and prevent resistance within healthcare facilities.
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Affiliation(s)
- Xiaoxuan Liu
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China
| | - Pu Qin
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China
| | - Hainan Wen
- Department of Laboratory Medicine, Affiliated Hospital of Chengde Medical University, Chengde, 067000, People's Republic of China
| | - Weigang Wang
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China
| | - Jianhong Zhao
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China.
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Sotomayor N, Villacis JE, Burneo N, Reyes J, Zapata S, Bayas-Rea RDLÁ. Carbapenemase genes in clinical and environmental isolates of Acinetobacter spp. from Quito, Ecuador. PeerJ 2024; 12:e17199. [PMID: 38680892 PMCID: PMC11056107 DOI: 10.7717/peerj.17199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 03/14/2024] [Indexed: 05/01/2024] Open
Abstract
Carbapenem-resistant Acinetobacter spp. is associated with nosocomial infections in intensive care unit patients, resulting in high mortality. Although Acinetobacter spp. represent a serious public health problem worldwide, there are a few studies related to the presence of carbapenemases in health care facilities and other environmental settings in Ecuador. The main aim of this study was to characterize the carbapenem-resistant Acinetobacter spp. isolates obtained from four hospitals (52) and from five rivers (27) close to Quito. We used the disc diffusion and EDTA sinergy tests to determine the antimicrobial susceptibility and the production of metallo β-lactamases, respectively. We carried out a multiplex PCR of gyrB gene and the sequencing of partial rpoB gene to bacterial species identification. We performed molecular screening of nine carbapenem-resistant genes (blaSPM, blaSIM, blaGIM, blaGES, blaOXA-23, blaOXA-24, blaOXA-51, blaOXA-58, and blaOXA-143) by multiplex PCR, followed by identification using sequencing of blaOXA genes. Our findings showed that carbapenem-resistant A. baumannii were the main species found in health care facilities and rivers. Most of the clinical isolates came from respiratory tract samples and harbored blaOXA-23, blaOXA-366, blaOXA-72, blaOXA-65, blaOXA-70, and blaOXA-143-like genes. The river isolates harbored only the blaOXA-51 and probably blaOXA-259 genes. We concluded that the most predominant type of carbapenem genes among isolates were both blaOXA-23 and blaOXA-65 among A. baumannii clinical isolates.
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Affiliation(s)
- Nicole Sotomayor
- Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - José Eduardo Villacis
- Centro de Referencia Nacional de Resistencia a los Antimicrobianos, Instituto Nacional de Investigación en Salud Pública-INSPI Dr. Leopoldo Izquieta Pérez, Quito, Ecuador
- Centro de Investigación para la Salud en América Latina (CISeAL), Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Noela Burneo
- Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Jorge Reyes
- Facultad de Ciencias Químicas, Universidad Central del Ecuador, Quito, Ecuador
| | - Sonia Zapata
- Instituto de Microbiología, Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
| | - Rosa de los Ángeles Bayas-Rea
- Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
- Instituto de Microbiología, Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
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Dos Santos LA, Cayô R, Valiatti TB, Gales AC, de Araújo LFB, Rodrigues FM, de Carvalho TS, Vaz MAB, Campanharo M. Biodiversity of carbapenem-resistant bacteria in clinical samples from the Southwest Amazon region (Rondônia/Brazil). Sci Rep 2024; 14:9383. [PMID: 38654061 DOI: 10.1038/s41598-024-59733-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/15/2024] [Indexed: 04/25/2024] Open
Abstract
Brazil is recognized for its biodiversity and the genetic variability of its organisms. This genetic variability becomes even more valuable when it is properly documented and accessible. Understanding bacterial diversity through molecular characterization is necessary as it can improve patient treatment, reduce the length of hospital stays and the selection of resistant bacteria, and generate data for health and epidemiological surveillance. In this sense, in this study, we aimed to understand the biodiversity and molecular epidemiology of carbapenem-resistant bacteria in clinical samples recovered in the state of Rondônia, located in the Southwest Amazon region. Retrospective data from the Central Public Health Laboratories (LACEN/RO) between 2018 and 2021 were analysed using the Laboratory Environment Manager Platform (GAL). Seventy-two species with carbapenem resistance profiles were identified, of which 25 species carried at least one gene encoding carbapenemases of classes A (blaKPC-like), B (blaNDM-like, blaSPM-like or blaVIM-like) and D (blaOXA-23-like, blaOXA-24-like, blaOXA-48-like, blaOXA-58-like or blaOXA-143-like), among which we will highlight Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Serratia marcescens, and Providencia spp. With these results, we hope to contribute to the field by providing epidemiological molecular data for state surveillance on bacterial resistance and assisting in public policy decision-making.
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Affiliation(s)
- Levy Assis Dos Santos
- Federal University of Rondônia Foundation (UNIR), Postgraduate Program in Conservation and Use of Natural Resources (PPGReN), Porto Velho, RO, Brazil.
- Central Public Health Laboratory of Rondônia (LACEN/RO), Medical Biology Center, Porto Velho, RO, Brazil.
| | - Rodrigo Cayô
- Laboratory ALERTA, Department of Medicine, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
- Laboratory of Bacteriology and Immunology (LIB), Department of Biological Sciences (DCB), Institute of Environmental, Chemical and Pharmaceutical Sciences (ICAQF), Federal University of São Paulo (UNIFESP), Diadema, SP, Brazil
| | - Tiago Barcelos Valiatti
- Laboratory ALERTA, Department of Medicine, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Ana Cristina Gales
- Laboratory ALERTA, Department of Medicine, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Larissa Fatarelli Bento de Araújo
- Federal University of Rondônia Foundation (UNIR), Postgraduate Program in Conservation and Use of Natural Resources (PPGReN), Porto Velho, RO, Brazil
| | - Fernando Marques Rodrigues
- Central Public Health Laboratory of Rondônia (LACEN/RO), Medical Biology Center, Porto Velho, RO, Brazil
| | - Tatiane Silva de Carvalho
- Central Public Health Laboratory of Rondônia (LACEN/RO), Medical Biology Center, Porto Velho, RO, Brazil
| | - Marcos André Braz Vaz
- Department of Informatics and Statistics, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil
| | - Marcela Campanharo
- Federal University of Rondônia Foundation (UNIR), Postgraduate Program in Conservation and Use of Natural Resources (PPGReN), Porto Velho, RO, Brazil
- Department of Agricultural and Biological Sciences (DCAB), Federal University of Espirito Santo, São Mateus, ES, Brazil
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Saikia S, Gogoi I, Oloo A, Sharma M, Puzari M, Chetia P. Co-production of metallo-β-lactamase and OXA-type β-lactamases in carbapenem-resistant Acinetobacter baumannii clinical isolates in North East India. World J Microbiol Biotechnol 2024; 40:167. [PMID: 38630176 DOI: 10.1007/s11274-024-03977-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 04/03/2024] [Indexed: 04/19/2024]
Abstract
Carbapenem-resistant Acinetobacter baumannii poses a significant threat to public health globally, especially due to its ability to produce multiple carbapenemases, leading to treatment challenges. This study aimed to investigate the antibiotic resistance pattern of carbapenem-resistant A. baumannii isolates collected from different clinical settings in North East India, focusing on their genotypic and phenotypic resistance profiles. A total of 172 multidrug-resistant A. baumannii isolates were collected and subjected to antibiotic susceptibility test using the Kirby-Bauer disk diffusion method. Various phenotypic tests were performed to detect extended-spectrum β-lactamase (ESBL), metallo-β-lactamase (MBL), class C AmpC β-lactamase (AmpC), and carbapenem hydrolyzing class D β-lactamase (CHDL) production among the isolates. Overexpression of carbapenemase and cephalosporinase genes was detected among the isolates through both phenotypic and genotypic investigation. The antibiotic resistance profile of the isolates revealed that all were multidrug-resistant; 25% were extensively drug-resistant, 9.30% were pan-drug-resistant, whereas 91.27% were resistant to carbapenems. In the genotypic investigation, 80.81% of isolates were reported harbouring at least one metallo-β-lactamase encoding gene, with blaNDM being the most prevalent at 70.34%, followed by blaIMP at 51.16% of isolates. Regarding class D carbapenemases, blaOXA-51 and blaOXA-23 genes were detected in all the tested isolates, while blaOXA-24, blaOXA-48, and blaOXA-58 were found in 15.11%, 6.97%, and 1.74% isolates respectively. Further analysis showed that 31.97% of isolates co-harboured ESBL, MBL, AmpC, and CHDL genes, while 31.39% of isolates co-harboured ESBL, MBL, and CHDL genes with or without ISAba1 leading to extensively drug-resistant or pan drug-resistant phenotypes. This study highlights the complex genetic profile and antimicrobial-resistant pattern of the isolates circulating in North East India, emphasizing the urgent need for effective infection control measures and the development of alternative treatment strategies to combat these challenging pathogens.
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Affiliation(s)
- Shyamalima Saikia
- Molecular Plant Taxonomy and Bioinformatics Research Laboratory, Department of Life Sciences, Dibrugarh University, Dibrugarh, Assam, 786004, India
| | - Indrani Gogoi
- Molecular Plant Taxonomy and Bioinformatics Research Laboratory, Department of Life Sciences, Dibrugarh University, Dibrugarh, Assam, 786004, India
| | - Amos Oloo
- Molecular Plant Taxonomy and Bioinformatics Research Laboratory, Department of Life Sciences, Dibrugarh University, Dibrugarh, Assam, 786004, India
| | - Mohan Sharma
- Integrated Molecular Diagnostic and Research Laboratory (BSL-2), District Hospital Tuensang, Tuensang, Nagaland, 798612, India
| | - Minakshi Puzari
- Molecular Plant Taxonomy and Bioinformatics Research Laboratory, Department of Life Sciences, Dibrugarh University, Dibrugarh, Assam, 786004, India
| | - Pankaj Chetia
- Molecular Plant Taxonomy and Bioinformatics Research Laboratory, Department of Life Sciences, Dibrugarh University, Dibrugarh, Assam, 786004, India.
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Li YY, Liu HC, Wang HP, DU TY, Jiang L. [Characteristics of drug resistance and biofilm formation in carbapenem-resistant Acinetobacter baumannii in hospitalized children]. Zhongguo Dang Dai Er Ke Za Zhi 2024; 26:358-364. [PMID: 38660899 DOI: 10.7499/j.issn.1008-8830.2309058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
OBJECTIVES To study the distribution, drug resistance, and biofilm characteristics of carbapenem-resistant Acinetobacter baumannii (CRAB) isolated from hospitalized children, providing a reference for the prevention and treatment of CRAB infections in hospitalized children. METHODS Forty-eight CRAB strains isolated from January 2019 to December 2022 were classified into epidemic and sporadic strains using repetitive extragenic palindromic sequence-based polymerase chain reaction. The drug resistance, biofilm phenotypes, and gene carriage of these two types of strains were compared. RESULTS Both the 22 epidemic strains and the 26 sporadic strains were producers of Class D carbapenemases or extended-spectrum β-lactamases with downregulated outer membrane porins, harboring the VIM, OXA-23, and OXA-51 genes. The biofilm formation capability of the sporadic strains was stronger than that of the epidemic strains (P<0.05). Genes related to biofilm formation, including Bap, bfs, OmpA, CsuE, and intI1, were detected in both epidemic and sporadic strains, with a higher detection rate of the intI1 gene in epidemic strains (P<0.05). CONCLUSIONS CRAB strains are colonized in the hospital, with sporadic strains having a stronger ability to form biofilms, suggesting the potential for forming new clonal transmissions in the hospital. Continuous monitoring of the epidemic trends of CRAB and early warning of the distribution of epidemic strains are necessary to reduce the risk of CRAB infections in hospitalized children.
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Affiliation(s)
- Yun-Yun Li
- Clinical Laboratory, Kunming Children's Hospital/Affiliated Children's Hospital of Kunming Medical University, Kunming 650100
| | | | - Hai-Ping Wang
- Clinical Laboratory, Kunming Children's Hospital/Affiliated Children's Hospital of Kunming Medical University, Kunming 650100
| | - Ting-Yi DU
- Clinical Laboratory, Kunming Children's Hospital/Affiliated Children's Hospital of Kunming Medical University, Kunming 650100
| | - Li Jiang
- Clinical Laboratory, Kunming Children's Hospital/Affiliated Children's Hospital of Kunming Medical University, Kunming 650100
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Correa A, Shehreen S, Machado LC, Thesier J, Cunic L, Petassi M, Chu J, Kapili B, Jia Y, England K, Peters J. Novel mechanisms of diversity generation in Acinetobacter baumannii resistance islands driven by Tn7-like elements. Nucleic Acids Res 2024; 52:3180-3198. [PMID: 38407477 PMCID: PMC11014353 DOI: 10.1093/nar/gkae129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 01/25/2024] [Accepted: 02/09/2024] [Indexed: 02/27/2024] Open
Abstract
Mobile genetic elements play an important role in the acquisition of antibiotic and biocide resistance, especially through the formation of resistance islands in bacterial chromosomes. We analyzed the contribution of Tn7-like transposons to island formation and diversification in the nosocomial pathogen Acinetobacter baumannii and identified four separate families that recognize different integration sites. One integration site is within the comM gene and coincides with the previously described Tn6022 elements suggested to account for the AbaR resistance island. We established Tn6022 in a heterologous E. coli host and confirmed basic features of transposition into the comM attachment site and the use of a novel transposition protein. By analyzing population features within Tn6022 elements we identified two potential novel transposon-encoded diversification mechanisms with this dynamic genetic island. The activities of these diversification features were confirmed in E. coli. One was a novel natural gain-of-activity allele that could function to broaden transposition targeting. The second was a transposon-encoded hybrid dif-like site that parasitizes the host dimer chromosome resolution system to function with its own tyrosine recombinase. This work establishes a highly active Tn7-like transposon that harnesses novel features allowing the spread and diversification of genetic islands in pathogenic bacteria.
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Affiliation(s)
- Alberto Correa
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | | | | | - Jordan Thesier
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | - Lille M Cunic
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | | | - Joshua Chu
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | | | - Yu Jia
- College of Life Sciences and Engineering Research Center of Bioreactor and Pharmaceutical Development (Ministry of Education), Jilin Agricultural University, Changchun City, Jilin Province, China
| | - Kevin A England
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY, USA
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Papadopoulou M, Deliolanis I, Polemis M, Vatopoulos A, Psichogiou M, Giakkoupi P. Characteristics of the Genetic Spread of Carbapenem-Resistant Acinetobacter baumannii in a Tertiary Greek Hospital. Genes (Basel) 2024; 15:458. [PMID: 38674392 PMCID: PMC11050095 DOI: 10.3390/genes15040458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 03/30/2024] [Accepted: 04/03/2024] [Indexed: 04/28/2024] Open
Abstract
Acinetobacter baumannii (Ab) has increasingly been identified as a cause of hospital-acquired infections and epidemics. The rise of carbapenem-resistant Acinetobacter baumannii (CRAB) poses significant challenges in treatment. Nosocomial outbreaks linked to CRAΒ A. baumannii strains have been reported worldwide, including in Greece. This study aimed to analyze the molecular epidemiology trends of multidrug-resistant A. baumannii isolates in a tertiary hospital in Athens, Greece. A total of 43 clinical isolates of extensively drug-resistant (XDRAB), pan-drug-resistant (PDRAB), and CRAB were collected from patients suffering from blood infection, hospitalized between 2016 and 2020 at the internal medicine clinics and the ICU. A.baumannii isolates underwent testing for Ambler class B and D carbapenemases and the detection of ISAba1, and were typed, initially, using pulsed-field gel electrophoresis, and, subsequently, using sequence-based typing and multiplex PCR to determine European Clone lineages. The blaOXA-23 gene accompanied by ISAba1 was prevalent in nearly all A. baumannii isolates, except for one carrying blaOXA-58. The intrinsic blaOXA-51-like gene was found in all isolates. No Ambler class B carbapenemases (VIM, NDM) were detected. Isolates were grouped into four PF-clusters and no one-cluster spread was documented, consistent with the absence of outbreak. The study indicated that XDR/PDR-CRAB isolates predominantly produce OXA-23 carbapenemase and belong to European Clone II. Further research is needed to understand the distribution of resistant bacteria and develop effective prevention and control strategies.
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Affiliation(s)
- Martha Papadopoulou
- Laboratory for the Surveillance of Infectious Diseases-LSID, Department of Public Health Policy, University of West Attica, 11521 Athens, Greece; (A.V.); (P.G.)
| | - Ioannis Deliolanis
- Department of Microbiology, Laiko General Hospital, 11527 Athens, Greece;
| | - Michalis Polemis
- Hellenic National Public Health Organization, 15123 Athens, Greece;
| | - Alkiviadis Vatopoulos
- Laboratory for the Surveillance of Infectious Diseases-LSID, Department of Public Health Policy, University of West Attica, 11521 Athens, Greece; (A.V.); (P.G.)
| | - Mina Psichogiou
- 1st Department of Internal Medicine, Laiko General Hospital, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Panagiota Giakkoupi
- Laboratory for the Surveillance of Infectious Diseases-LSID, Department of Public Health Policy, University of West Attica, 11521 Athens, Greece; (A.V.); (P.G.)
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Roy S, Morita D, Bhattacharya S, Dutta S, Basu S. Novel sequence type of carbapenem-resistant Acinetobacter pittii ST1451 with enhanced virulence isolated from septicaemic neonates in India. J Antimicrob Chemother 2024; 79:779-783. [PMID: 38334368 DOI: 10.1093/jac/dkae024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 01/04/2024] [Indexed: 02/10/2024] Open
Abstract
BACKGROUND The clinical relevance of Acinetobacter pittii is increasing, but reports of this organism causing neonatal sepsis are rare. OBJECTIVES To understand the mechanisms of resistance and virulence of A. pittii isolated from neonatal blood belonging to a novel sequence type. MATERIALS AND METHODS Antibiotic susceptibility, MLST, WGS, phylogenomic comparison with a global collection of carbapenemase-harbouring A. pittii were done. To study the pathogenic potential of novel A. pittii, in vitro and in vivo assays were carried out. RESULTS AND DISCUSSION Two novel multidrug-resistant A. pittii from neonatal blood belonging to a novel sequence type 1451 (ST1451) were isolated. WGS revealed that the isolates were almost similar (147 SNP distant) and harbouring two carbapenem resistance genes blaNDM-1 with upstream ISAba125 and downstream bleMBL along with blaOXA-58 with upstream ISAba3. Other resistance genes included blaADC-25, blaOXA-533, aph(3″)-Ib, aph(3')-VIa, aph(6)-Id, aac(3)-IId, mph(E), msr(E), sul2 and tet(39), different efflux pump genes and amino acid substitutions within GyrA (Ser81Leu) and ParC (Ser84Leu; Glu88Ala) were detected among the isolates. The study genomes were closely related to four strains belonging to ST119. The isolates showed biofilm production, serum resistance, growth under iron limiting condition, surface-associated motility and adherence to host cell. Isolates induced cytokine production in the host cell and showed mice mortality. DISCUSSION AND CONCLUSIONS This study is the first report of the presence of blaNDM-1 in A. pittii from India along with another carbapenemase blaOXA-58. Emergence of highly virulent, multidrug-resistant A. pittii with attributes similar to A. baumannii calls for surveillance to identify the novel strains and their pathogenic and resistance potential.
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Affiliation(s)
- Subhasree Roy
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Daichi Morita
- Department of Microbiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Sushmita Bhattacharya
- Division of Biochemistry, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shanta Dutta
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Sulagna Basu
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
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Findlay J, Bianco G, Boattini M, Nordmann P. In vivo development of cefiderocol resistance in carbapenem-resistant Acinetobacter baumannii associated with the downregulation of a TonB-dependent siderophore receptor, PiuA. J Antimicrob Chemother 2024; 79:928-930. [PMID: 38297993 PMCID: PMC10984935 DOI: 10.1093/jac/dkae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024] Open
Affiliation(s)
- Jacqueline Findlay
- Medical and Molecular Microbiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Gabriele Bianco
- Microbiology and Virology Unit, University Hospital Città della Salute e della Scienza di Torino, Turin, Italy
- Department of Public Health and Paediatrics, University of Torino, Turin, Italy
| | - Matteo Boattini
- Microbiology and Virology Unit, University Hospital Città della Salute e della Scienza di Torino, Turin, Italy
- Department of Public Health and Paediatrics, University of Torino, Turin, Italy
| | - Patrice Nordmann
- Medical and Molecular Microbiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
- Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), University of Fribourg, Fribourg, Switzerland
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12
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Chen PK, Lee YT, Liu CY, Thuy TTD, Anh K, Wu JJ, Liao CH, Huang YT, Chen YC, Kao CY. A 19-year longitudinal study to characterize carbapenem-nonsusceptible Acinetobacter isolated from patients with bloodstream infections and the contribution of conjugative plasmids to carbapenem resistance and virulence. J Microbiol Immunol Infect 2024; 57:288-299. [PMID: 38350841 DOI: 10.1016/j.jmii.2024.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 12/23/2023] [Accepted: 01/25/2024] [Indexed: 02/15/2024]
Abstract
BACKGROUND This study aimed to characterize carbapenem-nonsusceptible Acinetobacter (CNSA) isolated from patients with bacteremia from 1997 to 2015. METHODS A total of 173 CNSA (12.3%) was recovered from 1403 Acinetobacter isolates. The presence of selected β-lactamase genes in CNSA was determined by PCR amplification. The conjugation test was used to determine the transferability of metallo-β-lactamase (MBL)-carrying plasmids. Whole genome sequencing in combination with phenotypic assays was carried out to characterize MBL-plasmids. RESULTS In general, a trend of increasing numbers of CNSA was observed. Among the 173 CNSA, A. baumannii (54.9%) was the most common species, followed by A. nosocomialis (23.1%) and A. soli (12.1%). A total of 49 (28.3%) CNSA were extensively drug-resistant, and all were A. baumannii. The most common class D carbapenemase gene in 173 CNSA was blaOXA-24-like (32.4%), followed by ISAba1-blaOXA-51-like (20.8%), ISAba1-blaOXA-23 (20.2%), and IS1006/IS1008-blaOXA-58 (11.6%). MBL genes, blaVIM-11,blaIMP-1, and blaIMP-19 were detected in 9 (5.2%), 20 (11.6%), and 1 (0.6%) CNSA isolates, respectively. Transfer of MBL genes to AB218 and AN254 recipient cells was successful for 7 and 6 of the 30 MBL-plasmids, respectively. The seven AB218-derived transconjugants carrying MBL-plasmids produced less biofilm but showed higher virulence to larvae than recipient AB218. CONCLUSIONS Our 19-year longitudinal study revealed a stable increase in CNSA during 2005-2015. blaOXA-24-like, ISAba1-blaOXA-51-like, and ISAba1-blaOXA-23 were the major determinants of Acinetobacter carbapenem resistance. MBL-carrying plasmids contribute not only to the carbapenem resistance but also to A. baumannii virulence.
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Affiliation(s)
- Pek Kee Chen
- Institute of Microbiology and Immunology, College of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Tzu Lee
- Department of Emergency Medicine, Taipei Veteran General Hospital, Taipei, Taiwan; School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chia-Ying Liu
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Tran Thi Dieu Thuy
- Institute of Microbiology and Immunology, College of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Kieu Anh
- Institute of Microbiology and Immunology, College of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Jiunn-Jong Wu
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung, Taiwan
| | - Chun-Hsing Liao
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Yu-Tsung Huang
- Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yu-Chen Chen
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Cheng-Yen Kao
- Institute of Microbiology and Immunology, College of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan; Health Innovation Center, National Yang Ming Chiao Tung University, Taiwan; Microbiota Research Center, National Yang Ming Chiao Tung University, Taiwan.
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Savin M, Sib E, Heinemann C, Eichel VM, Nurjadi D, Klose M, Andre Hammerl J, Binsker U, Mutters NT. Tracing clinically-relevant antimicrobial resistances in Acinetobacter baumannii-calcoaceticus complex across diverse environments: A study spanning clinical, livestock, and wastewater treatment settings. Environ Int 2024; 186:108603. [PMID: 38547543 DOI: 10.1016/j.envint.2024.108603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/13/2024] [Accepted: 03/23/2024] [Indexed: 04/26/2024]
Abstract
Acinetobacter baumannii has become a prominent nosocomial pathogen, primarily owing to its remarkable ability to rapidly acquire resistance to a wide range of antimicrobial agents and its ability to persist in diverse environments. However, there is a lack of data on the molecular epidemiology and its potential implications for public health of A. baumannii strains exhibiting clinically significant resistances that originate from non-clinical environments. Therefore, the genetic characteristics and resistance mechanisms of 80 A. baumannii-calcoaceticus (ABC) complex isolates, sourced from environments associated with poultry and pig production, municipal wastewater treatment plants (WWTPs), and clinical settings, were investigated. In total, our study classified 54 isolates into 29 previously described sequence types (STs), while 26 isolates exhibited as-yet-unassigned STs. We identified a broad range of A. baumannii STs originating from poultry and pig production environments (e.g., ST10, ST238, ST240, ST267, ST345, ST370, ST372, ST1112 according to Pasteur scheme). These STs have also been documented in clinical settings worldwide, highlighting their clinical significance. These findings also raise concerns about the potential zoonotic transmission of certain STs associated with livestock environments. Furthermore, we observed that clinical isolates exhibited the highest diversity of antimicrobial resistance genes (ARGs). In contrast to non-clinical isolates, clinical isolates typically carried a significantly higher number of ARGs, ranging from 10 to 15. They were also the exclusive carriers of biocide resistance genes and acquired carbapenemases (blaOXA-23, blaOXA-58, blaOXA-72, blaGIM-1, blaNDM-1). Additionally, we observed that clinical strains displayed an increased capacity for carrying plasmids and undergoing genetic transformation. This heightened capability could be linked to the intense selective pressures commonly found within clinical settings. Our study provides comprehensive insights into essential aspects of ABC isolates originating from livestock-associated environments and clinical settings. We explored their resistance mechanisms and potential implications for public health, providing valuable knowledge for addressing these critical issues.
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Affiliation(s)
- Mykhailo Savin
- Institute for Hygiene and Public Health, University Hospital Bonn, Bonn, Germany.
| | - Esther Sib
- Institute for Hygiene and Public Health, University Hospital Bonn, Bonn, Germany
| | | | - Vanessa M Eichel
- Section for Hospital Hygiene and Environmental Health, Center for Infectious Diseases, University Hospital Heidelberg, Heidelberg, Germany
| | - Dennis Nurjadi
- Department of Infectious Diseases and Microbiology, University of Lübeck and University Medical Center Schleswig-Holstein Campus Lübeck, Lübeck, Germany
| | - Marian Klose
- Institute for Hygiene and Public Health, University Hospital Bonn, Bonn, Germany
| | - Jens Andre Hammerl
- Department for Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Ulrike Binsker
- Department for Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Nico T Mutters
- Institute for Hygiene and Public Health, University Hospital Bonn, Bonn, Germany
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Uluçam Atay G, Bayramoğlu G, Tosun İ, Ünsal Ü. [Comparison of Three Different Methods in Investigating the Molecular Epidemiology of Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates]. MIKROBIYOL BUL 2024; 58:97-112. [PMID: 38676579 DOI: 10.5578/mb.202498131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2024]
Abstract
The aim of the study was to evaluate the relationship between carbapenem-resistant Acinetobacter baumannii isolates carrying oxacillinase-type carbapenemase genes with "international high-risk clones" (IC I, II, and III) by different molecular epidemiological methods and to statistically compare the concordance and discrimination power of the methods. Carbapenem-resistant and moderately susceptible A.baumannii isolates from non-repeating blood cultures of 72 patients were included in the study. The presence of "blaOXA-23 , blaOXA-24 , blaOXA-51 ve blaOXA-58 " genes within OXA-type carbapenemases was detected by polymerase chain reaction (PCR) method and confirmed by DNA sequence analysis. Pulsed f ield gel electrophoresis (PFGE), multilocus sequence typing (MLST) and matrix-assisted laser desorption/ ionization time- of-flight mass spectrometry (MALDI-TOF MS) analyses were performed to evaluate the clonal relations of IC I, II and III clones together with clinical isolates. In the statistical comparison of the methods, discrimination power was evaluated by Simpson index of diversity (SID) and concordance by "Wallace coefficient". All of the isolates were found to carry blaOXA-23 and blaOXA-51 genes. As a result of the bioinformatic analysis of the four isolates selected for sequence analysis; blaOXA-23 and blaOXA-51 genes were detected in the selected isolates, and the analysis of two isolates carrying blaOXA-51 gene showed 99% similarity with blaOXA-92 gene. The isolates were clustered into five pulsotypes (A, B, C, D and E) according to ≥ 85% similarity coefficient by PFGE. The isolates and RUH 875, RUH 134, LUH 5875 strains belonging to high-risk clones ICI, ICII and ICIII, respectively, were divided into five main groups [A (n= 58), B (n= 8), C (n= 4), D (n= 4) and E (n= 1)] and 10 subgroups (A1, A2, A4, A5, A6, A9, B1, B4, C3, D1) by PFGE. IC clone III (E1) and seven strains showed singleton PFGE profiles (A3, A7, A8, B2, B3, C1, C2). ICII was found in A5 subtype, ICI in C1 subtype and ICIII in E1 subtype. By PFGE subtype groups, 18 pulsotypes were determined and ST1, ST2, ST81, ST157 and ST604 sequence types were found in 20 isolates randomly selected from pulsotypes according to MLST Pasteur scheme (cpn60, fusA, gltA, pyrG, recA, rplB, rpoB). Principal component analysis (PCA) of the spectra of 72 A. baumannii isolates and ICI, ICII and ICIII clones was performed by MALDI-TOF MS. In PCA analysis, the cluster distance level was defined as 1.5 and the isolates were divided into three clusters. IC clone I, II and III together with 70 clinical isolates were grouped in one cluster, while two clinical isolates (AB083 and AB0115) formed singleton clusters. There was no significant agreement between MALDI-TOF MS; MLST and PFGE data according to Wallace coefficient. It was found that PFGE method gave significant results in terms of discrimination power with SID coefficient, MALDI-TOF MS PCA analysis had the lowest discrimination power value, and the Wallace coefficient result of PFGE and MLST was concordant. In conclusion, MALDI-TOF MS may not function as a gold standard method like PFGE and MLST for epidemiological analysis in A.baumannii species and the epidemiological typing protocols used for MALDI-TOF MS need to be improved and developed.
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Affiliation(s)
- Gülşen Uluçam Atay
- Recep Tayyip Erdoğan University, Vocational School of Health Services, Department of Medical Services and Techniques, Rize, Türkiye
| | - Gülçin Bayramoğlu
- Karadeniz Technical University Faculty of Medicine, Department of Medical Microbiology, Trabzon, Türkiye
| | - İlknur Tosun
- Karadeniz Technical University Faculty of Medicine, Department of Medical Microbiology, Trabzon, Türkiye
| | - Ülkü Ünsal
- Karadeniz Technical University Faculty of Health Sciences, Department of Health Management, Trabzon, Türkiye
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Naha A, Ramaiah S. Novel Antimicrobial Peptide SAAP Mutant as a Better Adjuvant to Sulbactam-Based Treatments Against Clinical Strains of XDR Acinetobacter baumannii. Probiotics Antimicrob Proteins 2024; 16:459-473. [PMID: 36971982 DOI: 10.1007/s12602-023-10067-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2023] [Indexed: 03/29/2023]
Abstract
The production of extended spectrum β-lactamases (ESBLs) in extensively drug-resistant (XDR) strains of Acinetobacter baumannii has created havoc amongst clinicians making the treatment procedure challenging. Carbapenem-resistant strains have displayed total ineffectiveness towards newer combinations of β-lactam-β-lactamase inhibitors (βL-βLI) in tertiary healthcare settings. Therefore, the present study was aimed to design potential β-lactamase antimicrobial peptide (AMP) inhibitors against ESBLs produced by the strains. We have constructed an AMP mutant library with higher antimicrobial efficacy (range: ~ 15 to 27%) than their parent peptides. The mutants were thoroughly screened based on different physicochemical and immunogenic properties revealing three peptides, namely SAAP-148, HFIAP-1, myticalin-C6 and their mutants with safe pharmacokinetics profile. Molecular docking highlighted SAAP-148_M15 displaying maximum inhibitory potential with lowest binding energies against NDM1 (- 1148.7 kcal/mol), followed by OXA23 (- 1032.5 kcal/mol) and OXA58 (- 925.3 kcal/mol). The intermolecular interaction profiles displayed SAAP-148_M15 exhibiting hydrogen bonds and van der Waals hydrophobic interactions with the crucial residues of metallo β-lactamase [IPR001279] and penicillin-binding transpeptidase [IPR001460] domains. Coarse-grained clustering and molecular dynamics simulations (MDS) further validated the stable backbone profile and minimal residue-level fluctuations of the protein-peptide complex that were maintained throughout the simulation timeframe. The present study hypothesised that the combination of sulbactam (βL) with SAAP-148_M15 (βLI) holds immense potential in inhibiting the ESBLs alongside restoration of sulbactam activity. The current in silico findings upon further experimental validations can pave path towards designing of successful therapeutic strategy against XDR strains of A. baumannii.
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Affiliation(s)
- Aniket Naha
- Medical and Biological Computing Laboratory, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Tamil Nadu, Vellore, 632014, India
- Department of Bio-Medical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Tamil Nadu, Vellore, 632014, India
| | - Sudha Ramaiah
- Medical and Biological Computing Laboratory, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Tamil Nadu, Vellore, 632014, India.
- Department of Bio-Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Tamil Nadu, Vellore, 632014, India.
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Moreira da Silva J, Menezes J, Fernandes L, Marques C, Costa SS, Timofte D, Amaral A, Pomba C. Dynamics of bla OXA-23 gene transmission in Acinetobacter spp. from contaminated veterinary environmental surfaces: an emerging One Health threat? J Hosp Infect 2024; 146:116-124. [PMID: 38365067 DOI: 10.1016/j.jhin.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/29/2024] [Accepted: 02/01/2024] [Indexed: 02/18/2024]
Abstract
BACKGROUND Carbapenem-resistant Acinetobacter baumannii is a common pathogen associated with healthcare-acquired infections, and robust infection prevention and control protocols exist in human healthcare settings. In contrast, infection prevention and control (IPC) standards are limited in veterinary medicine, necessitating further investigation. AIM Examine the possible transmission of carbapenem-resistant Acinetobacter spp. in a veterinary practice where a cat was diagnosed with an OXA-23-producing A. baumannii ST2 strain. METHODS Environmental samples together with nasal and hand swabs from the veterinary personnel were collected. All swabs were screened for the presence of extended-spectrum-β-lactamase- and carbapenemase-producing Enterobacterales, meticillin-resistant staphylococcus and multi-drug-resistant Acinetobacter spp. Whole-genome sequencing was performed for carbapenemase-producing strains. RESULTS Of the veterinary staff, 60% carried meticillin-resistant Staphylococcus epidermidis. Environmental evaluation showed that 40% (N=6/15) of the surfaces analysed by contact plates and 40% (N=8/20) by swabs failed the hygiene criteria. Assessment of the surfaces revealed contamination with five OXA-23-producing Acinetobacter spp. strains: an OXA-23-producing Acinetobacter schindleri on the weight scale in the waiting room; and four OXA-23-producing Acinetobacter lwoffii strains, on different surfaces of the treatment room. The blaOXA-23 gene was located on the same plasmid-carrying Tn2008 across the different Acinetobacter spp. strains. These plasmids closely resemble a previously described OXA-23-encoding plasmid from a human Portuguese nosocomial Acinetobacter pittii isolate. Distinctly, the OXA-23-producing A. baumannii ST2 clinical strain had the resistant gene located on Tn2006, possibly inserted on the chromosome. CONCLUSION The detection of an OXA-23-producing A. baumannii ST2 veterinary clinical strain is of concern for companion animal health and infection, prevention and control. This study established the dynamic of transmission of the plasmid-mediated blaOXA-23 gene on critical surfaces of a small animal veterinary practice. The genetic resemblance to a plasmid found in human nosocomial settings suggests a potential One Health link.
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Affiliation(s)
- J Moreira da Silva
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal; AL4AnimalS - Associate Laboratory for Animal and Veterinary Sciences, Lisbon, Portugal
| | - J Menezes
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal; AL4AnimalS - Associate Laboratory for Animal and Veterinary Sciences, Lisbon, Portugal
| | - L Fernandes
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal; AL4AnimalS - Associate Laboratory for Animal and Veterinary Sciences, Lisbon, Portugal
| | - C Marques
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal; AL4AnimalS - Associate Laboratory for Animal and Veterinary Sciences, Lisbon, Portugal; Faculty of Veterinary Medicine, Lusófona University, University Centre of Lisbon, Lisbon, Portugal
| | - S S Costa
- Global Health and Tropical Medicine, GHTM, Associate Laboratory in Translation and Innovation Towards Global Health, LA-REAL, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - D Timofte
- Institute of Infection, Veterinary and Ecological Sciences, Department of Veterinary Anatomy, Physiology and Pathology, School of Veterinary Science, University of Liverpool, Leahurst, UK
| | - A Amaral
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal; AL4AnimalS - Associate Laboratory for Animal and Veterinary Sciences, Lisbon, Portugal; Science and Technology School, University of Évora, Évora, Portugal
| | - C Pomba
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal; AL4AnimalS - Associate Laboratory for Animal and Veterinary Sciences, Lisbon, Portugal; Genevet™, Veterinary Molecular Diagnostic Laboratory, Carnaxide, Portugal.
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Costa-Ribeiro A, Azinheiro S, Mota S, Prado M, Lamas A, Garrido-Maestu A. Assessment of the presence of Acinetobacter spp. resistant to β-lactams in commercial ready-to-eat salad samples. Food Microbiol 2024; 118:104410. [PMID: 38049272 DOI: 10.1016/j.fm.2023.104410] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 12/06/2023]
Abstract
Acinetobacter baumannii is a well-known nosocomial infection causing agent. However, other Acinetobacter spp. have also been implicated in cases of human infection. Additionally, these bacteria are known for the development of antibiotic resistance thus making the treatment of the infections they cause, challenging. Due to their relevance in clinical setups less attention has been paid to their presence in foods, and its relation with infection/dissemination routes. In the current study commercial Ready-To-Eat (RTE) salads were analyzed seeking for antibiotic resistant Acinetobacter spp. A preliminary screening allowed us to recover Gram-negative bacteria resistant to β - lactams using cefotaxime, third generation cephalosporins, as the selective agent, and this was followed by identification with CHROMagar™ Acinetobacter and 16S rDNA sequencing. Finally, the isolates identified as Acinetobacter spp. were reanalyzed by PCR to determine the presence of nine potential Extended Spectrum β Lactamases (ESBL). Two commercial RTE salad brands were included in the study (2 batches per brand and 8 samples of each batch making a total of 32 independent samples), and compared against an organic lettuce. High concentrations of β - lactam, resistant bacteria were found in all the samples tested (5 log CFU/g). Additionally, 209 isolates were phenotypically characterized on CHROMagar Acinetobacter. Finally, PCR analysis identified the presence of different ESBL genes, being positive for blaACC, blaSHV, blaDHA and blaVEB; out of these, blaACC was the most prevalent. None of the isolates screened were positive for more than one gene. To conclude, it is important to highlight the fact that pathogenic species within the genus Acinetobacter spp., other than A. baumannii, have been identified bearing resistance genes not typically associated to these microorganisms highlight the importance of continuous surveillance.
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Affiliation(s)
- Ana Costa-Ribeiro
- Health and Environment Research Center, School of Health, Polytechnic Institute of Porto, R. Dr. Roberto Frias 712, 4200-465, Porto, Portugal; International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal; Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310, Vigo, Spain
| | - Sarah Azinheiro
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal; College of Pharmacy/School of Veterinary Sciences, University of Santiago de Compostela, Campus Vida, E-15782, Santiago de Compostela, Spain
| | - Sandra Mota
- Health and Environment Research Center, School of Health, Polytechnic Institute of Porto, R. Dr. Roberto Frias 712, 4200-465, Porto, Portugal
| | - Marta Prado
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal; Food Hygiene, Inspection and Control Laboratory (Lhica), Department of Analytical Chemistry, Nutrition and Bromatology, Veterinary School, Campus Terra, University of Santiago de Compostela, 27002, Lugo, Spain
| | - Alexandre Lamas
- Food Hygiene, Inspection and Control Laboratory (Lhica), Department of Analytical Chemistry, Nutrition and Bromatology, Veterinary School, Campus Terra, University of Santiago de Compostela, 27002, Lugo, Spain.
| | - Alejandro Garrido-Maestu
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal.
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Kasimova AA, Kolganova AS, Shashkov AS, Shneider MM, Mikhailova YV, Shelenkov AA, Popova AV, Knirel YA, Perepelov AV, Kenyon JJ. Structure of the K141 capsular polysaccharide produced by Acinetobacter baumannii isolate KZ1106 that carries KL141 at the chromosomal K locus. Carbohydr Res 2024; 538:109097. [PMID: 38555658 DOI: 10.1016/j.carres.2024.109097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/17/2024] [Accepted: 03/19/2024] [Indexed: 04/02/2024]
Abstract
The structure of the K141 type capsular polysaccharide (CPS) produced by Acinetobacter baumannii KZ1106, a clinical isolate recovered from Kazakhstan in 2016, was established by sugar analyses and one- and two-dimensional 1H and 13C NMR spectroscopy. The CPS was shown to consist of branched tetrasaccharide repeating units (K-units) with the following structure: This structure was found to be consistent with the genetic content of the KL141 CPS biosynthesis gene cluster at the chromosomal K locus in the KZ1106 whole genome sequence. Assignment of the encoded enzymes allowed the first sugar of the K unit to be identified, which revealed that the β-d-GlcpNAc-(1→3)-d-GlcpNAc bond is the linkage between K-units formed by the WzyKL141 polymerase.
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Affiliation(s)
- Anastasiya A Kasimova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Anna S Kolganova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia; D. I. Mendeleev University of Chemical Technology of Russia, Moscow, Russia
| | - Alexander S Shashkov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Mikhail M Shneider
- M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 119997, Moscow, Russia
| | | | | | - Anastasiya V Popova
- State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russia
| | - Yuriy A Knirel
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Andrey V Perepelov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Johanna J Kenyon
- School of Pharmacy and Medical Sciences, Health Group, Griffith University, Gold Coast, Australia; Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia.
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Lasarte-Monterrubio C, Guijarro-Sánchez P, Alonso-Garcia I, Outeda M, Maceiras R, González-Pinto L, Martínez-Guitián M, Fernández-Lozano C, Vázquez-Ucha JC, Bou G, Arca-Suárez J, Beceiro A. Epidemiology, resistance genomics and susceptibility of Acinetobacter species: results from the 2020 Spanish nationwide surveillance study. Euro Surveill 2024; 29:2300352. [PMID: 38606569 PMCID: PMC11010588 DOI: 10.2807/1560-7917.es.2024.29.15.2300352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 12/13/2023] [Indexed: 04/13/2024] Open
Abstract
BackgroundAs increasing antibiotic resistance in Acinetobacter baumannii poses a global healthcare challenge, understanding its evolution is crucial for effective control strategies.AimWe aimed to evaluate the epidemiology, antimicrobial susceptibility and main resistance mechanisms of Acinetobacter spp. in Spain in 2020, and to explore temporal trends of A. baumannii.MethodsWe collected 199 single-patient Acinetobacter spp. clinical isolates in 2020 from 18 Spanish tertiary hospitals. Minimum inhibitory concentrations (MICs) for nine antimicrobials were determined. Short-read sequencing was performed for all isolates, and targeted long-read sequencing for A. baumannii. Resistance mechanisms, phylogenetics and clonality were assessed. Findings on resistance rates and infection types were compared with data from 2000 and 2010.ResultsCefiderocol and colistin exhibited the highest activity against A. baumannii, although colistin susceptibility has significantly declined over 2 decades. A. non-baumannii strains were highly susceptible to most tested antibiotics. Of the A. baumannii isolates, 47.5% (56/118) were multidrug-resistant (MDR). Phylogeny and clonal relationship analysis of A. baumannii revealed five prevalent international clones, notably IC2 (ST2, n = 52; ST745, n = 4) and IC1 (ST1, n = 14), and some episodes of clonal dissemination. Genes bla OXA-23, bla OXA-58 and bla OXA-24/40 were identified in 49 (41.5%), eight (6.8%) and one (0.8%) A. baumannii isolates, respectively. ISAba1 was found upstream of the gene (a bla OXA-51-like) in 10 isolates.ConclusionsThe emergence of OXA-23-producing ST1 and ST2, the predominant MDR lineages, shows a pivotal shift in carbapenem-resistant A. baumannii (CRAB) epidemiology in Spain. Coupled with increased colistin resistance, these changes underscore notable alterations in regional antimicrobial resistance dynamics.
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Affiliation(s)
- Cristina Lasarte-Monterrubio
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Paula Guijarro-Sánchez
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Isaac Alonso-Garcia
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Michelle Outeda
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Romina Maceiras
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Lucia González-Pinto
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Marta Martínez-Guitián
- NANOBIOFAR, Centre for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Carlos Fernández-Lozano
- Department of Computer Science and Information Technologies, Faculty of Computer Science, Research Center of Information and Communication Technologies (CITIC), University of A Coruña, A Coruña, Spain
| | - Juan Carlos Vázquez-Ucha
- CIBER de Enfermedades Infecciosas (CIBERINFEC), A Coruña, Spain
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - German Bou
- CIBER de Enfermedades Infecciosas (CIBERINFEC), A Coruña, Spain
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Jorge Arca-Suárez
- CIBER de Enfermedades Infecciosas (CIBERINFEC), A Coruña, Spain
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
| | - Alejandro Beceiro
- CIBER de Enfermedades Infecciosas (CIBERINFEC), A Coruña, Spain
- Microbiology Department, A Coruña University Hospital (CHUAC), Institute of Biomedical Research of A Coruña (INIBIC), Spain
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20
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Toh YH, Lin GH. Roles of DJ41_1407 and DJ41_1408 in Acinetobacter baumannii ATCC19606 Virulence and Antibiotic Response. Int J Mol Sci 2024; 25:3862. [PMID: 38612672 PMCID: PMC11011904 DOI: 10.3390/ijms25073862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/26/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Acinetobacter baumannii is a major cause of nosocomial infections, and its highly adaptive nature and broad range of antibiotic resistance enable it to persist in hospital environments. A. baumannii often employs two-component systems (TCSs) to regulate adaptive responses and virulence-related traits. This study describes a previously uncharacterized TCS in the A. baumannii ATCC19606 strain, consisting of a transcriptional sensor, DJ41_1407, and its regulator, DJ41_1408, located adjacent to GacA of the GacSA TCS. Markerless mutagenesis was performed to construct DJ41_1407 and DJ41_1408 single and double mutants. DJ41_1408 was found to upregulate 49 genes and downregulate 43 genes, most of which were associated with carbon metabolism and other metabolic pathways, such as benzoate degradation. MEME analysis revealed a putative binding box for DJ41_1408, 5'TGTAAATRATTAYCAWTWAT3'. Colony size, motility, biofilm-forming ability, virulence, and antibiotic resistance of DJ41_1407 and DJ41_1408 single and double mutant strains were assessed against wild type. DJ41_1407 was found to enhance motility, while DJ41_1408 was found to upregulate biofilm-forming ability, and may also modulate antibiotic response. Both DJ41_1407 and DJ41_1408 suppressed virulence, based on results from a G. mellonella infection assay. These results showcase a novel A. baumannii TCS involved in metabolism, with effects on motility, biofilm-forming ability, virulence, and antibiotic response.
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Affiliation(s)
- Yee-Huan Toh
- Master Program in Biomedical Sciences, School of Medicine, Tzu Chi University, Hualien 970374, Taiwan;
| | - Guang-Huey Lin
- Department of Microbiology and Immunology, School of Medicine, Tzu Chi University, Hualien 970374, Taiwan
- International College, Tzu Chi University, Hualien 970374, Taiwan
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21
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Gu D, Wu Y, Chen K, Zhang Y, Ju X, Yan Z, Xie M, Chan EWC, Chen S, Ruan Z, Zhang R, Zhang J. Recovery and genetic characterization of clinically-relevant ST2 carbapenem-resistant Acinetobacter baumannii isolates from untreated hospital sewage in Zhejiang Province, China. Sci Total Environ 2024; 916:170058. [PMID: 38218490 DOI: 10.1016/j.scitotenv.2024.170058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/07/2024] [Accepted: 01/08/2024] [Indexed: 01/15/2024]
Abstract
The global transmission of carbapenem-resistant Acinetobacter baumannii (CRAB) poses a significant and grave threat to human health. To investigate the potential relationship between hospital sewage and the transmission of CRAB within healthcare facilities, isolates of Acinetobacter spp. obtained from untreated hospital sewage samples were subjected to antimicrobial susceptibility tests, genome sequencing, and bioinformatic and phylogenetic tree analysis, and that data were matched with those of the clinical isolates. Among the 70 Acinetobacter spp. sewage isolates tested, A. baumannii was the most prevalent and detectable in 5 hospitals, followed by A. nosocomialis and A. gerneri. Worryingly, 57.14 % (40/70) of the isolates were MDR, with 25.71 % (18/70) being resistant to carbapenem. When utilizing the Pasteur scheme, ST2 was the predominant type among these CRAB isolates, with Tn2006 (ΔISAba1-blaOXA-23-ATPase-yeeB-yeeA-ΔISAba1) and Tn2009 (ΔISAba1-blaOXA-23-ATPase-hp-parA-yeeC-hp-yeeB-ΔISAba1) being the key mobile genetic elements that encode carbapenem resistance. Seven A. gerneri isolates which harbored Tn2008 (ISAba1-blaOXA-23 -ATPase) and the blaPER-1 gene were also identified. Besides, an A. soil isolate was found to exhibit high-level of meropenem resistance (MIC ≥128 mg/L) and harbor a blaNDM-1 gene located in a core genetic structure of ISAba125-blaNDM-1-ble-trpF-dsbC-cutA. To investigate the genetic relatedness between isolates recovered from hospital sewage and those collected from ICUs, a phylogenetic tree was constructed for 242 clinical isolates and 9 sewage isolates. The results revealed the presence of two evolutionary clades, each containing isolates from both ICU and sewage water, suggesting that CRAB isolates in untreated sewage water were also the transmission clones or closely related evolutionary isolates recoverable in hospital settings. Findings in this work confirm that hospital sewage is a potential reservoir of CRAB.
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Affiliation(s)
- Danxia Gu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China; Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People's Hospital (Affiliated People's Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Yuchen Wu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China
| | - Kaichao Chen
- Department of Food Science and Nutrition, Faculty of Science, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Yanyan Zhang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China
| | - Xiaoyang Ju
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China
| | - Zelin Yan
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China
| | - Miaomiao Xie
- Department of Food Science and Nutrition, Faculty of Science, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Edward Wai Chi Chan
- Department of Food Science and Nutrition, Faculty of Science, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Sheng Chen
- Department of Food Science and Nutrition, Faculty of Science, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Zhi Ruan
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China; Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Rong Zhang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China.
| | - Jun Zhang
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China; Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China.
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22
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Bhavya JN, Anugna SS, Premanath R. Sub-inhibitory concentrations of colistin and imipenem impact the expression of biofilm-associated genes in Acinetobacter baumannii. Arch Microbiol 2024; 206:169. [PMID: 38489041 DOI: 10.1007/s00203-024-03869-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 03/17/2024]
Abstract
Acinetobacter baumannii is an opportunistic pathogen that is responsible for nosocomial infections. Imipenem and colistin are drugs that are commonly used to treat severe infections caused by A. baumannii, such as sepsis, ventilator-associated pneumonia, and bacteremia. However, some strains of A. baumannii have become resistant to these drugs, which is a concern for public health. Biofilms produced by A. baumannii increase their resistance to antibiotics and the cells within the inner layers of biofilm are exposed to sub-inhibitory concentrations (sub-MICs) of antibiotics. There is limited information available regarding how the genes of A. baumannii are linked to biofilm formation when the bacteria are exposed to sub-MICs of imipenem and colistin. Thus, this study's objective was to explore this relationship by examining the genes involved in biofilm formation in A. baumannii when exposed to low levels of imipenem and colistin. The study found that exposing an isolate of A. baumannii to low levels of these drugs caused changes in their drug susceptibility pattern. The relative gene expression profiles of the biofilm-associated genes exhibited a change in their expression profile during short-term and long-term exposure. This study highlights the potential consequences of overuse and misuse of antibiotics, which can help bacteria become resistant to these drugs.
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Affiliation(s)
- J N Bhavya
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research, Paneer Campus, Deralakatte, Mangaluru, Karnataka, 575018, India
| | - Sureddi Sai Anugna
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research, Paneer Campus, Deralakatte, Mangaluru, Karnataka, 575018, India
| | - Ramya Premanath
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research, Paneer Campus, Deralakatte, Mangaluru, Karnataka, 575018, India.
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23
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VanOtterloo LM, Macias LA, Powers MJ, Brodbelt JS, Trent MS. Characterization of Acinetobacter baumannii core oligosaccharide synthesis reveals novel aspects of lipooligosaccharide assembly. mBio 2024; 15:e0301323. [PMID: 38349180 PMCID: PMC10936431 DOI: 10.1128/mbio.03013-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/12/2024] [Indexed: 03/14/2024] Open
Abstract
A fundamental feature of Gram-negative bacteria is their outer membrane that protects the cell against environmental stressors. This defense is predominantly due to its asymmetry, with glycerophospholipids located in the inner leaflet and lipopolysaccharide (LPS) or lipooligosaccharide (LOS) confined to the outer leaflet. LPS consists of a lipid A anchor, a core oligosaccharide, and a distal O-antigen while LOS lacks O-antigen. While LPS/LOS is typically essential for growth, this is not the case for Acinetobacter baumannii. Despite this unique property, the synthesis of the core oligosaccharide of A. baumannii LOS is not well-described. Here, we characterized the LOS chemotypes of A. baumannii strains with mutations in a predicted core oligosaccharide locus via tandem mass spectrometry. This allowed for an extensive identification of genes required for core assembly that can be exploited to generate precise structural LOS modifications in many A. baumannii strains. We further investigated two chemotypically identical yet phenotypically distinct mutants, ∆2903 and ∆lpsB, that exposed a possible link between LOS and the peptidoglycan cell wall-two cell envelope components whose coordination has not yet been described in A. baumannii. Selective reconstruction of the core oligosaccharide via expression of 2903 and LpsB revealed that these proteins rely on each other for the unusual tandem transfer of two residues, KdoIII and N-acetylglucosaminuronic acid. The data presented not only allow for better usage of A. baumannii as a tool to study outer membrane integrity but also provide further evidence for a novel mechanism of core oligosaccharide assembly. IMPORTANCE Acinetobacter baumannii is a multidrug-resistant pathogen that produces lipooligosaccharide (LOS), a glycolipid that confers protective asymmetry to the bacterial outer membrane. The core oligosaccharide is a ubiquitous component of LOS that typically follows a well-established model of synthesis. In addition to providing an extensive analysis of the genes involved in the synthesis of the core region, we demonstrate that this organism has evidently diverged from the long-held archetype of core synthesis. Moreover, our data suggest that A. baumannii LOS assembly is important for cell division and likely intersects with the synthesis of the peptidoglycan cell wall, another essential component of the Gram-negative cell envelope. This connection between LOS and cell wall synthesis provides an intriguing foundation for a unique method of outer membrane biogenesis and cell envelope coordination.
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Affiliation(s)
- Leah M. VanOtterloo
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
| | - Luis A. Macias
- Department of Chemistry, University of Texas at Austin, Austin, Texas, USA
| | - Matthew J. Powers
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
| | | | - M. Stephen Trent
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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24
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Liao J, Qi Q, Kuang L, Zhou Y, Xiao Q, Liu T, Wang X, Guo L, Jiang Y. Chloramphenicol Binding Sites of Acinetobacter baumannii Chloramphenicol Acetyltransferase CatB8. ACS Infect Dis 2024; 10:870-878. [PMID: 38311919 DOI: 10.1021/acsinfecdis.3c00359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Acinetobacter baumannii is a multidrug-resistant pathogen that has become one of the most challenging pathogens in global healthcare. Several antibiotic-resistant genes, including catB8, have been identified in the A. baumannii genome. CatB8 protein, one of the chloramphenicol acetyltransferases (Cats), is encoded by the catB8 gene. Cats can convert chloramphenicol (chl) to 3-acetyl-chl, leading to bacterial resistance to chl. Here, we present the high-resolution cocrystal structure of CatB8 with chl. The structure that we resolved showed that each monomer of CatB8 binds to four chl molecules, while its homologous protein only binds to one chl molecule. One of the newly discovered chl binding site overlaps with the site of another substrate, acetyl-CoA. Through structure-based biochemical analyses, we identified key residues for chl recruiting and acetylation of chl in CatB8. Our work is of significant importance for understanding the drug resistance of A. baumannii and the effectiveness of antibiotic treatment.
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Affiliation(s)
- Jing Liao
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Qianqian Qi
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Linghan Kuang
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu 610041, Sichuan, China
| | - Yanxia Zhou
- West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, Sichuan, China
| | - Qingjie Xiao
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China
| | - Ting Liu
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu 610041, Sichuan, China
| | - Xiang Wang
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Li Guo
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yongmei Jiang
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu 610041, Sichuan, China
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25
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Tan Y, Su J, Luo D, Liang B, Liu S, Zeng H. Isolation and genome-wide analysis of the novel Acinetobacter baumannii bacteriophage vB_AbaM_AB3P2. Arch Virol 2024; 169:66. [PMID: 38451338 DOI: 10.1007/s00705-024-05986-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/12/2024] [Indexed: 03/08/2024]
Abstract
A lytic Acinetobacter baumannii phage, isolate vB_AbaM_AB3P2, was isolated from a sewage treatment plant in China. A. baumannii phage vB_AbaM_AB3P2 has a dsDNA genome that is 44,824 bp in length with a G + C content of 37.75%. Ninety-six open reading frames were identified, and no genes for antibiotic resistance or virulence factors were found. Genomic and phylogenetic analysis of this phage revealed that it represents a new species in the genus Obolenskvirus. Phage vB_AbaM_AB3P2 has a short latent period (10 min) and high stability at 30-70°C and pH 2-10 and is potentially useful for controlling multi-drug-resistant A. baumannii.
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Affiliation(s)
- Yujing Tan
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Waihuan West Road 100, Guangzhou, Guangdong Province, 510006, China
| | - Jianhui Su
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Waihuan West Road 100, Guangzhou, Guangdong Province, 510006, China
| | - Dandan Luo
- Yunnan Zhinong High-technology Company, Limited, Kunming, 650000, China
| | - Bingshao Liang
- Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Shenshen Liu
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Waihuan West Road 100, Guangzhou, Guangdong Province, 510006, China
| | - Haiyan Zeng
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Waihuan West Road 100, Guangzhou, Guangdong Province, 510006, China.
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26
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Kim M, Le MT, Fan L, Campbell C, Sen S, Capdevila DA, Stemmler TL, Giedroc DP. Characterization of the Zinc Uptake Repressor (Zur) from Acinetobacter baumannii. Biochemistry 2024; 63:660-670. [PMID: 38385972 PMCID: PMC11019503 DOI: 10.1021/acs.biochem.3c00679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Bacterial cells tightly regulate the intracellular concentrations of essential transition metal ions by deploying a panel of metal-regulated transcriptional repressors and activators that bind to operator-promoter regions upstream of regulated genes. Like other zinc uptake regulator (Zur) proteins, Acinetobacter baumannii Zur represses transcription of its regulon when ZnII is replete and binds more weakly to DNA when ZnII is limiting. Previous studies established that Zur proteins are homodimeric and harbor at least two metal sites per protomer or four per dimer. CdII X-ray absorption spectroscopy (XAS) of the Cd2Zn2 AbZur metalloderivative with CdII bound to the allosteric sites reveals a S(N/O)3 first coordination shell. Site-directed mutagenesis suggests that H89 and C100 from the N-terminal DNA binding domain and H107 and E122 from the C-terminal dimerization domain comprise the regulatory metal site. KZn for this allosteric site is 6.0 (±2.2) × 1012 M-1 with a functional "division of labor" among the four metal ligands. N-terminal domain ligands H89 and C100 contribute far more to KZn than H107 and E122, while C100S AbZur uniquely fails to bind to DNA tightly as measured by an in vitro transcription assay. The heterotropic allosteric coupling free energy, ΔGc, is negative, consistent with a higher KZn for the AbZur-DNA complex and defining a bioavailable ZnII set-point of ≈6 × 10-14 M. Small-angle X-ray scattering (SAXS) experiments reveal that only the wild-type Zn homodimer undergoes allosteric switching, while the C100S AbZur fails to switch. These data collectively suggest that switching to a high affinity DNA-binding conformation involves a rotation/translation of one protomer relative to the other in a way that is dependent on the integrity of C100. We place these findings in the context of other Zur proteins and Fur family repressors more broadly.
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Affiliation(s)
- Minyong Kim
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - My Tra Le
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Lixin Fan
- Basic Science Program, Frederick National Laboratory for Cancer Research, SAXS Core Facility of the National Cancer Institute, Frederick, Maryland 21702, United States
| | - Courtney Campbell
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201-2417, United States
| | - Sambuddha Sen
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Daiana A Capdevila
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), C1405 BWE Buenos Aires, Argentina
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201-2417, United States
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
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Raddaoui A, Mabrouk A, Chebbi Y, Frigui S, Salah Abbassi M, Achour W, Thabet L. Co-occurrence of blaNDM-1 and blaOXA-23 in carbapenemase-producing Acinetobacter baumannii belonging to high-risk lineages isolated from burn patients in Tunisia. J Appl Microbiol 2024; 135:lxae039. [PMID: 38346864 DOI: 10.1093/jambio/lxae039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 01/10/2024] [Accepted: 02/09/2024] [Indexed: 03/21/2024]
Abstract
AIMS Carbapenem-resistant Acinetobacter baumannii (CR-Ab) is an important cause of infections in burn patients. This study aimed to characterize the antimicrobial susceptibility pattern of CR-Ab isolated from burns in Burn Intensive Care Unit (BICU) of the Trauma and Burn Centre of Ben Arous, to determine the prevalence of β-lactamase-encoding genes and to search eventual genetic relatedness of CR-Ab strains. METHODS AND RESULTS From 15 December 2016 to 2 April 2017, all nonduplicated CR-Ab isolated in burn patients in the BICU were screened by simplex Polymerase Chain Reaction (PCR) for the class A, B, C, and D β-lactamase genes. Sequencing was performed for NDM gene only. Genetic relatedness was determined by using pulsed field gel electrophoresis (PFGE) and by multilocus sequence typing. During the study period, 34 strains of CR-Ab were isolated in burns, mainly in blood culture (n = 14) and central vascular catheter (n = 10). CR-Ab strains were susceptible to colistin but resistant to amikacin (91%), ciprofloxacin (100%), rifampicin (97%), and trimethoprim-sulfamethoxazole (100%). All strains harbored blaOXA-51-like and blaOXA-23 genes, only or associated to blaGES (n = 26; 76%), blaADC (n = 20; 59%), blaPER-1 (n = 6; 18%) or/and blaNDM-1 (n = 3; 9%). PFGE identified 16 different clusters and revealed that most strains belonged to one major cluster A (n = 15; 44.1%). Among NDM-1 isolates, two were clonally related in PFGE and belonged to two single locus variant sequence type ST-6 and ST-85. CONCLUSIONS This is the first description of clonally related NDM-1 and OXA-23-producing A. baumannii strains in the largest Tunisian BICU associated with two single locus variant sequence types ST6 and ST85.
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Affiliation(s)
- Anis Raddaoui
- Laboratory Ward, National Bone Marrow Transplant Center, 1006 Tunis, Tunisia
- Faculty of Medicine of Tunis, LR18ES39, University of Tunis El Manar, 1006 Tunis, Tunisia
| | - Aymen Mabrouk
- Laboratory Ward, National Bone Marrow Transplant Center, 1006 Tunis, Tunisia
- Faculty of Medicine of Tunis, LR18ES39, University of Tunis El Manar, 1006 Tunis, Tunisia
| | - Yosra Chebbi
- Laboratory Ward, National Bone Marrow Transplant Center, 1006 Tunis, Tunisia
- Faculty of Medicine of Tunis, LR18ES39, University of Tunis El Manar, 1006 Tunis, Tunisia
| | - Siwar Frigui
- Laboratory Ward, National Bone Marrow Transplant Center, 1006 Tunis, Tunisia
- Faculty of Medicine of Tunis, LR18ES39, University of Tunis El Manar, 1006 Tunis, Tunisia
| | - Mohamed Salah Abbassi
- Faculty of Medicine of Tunis, Laboratory of Antibiotic Resistance LR99ES09, University of Tunis El Manar, 1006 Tunis, Tunisia
- Institute of Veterinary Research of Tunisia, University of Tunis El Manar, 1006 Tunis, Tunisia
| | - Wafa Achour
- Laboratory Ward, National Bone Marrow Transplant Center, 1006 Tunis, Tunisia
- Faculty of Medicine of Tunis, LR18ES39, University of Tunis El Manar, 1006 Tunis, Tunisia
| | - Lamia Thabet
- Laboratory Ward, Traumatology and Great Burned Center, 2074 Ben Arous, Tunisia
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Kasimova AA, Shashkov AS, Shneider MM, Sheck EA, Mikhailova YV, Shelenkov AA, Popova AV, Knirel YA, Kenyon JJ. The Acinetobacter baumannii K239 capsular polysaccharide includes heptasaccharide units that are structurally related to K86 but joined by different linkages formed by different Wzy polymerases. Int J Biol Macromol 2024; 262:130045. [PMID: 38336317 DOI: 10.1016/j.ijbiomac.2024.130045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 12/16/2023] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
The K239 type capsular polysaccharide (CPS) isolated from Acinetobacter baumannii isolate MAR19-4435 was studied by sugar analysis, one- and two-dimensional 1H and 13C NMR spectroscopy. K239 consists of branched heptasaccharide repeats (K-units) comprised of five residues of l-rhamnose (l-Rhap), and one residue each of d-glucuronic acid (d-GlcpA) and N-acetyl-d-glucosamine (d-GlcpNAc). The structure of K239 is closely related to that of the A. baumannii K86 CPS type, though the two differ in the 2,3-substitution patterns on the l-Rhap residue that is involved in the linkage between K-units in the CPS polymer. This structural difference was attributed to the presence of a gtr221 glycosyltransferase gene and a wzyKL239 polymerase gene in KL239 that replaces the gtr80 and wzyKL86 genes in the KL86 CPS biosynthesis gene cluster. Comparison of the two structures established the role of a novel WzyKL239 polymerase encoded by KL239 that forms the β-d-GlcpNAc-(1→2)-l-Rhap linkage between K239 units. A. baumannii MAR19-4435 was found to be non-susceptible to infection by the APK86 bacteriophage, which encodes a depolymerase that specifically cleaves the linkage between K-units in the K86 CPS, indicating that the difference in 2,3-substitution of l-Rhap influences the susceptibility of this isolate to bacteriophage activity.
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Affiliation(s)
- Anastasiya A Kasimova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexander S Shashkov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Mikhail M Shneider
- M. M. Shemyakin and Y. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 119997 Moscow, Russia
| | - Eugenii A Sheck
- Institute of Antimicrobial Chemotherapy (IAC), Smolensk State Medical University (SSMU), Kirova St. 46a, Smolensk 214019, Russia
| | | | | | - Anastasiya V Popova
- State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russia
| | - Yuriy A Knirel
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Johanna J Kenyon
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia.
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Sheikh AA, Schneiderman D, Sykes EME, Kumar A, Chen W, Lapen DR, Khan IUH. Three novel multiplex PCR assays for rapid detection of virulence, antimicrobial resistance, and toxin genes in Acinetobacter calcoaceticus-baumannii complex species. Lett Appl Microbiol 2024; 77:ovae027. [PMID: 38460955 DOI: 10.1093/lambio/ovae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/01/2024] [Accepted: 03/08/2024] [Indexed: 03/11/2024]
Abstract
The Acinetobacter calcoaceticus-baumannii (ACB) complex is an often-overlooked group of nosocomial pathogens with a significant environmental presence. Rapid molecular screening methods for virulence, antimicrobial resistance, and toxin (VAT) genes are required to investigate the potential pathogenicity of environmental isolates. This study aimed to develop and apply novel ACB complex-specific multiplex PCR (mPCR) primers and protocols for the rapid detection of eight VAT genes. We optimized three single-tube mPCR assays using reference DNA from ACB complex and other Acinetobacter species. These assays were then applied to detect VAT genes in cultured ACB complex isolates recovered from clinical and environmental sources. Widespread detection of VAT genes in environmental isolates confirmed the validity, functionality, and applicability of these novel assays. Overall, the three newly developed ACB complex species-specific mPCR assays are rapid and simple tools that can be adopted in diagnostic and clinical lab settings. The detection of VAT genes in environmental isolates suggests that environmental niches could serve as a reservoir for potentially pathogenic ACB complex and warrants further investigation. The newly developed mPCR assays are specific, sensitive, and efficient, making them well-suited for high-throughput screening in epidemiological studies and evaluating the potential pathogenicity of ACB complex recovered from various sources.
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Affiliation(s)
- Alexander A Sheikh
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, K1A 0C6, ON, Canada
| | - Danielle Schneiderman
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, K1A 0C6, ON, Canada
| | - Ellen M E Sykes
- Department of Microbiology, University of Manitoba, Winnipeg, R3T 2N2, MB, Canada
| | - Ayush Kumar
- Department of Microbiology, University of Manitoba, Winnipeg, R3T 2N2, MB, Canada
| | - Wen Chen
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, K1A 0C6, ON, Canada
| | - David R Lapen
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, K1A 0C6, ON, Canada
| | - Izhar U H Khan
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, K1A 0C6, ON, Canada
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Lucidi M, Imperi F, Artuso I, Capecchi G, Spagnoli C, Visaggio D, Rampioni G, Leoni L, Visca P. Phage-mediated colistin resistance in Acinetobacter baumannii. Drug Resist Updat 2024; 73:101061. [PMID: 38301486 DOI: 10.1016/j.drup.2024.101061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/03/2024]
Abstract
AIMS Antimicrobial resistance is a global threat to human health, and Acinetobacter baumannii is a paradigmatic example of how rapidly bacteria become resistant to clinically relevant antimicrobials. The emergence of multidrug-resistant A. baumannii strains has forced the revival of colistin as a last-resort drug, suddenly leading to the emergence of colistin resistance. We investigated the genetic and molecular basis of colistin resistance in A. baumannii, and the mechanisms implicated in its regulation and dissemination. METHODS Comparative genomic analysis was combined with genetic, biochemical, and phenotypic assays to characterize Φ19606, an A. baumannii temperate bacteriophage that carries a colistin resistance gene. RESULTS Ф19606 was detected in 41% of 523 A. baumannii complete genomes and demonstrated to act as a mobile vehicle of the colistin resistance gene eptA1, encoding a functional lipid A phosphoethanolamine transferase. The eptA1 gene is coregulated with its chromosomal homolog pmrC via the PmrAB two-component system and confers colistin resistance when induced by low calcium and magnesium levels. Resistance selection assays showed that the eptA1-harbouring phage Ф19606 promotes the emergence of spontaneous colistin-resistant mutants. CONCLUSIONS Φ19606 is an unprecedented example of a self-transmissible phage vector implicated in the dissemination of colistin resistance.
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Affiliation(s)
- Massimiliano Lucidi
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy; NBFC, National Biodiversity Future Center, piazza Marina 61, 90133 Palermo, Italy.
| | - Francesco Imperi
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy; NBFC, National Biodiversity Future Center, piazza Marina 61, 90133 Palermo, Italy; Santa Lucia Foundation IRCCS, Via Ardeatina 306/354, 00179 Rome, Italy
| | - Irene Artuso
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy
| | - Giulia Capecchi
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy
| | - Cinzia Spagnoli
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy
| | - Daniela Visaggio
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy; NBFC, National Biodiversity Future Center, piazza Marina 61, 90133 Palermo, Italy; Santa Lucia Foundation IRCCS, Via Ardeatina 306/354, 00179 Rome, Italy
| | - Giordano Rampioni
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy; Santa Lucia Foundation IRCCS, Via Ardeatina 306/354, 00179 Rome, Italy
| | - Livia Leoni
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy
| | - Paolo Visca
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy; NBFC, National Biodiversity Future Center, piazza Marina 61, 90133 Palermo, Italy; Santa Lucia Foundation IRCCS, Via Ardeatina 306/354, 00179 Rome, Italy.
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Tobin LA, Jarocki VM, Kenyon J, Drigo B, Donner E, Djordjevic SP, Hamidian M. Genomic analysis of diverse environmental Acinetobacter isolates identifies plasmids, antibiotic resistance genes, and capsular polysaccharides shared with clinical strains. Appl Environ Microbiol 2024; 90:e0165423. [PMID: 38206028 PMCID: PMC10885009 DOI: 10.1128/aem.01654-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 11/30/2023] [Indexed: 01/12/2024] Open
Abstract
Acinetobacter baumannii, an important pathogen known for its widespread antibiotic resistance, has been the focus of extensive research within its genus, primarily involving clinical isolates. Consequently, data on environmental A. baumannii and other Acinetobacter species remain limited. Here, we utilized Illumina and Nanopore sequencing to analyze the genomes of 10 Acinetobacter isolates representing 6 different species sourced from aquatic environments in South Australia. All 10 isolates were phylogenetically distinct compared to clinical and other non-clinical Acinetobacter strains, often tens of thousands of single-nucleotide polymorphisms from their nearest neighbors. Despite the genetic divergence, we identified pdif modules (sections of mobilized DNA) carrying clinically important antimicrobial resistance genes in species other than A. baumannii, including carbapenemase oxa58, tetracycline resistance gene tet(39), and macrolide resistance genes msr(E)-mph(E). These pdif modules were located on plasmids with high sequence identity to those circulating in globally distributed A. baumannii ST1 and ST2 clones. The environmental A. baumannii isolate characterized here (SAAb472; ST350) did not possess any native plasmids; however, it could capture two clinically important plasmids (pRAY and pACICU2) with high transfer frequencies. Furthermore, A. baumannii SAAb472 possessed virulence genes and a capsular polysaccharide type analogous to clinical strains. Our findings highlight the potential for environmental Acinetobacter species to acquire and disseminate clinically important antimicrobial resistance genes, underscoring the need for further research into the ecology and evolution of this important genus.IMPORTANCEAntimicrobial resistance (AMR) is a global threat to human, animal, and environmental health. Studying AMR in environmental bacteria is crucial to understand the emergence and dissemination of resistance genes and pathogens, and to identify potential reservoirs and transmission routes. This study provides novel insights into the genomic diversity and AMR potential of environmental Acinetobacter species. By comparing the genomes of aquatic Acinetobacter isolates with clinical and non-clinical strains, we revealed that they are highly divergent yet carry pdif modules that encode resistance to antibiotics commonly used in clinical settings. We also demonstrated that an environmental A. baumannii isolate can acquire clinically relevant plasmids and carries virulence factors similar to those of hospital-associated strains. These findings suggest that environmental Acinetobacter species may serve as reservoirs and vectors of clinically important genes. Consequently, further research is warranted to comprehensively understand the ecology and evolution of this genus.
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Affiliation(s)
- Liam A. Tobin
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Veronica M. Jarocki
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, New South Wales, Australia
- The Australian Centre for Genomic Epidemiological Microbiology, University of Technology Sydney, Ultimo, Australia
| | - Johanna Kenyon
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Barbara Drigo
- Future Industries Institute, University of South Australia, Mawson Lakes, SA, Australia
- UniSA STEM, University of South Australia, Mawson Lakes, SA, Australia
| | - Erica Donner
- Future Industries Institute, University of South Australia, Mawson Lakes, SA, Australia
- Cooperative Research Centre for Solving Antimicrobial Resistance in Agribusiness, Food, and Environments (CRC SAAFE), Adelaide, SA, Australia
| | - Steven P. Djordjevic
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, New South Wales, Australia
- The Australian Centre for Genomic Epidemiological Microbiology, University of Technology Sydney, Ultimo, Australia
| | - Mehrad Hamidian
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, New South Wales, Australia
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Menon ND, Poudel S, Sastry AV, Rychel K, Szubin R, Dillon N, Tsunemoto H, Hirose Y, Nair BG, Kumar GB, Palsson BO, Nizet V. Independent component analysis reveals 49 independently modulated gene sets within the global transcriptional regulatory architecture of multidrug-resistant Acinetobacter baumannii. mSystems 2024; 9:e0060623. [PMID: 38189271 PMCID: PMC10878099 DOI: 10.1128/msystems.00606-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 11/29/2023] [Indexed: 01/09/2024] Open
Abstract
Acinetobacter baumannii causes severe infections in humans, resists multiple antibiotics, and survives in stressful environmental conditions due to modulations of its complex transcriptional regulatory network (TRN). Unfortunately, our global understanding of the TRN in this emerging opportunistic pathogen is limited. Here, we apply independent component analysis, an unsupervised machine learning method, to a compendium of 139 RNA-seq data sets of three multidrug-resistant A. baumannii international clonal complex I strains (AB5075, AYE, and AB0057). This analysis allows us to define 49 independently modulated gene sets, which we call iModulons. Analysis of the identified A. baumannii iModulons reveals validating parallels to previously defined biological operons/regulons and provides a framework for defining unknown regulons. By utilizing the iModulons, we uncover potential mechanisms for a RpoS-independent general stress response, define global stress-virulence trade-offs, and identify conditions that may induce plasmid-borne multidrug resistance. The iModulons provide a model of the TRN that emphasizes the importance of transcriptional regulation of virulence phenotypes in A. baumannii. Furthermore, they suggest the possibility of future interventions to guide gene expression toward diminished pathogenic potential.IMPORTANCEThe rise in hospital outbreaks of multidrug-resistant Acinetobacter baumannii infections underscores the urgent need for alternatives to traditional broad-spectrum antibiotic therapies. The success of A. baumannii as a significant nosocomial pathogen is largely attributed to its ability to resist antibiotics and survive environmental stressors. However, there is limited literature available on the global, complex regulatory circuitry that shapes these phenotypes. Computational tools that can assist in the elucidation of A. baumannii's transcriptional regulatory network architecture can provide much-needed context for a comprehensive understanding of pathogenesis and virulence, as well as for the development of targeted therapies that modulate these pathways.
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Affiliation(s)
- Nitasha D. Menon
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kerala, India
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Saugat Poudel
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Anand V. Sastry
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Kevin Rychel
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Richard Szubin
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Nicholas Dillon
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Biological Sciences, University of Texas at Dallas, Dallas, Texas, USA
| | - Hannah Tsunemoto
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA
| | - Yujiro Hirose
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Microbiology, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan
| | - Bipin G. Nair
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kerala, India
| | - Geetha B. Kumar
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kerala, India
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Victor Nizet
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
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Wang M, Ge L, Chen L, Komarow L, Hanson B, Reyes J, Cober E, Alenazi T, Zong Z, Xie Q, Liu Z, Li L, Yu Y, Gao H, Kanj SS, Figueroa J, Herc E, Cordova E, Weston G, Ananth Tambyah P, Garcia-Diaz J, Kaye KS, Dhar S, Munita JM, Salata RA, Vilchez S, Stryjewski ME, Villegas Botero MV, Iovleva A, Evans SR, Baum K, Hill C, Kreiswirth BN, Patel R, Paterson DL, Arias CA, Bonomo RA, Chambers HF, Fowler VG, Satlin MJ, van Duin D, Doi Y. Clinical Outcomes and Bacterial Characteristics of Carbapenem-resistant Acinetobacter baumannii Among Patients From Different Global Regions. Clin Infect Dis 2024; 78:248-258. [PMID: 37738153 PMCID: PMC10874260 DOI: 10.1093/cid/ciad556] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/05/2023] [Accepted: 09/15/2023] [Indexed: 09/24/2023] Open
Abstract
BACKGROUND Carbapenem-resistant Acinetobacter baumannii (CRAb) is 1 of the most problematic antimicrobial-resistant bacteria. We sought to elucidate the international epidemiology and clinical impact of CRAb. METHODS In a prospective observational cohort study, 842 hospitalized patients with a clinical CRAb culture were enrolled at 46 hospitals in five global regions between 2017 and 2019. The primary outcome was all-cause mortality at 30 days from the index culture. The strains underwent whole-genome analysis. RESULTS Of 842 cases, 536 (64%) represented infection. By 30 days, 128 (24%) of the infected patients died, ranging from 1 (6%) of 18 in Australia-Singapore to 54 (25%) of 216 in the United States and 24 (49%) of 49 in South-Central America, whereas 42 (14%) of non-infected patients died. Bacteremia was associated with a higher risk of death compared with other types of infection (40 [42%] of 96 vs 88 [20%] of 440). In a multivariable logistic regression analysis, bloodstream infection and higher age-adjusted Charlson comorbidity index were independently associated with 30-day mortality. Clonal group 2 (CG2) strains predominated except in South-Central America, ranging from 216 (59%) of 369 in the United States to 282 (97%) of 291 in China. Acquired carbapenemase genes were carried by 769 (91%) of the 842 isolates. CG2 strains were significantly associated with higher levels of meropenem resistance, yet non-CG2 cases were over-represented among the deaths compared with CG2 cases. CONCLUSIONS CRAb infection types and clinical outcomes differed significantly across regions. Although CG2 strains remained predominant, non-CG2 strains were associated with higher mortality. Clinical Trials Registration. NCT03646227.
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Affiliation(s)
- Minggui Wang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Health Commission of People's Republic of China,Shanghai, China
| | - Lizhao Ge
- The Biostatistics Center, George Washington University, Rockville, Maryland, USA
| | - Liang Chen
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, New Jersey, USA
| | - Lauren Komarow
- The Biostatistics Center, George Washington University, Rockville, Maryland, USA
| | - Blake Hanson
- Center for Infectious Diseases and Microbial Genomics, UTHealth, McGovern School of Medicine at Houston, Houston, Texas, USA
| | - Jinnethe Reyes
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogotá, Colombia
| | - Eric Cober
- Department of Infectious Diseases, Cleveland Clinic, Cleveland, Ohio, USA
| | - Thamer Alenazi
- College of Medicine, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Zhiyong Zong
- Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China
| | - Qing Xie
- Department of Infectious Disease, Ruijin Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Zhengyin Liu
- Infectious Disease Section, Department of Internal Medicine, Peking Union Medical College Hospital, Beijing, China
| | - Lanjuan Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital of Medical School of Zhejiang University, Hangzhou, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hainv Gao
- Department of Infectious Diseases, Shulan Hangzhou Hospital, Hangzhou, China
| | - Souha S Kanj
- Division of Infectious Diseases, American University of Beirut Medical Center, Beirut, Lebanon
| | - Jairo Figueroa
- Department of Infectious Diseases, Hospital Universitario Erasmo Meoz ESE, Cúcuta, Colombia
| | - Erica Herc
- Division of Infectious Diseases, Department of Medicine, Henry Ford Hospital, Detroit, Michigan, USA
| | - Ezequiel Cordova
- Infectious Diseases Unit, Hospital Cosme Argerich de Buenos Aires, Buenos Aires, Argentina
| | - Gregory Weston
- Division of Infectious Diseases, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Paul Ananth Tambyah
- Infectious Diseases Translational Research Programme, National University of Singapore, Singapore, Singapore
| | - Julia Garcia-Diaz
- Division of Infectious Diseases, Ochsner Medical Center, New Orleans, Louisiana, USA
| | - Keith S Kaye
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Division of Allergy, Immunology and Infectious Diseases, Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| | - Sorabh Dhar
- Division of Infectious Disease, School of Medicine, Wayne State University, Detroit, Michigan, USA
| | - Jose M Munita
- Millennium Initiative for Collaborative Research on Bacterial Resistance (MICROB-R), Instituto de Ciencias e Innovación en Medicina, Facultad de Medicine, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Robert A Salata
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Samuel Vilchez
- Center for Infectious Disease Research, Department of Microbiology and Parasitology, School of Medicine, National Autonomous University of Nicaragua, Leon, Nicaragua
| | - Martin E Stryjewski
- Department of Medicine and Division of Infectious Diseases, Centro de Educación Médica e Investigaciones Clínicas, Buenos Aires, Argentina
| | | | - Alina Iovleva
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Scott R Evans
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Health Commission of People's Republic of China,Shanghai, China
- Department of Biostatics and Bioinformatics, Milken Institute School of Public Health, George Washington University, Washington, District of Columbia, USA
| | - Keri Baum
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
| | - Carol Hill
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
| | - Barry N Kreiswirth
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
- Division of Public Health, Infectious Diseases and Occupational Medicine, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - David L Paterson
- Department of Infectious Diseases, University of Queensland Centre for Clinical Research, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Cesar A Arias
- Division of Infectious Diseases, Houston Methodist Hospital and Houston Methodist Research Institute, Houston, Texas, USA
- Center for Infectious Diseases Research, Houston Methodist Hospital and Houston Methodist Research Institute, Houston, Texas, USA
| | - Robert A Bonomo
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Case Western Reserve University VA Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Henry F Chambers
- Department of Medicine, University of California SanFrancisco, San Francisco, California, USA
| | - Vance G Fowler
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
| | - Michael J Satlin
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, New York, USA
| | - David van Duin
- Division of Infectious Diseases, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Yohei Doi
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Infectious Diseases, Fujita Health University School of Medicine, Aichi, Japan
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Aranzamendi M, Xanthopoulou K, Sánchez-Urtaza S, Burgwinkel T, Arazo del Pino R, Lucaßen K, Pérez-Vázquez M, Oteo-Iglesias J, Sota M, Marimón JM, Seifert H, Higgins PG, Gallego L. Genomic Surveillance Uncovers a 10-Year Persistence of an OXA-24/40 Acinetobacter baumannii Clone in a Tertiary Hospital in Northern Spain. Int J Mol Sci 2024; 25:2333. [PMID: 38397011 PMCID: PMC10889530 DOI: 10.3390/ijms25042333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Infections caused by carbapenem-resistant Acinetobacter baumannii are a global threat causing a high number of fatal infections. This microorganism can also easily acquire antibiotic resistance determinants, making the treatment of infections a big challenge, and has the ability to persist in the hospital environment under a wide range of conditions. The objective of this work was to study the molecular epidemiology and genetic characteristics of two blaOXA24/40Acinetobacter baumannii outbreaks (2009 and 2020-21) at a tertiary hospital in Northern Spain. Thirty-six isolates were investigated and genotypically screened by Whole Genome Sequencing to analyse the resistome and virulome. Isolates were resistant to carbapenems, aminoglycosides and fluoroquinolones. Multi-Locus Sequence Typing analysis identified that Outbreak 1 was mainly produced by isolates belonging to ST3Pas/ST106Oxf (IC3) containing blaOXA24/40, blaOXA71 and blaADC119. Outbreak 2 isolates were exclusively ST2Pas/ST801Oxf (IC2) blaOXA24/40, blaOXA66 and blaADC30, the same genotype seen in two isolates from 2009. Virulome analysis showed that IC2 isolates contained genes for capsular polysaccharide KL32 and lipooligosacharide OCL5. A 8.9 Kb plasmid encoding the blaOXA24/40 gene was common in all isolates. The persistance over time of a virulent IC2 clone highlights the need of active surveillance to control its spread.
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Affiliation(s)
- Maitane Aranzamendi
- Respiratory Infection and Antimicrobial Resistance Group, Microbiology Department, Infectious Diseases Area, Biogipuzkoa Health Research Institute, Osakidetza Basque Health Service, Donostialdea Integrated Health Organization, 20014 San Sebastián, Spain; (M.A.); (J.M.M.)
- Acinetobacter baumannii Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940 Leioa, Spain;
| | - Kyriaki Xanthopoulou
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50935 Cologne, Germany; (K.X.); (T.B.); (R.A.d.P.); (K.L.); (H.S.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50935 Cologne, Germany
| | - Sandra Sánchez-Urtaza
- Acinetobacter baumannii Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940 Leioa, Spain;
| | - Tessa Burgwinkel
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50935 Cologne, Germany; (K.X.); (T.B.); (R.A.d.P.); (K.L.); (H.S.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50935 Cologne, Germany
| | - Rocío Arazo del Pino
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50935 Cologne, Germany; (K.X.); (T.B.); (R.A.d.P.); (K.L.); (H.S.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50935 Cologne, Germany
| | - Kai Lucaßen
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50935 Cologne, Germany; (K.X.); (T.B.); (R.A.d.P.); (K.L.); (H.S.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50935 Cologne, Germany
| | - M. Pérez-Vázquez
- National Center of Microbiology, Reference and Research Laboratory for Antibiotic Resistance, ISCIII, Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC), 28220 Madrid, Spain; (M.P.-V.); (J.O.-I.)
| | - Jesús Oteo-Iglesias
- National Center of Microbiology, Reference and Research Laboratory for Antibiotic Resistance, ISCIII, Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC), 28220 Madrid, Spain; (M.P.-V.); (J.O.-I.)
| | - Mercedes Sota
- Clinical Laboratory Management Department, IIS Biodonostia Health Research Institute, University Hospital Donostia, 20014 Donostia, Spain;
| | - Jose María Marimón
- Respiratory Infection and Antimicrobial Resistance Group, Microbiology Department, Infectious Diseases Area, Biogipuzkoa Health Research Institute, Osakidetza Basque Health Service, Donostialdea Integrated Health Organization, 20014 San Sebastián, Spain; (M.A.); (J.M.M.)
| | - Harald Seifert
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50935 Cologne, Germany; (K.X.); (T.B.); (R.A.d.P.); (K.L.); (H.S.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50935 Cologne, Germany
- Institute of Translational Research, CECAD Cluster of Excellence, University of Cologne, 50935, Cologne, Germany
| | - Paul G. Higgins
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50935 Cologne, Germany; (K.X.); (T.B.); (R.A.d.P.); (K.L.); (H.S.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50935 Cologne, Germany
| | - Lucía Gallego
- Acinetobacter baumannii Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940 Leioa, Spain;
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He P, Cao F, Qu Q, Geng H, Yang X, Xu T, Wang R, Jia X, Lu M, Zeng P, Luan G. Host range expansion of Acinetobacter phage vB_Ab4_Hep4 driven by a spontaneous tail tubular mutation. Front Cell Infect Microbiol 2024; 14:1301089. [PMID: 38435308 PMCID: PMC10904470 DOI: 10.3389/fcimb.2024.1301089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 02/01/2024] [Indexed: 03/05/2024] Open
Abstract
Bacteriophages (phages) represent promising alternative treatments against multidrug-resistant Acinetobacter baumannii (MDRAB) infections. The application of phages as antibacterial agents is limited by their generally narrow host ranges, so changing or expanding the host ranges of phages is beneficial for phage therapy. Multiple studies have identified that phage tail fiber protein mediates the recognition and binding to the host as receptor binding protein in phage infection. However, the tail tubular-dependent host specificity of phages has not been studied well. In this study, we isolated and characterized a novel lytic phage, vB_Ab4_Hep4, specifically infecting MDRAB strains. Meanwhile, we identified a spontaneous mutant of the phage, vB_Ab4_Hep4-M, which revealed an expanded host range compared to the wild-type phage. A single mutation of G to C was detected in the gene encoding the phage tail tubular protein B and thus resulted in an aspartate to histidine change. We further demonstrated that the host range expansion of the phage mutant is driven by the spontaneous mutation of guanine to cytosine using expressed tail tubular protein B. Moreover, we established that the bacterial capsule is the receptor for phage Abp4 and Abp4-M by identifying mutant genes in phage-resistant strains. In conclusion, our study provided a detailed description of phage vB_Ab4_Hep4 and revealed the tail tubular-dependent host specificity in A. baumannii phages, which may provide new insights into extending the host ranges of phages by gene-modifying tail tubular proteins.
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Affiliation(s)
- Penggang He
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Feng Cao
- Chengdu Phagetimes Biotech Co. Ltd, Chengdu, Sichuan, China
| | - Qianyu Qu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Huaixin Geng
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Xin Yang
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Tong Xu
- Chengdu Phagetimes Biotech Co. Ltd, Chengdu, Sichuan, China
| | - Rui Wang
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Xu Jia
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Mao Lu
- Department of Dermatovenereology, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, China
| | - Peibin Zeng
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Guangxin Luan
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
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de Oliveira PAA, Baboghlian J, Ramos COA, Mançano ASF, Porcari ADM, Girardello R, Ferraz LFC. Selection and validation of reference genes suitable for gene expression analysis by Reverse Transcription Quantitative real-time PCR in Acinetobacter baumannii. Sci Rep 2024; 14:3830. [PMID: 38360762 PMCID: PMC10869792 DOI: 10.1038/s41598-024-51499-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/05/2024] [Indexed: 02/17/2024] Open
Abstract
Acinetobacter baumannii is a Gram-negative bacterium considered an emerging multi-drug-resistant pathogen. Furthermore, this bacterium can survive in extreme environmental conditions, which makes it a frequent cause of nosocomial infection outbreaks. Gene expression analyses by Reverse Transcription Quantitative real-time PCR (RT-qPCR) depend on a reference gene, also called an endogenous gene, which is used to normalize the generated data and thus ensure an accurate analysis with minimal errors. Currently, gene expression analyses in A. baumannii are compromised, as there are no reports in the literature describing the identification of validated reference genes for use in RT-qPCR analyses. For this reason, we selected twelve candidate reference genes of A. baumannii and assessed their expression profile under different experimental and culture conditions. The expression stability of the candidate genes was evaluated by using statistical algorithms such as BestKeeper, geNorm, NormFinder, Delta CT, and RefFinder, in order to identify the most suitable candidate reference genes for RT-qPCR analyses. The statistical analyses indicated rpoB, rpoD, and fabD genes as the most adequate to ensure accurate normalization of RT-qPCR data in A. baumannii. The accuracy of the proposed reference genes was validated by using them to normalize the expression of the ompA gene, encoding the outer membrane protein A, in A. baumannii sensible and resistant to the antibiotic polymyxin. The present work provides suitable reference genes for precise RT-qPCR data normalization on future gene expression studies with A. baumannii.
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Affiliation(s)
| | - Juliana Baboghlian
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, SP, CEP 12916-900, Brazil
| | | | | | - Andréia de Melo Porcari
- Laboratório Multidisciplinar de Pesquisa, Universidade São Francisco, Bragança Paulista, SP, CEP 12916-900, Brazil
| | - Raquel Girardello
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, SP, CEP 12916-900, Brazil
| | - Lúcio Fábio Caldas Ferraz
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, SP, CEP 12916-900, Brazil.
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Sabour S, Bantle K, Bhatnagar A, Huang JY, Biggs A, Bodnar J, Dale JL, Gleason R, Klein L, Lasure M, Lee R, Nazarian E, Schneider E, Smith L, Snippes Vagnone P, Therrien M, Tran M, Valley A, Wang C, Young EL, Lutgring JD, Brown AC. Descriptive analysis of targeted carbapenemase genes and antibiotic susceptibility profiles among carbapenem-resistant Acinetobacter baumannii tested in the Antimicrobial Resistance Laboratory Network-United States, 2017-2020. Microbiol Spectr 2024; 12:e0282823. [PMID: 38174931 PMCID: PMC10845962 DOI: 10.1128/spectrum.02828-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/16/2023] [Indexed: 01/05/2024] Open
Abstract
Acinetobacter baumannii is a Gram-negative bacillus that can cause severe and difficult-to-treat healthcare-associated infections. A. baumannii can harbor mobile genetic elements carrying genes that produce carbapenemase enzymes, further limiting therapeutic options for infections. In the United States, the Antimicrobial Resistance Laboratory Network (AR Lab Network) conducts sentinel surveillance of carbapenem-resistant Acinetobacter baumannii (CRAB). Participating clinical laboratories sent CRAB isolates to the AR Lab Network for characterization, including antimicrobial susceptibility testing and molecular detection of class A (Klebsiella pneumoniae carbapenemase), class B (Active-on-Imipenem, New Delhi metallo-β-lactamase, and Verona integron-encoded metallo-β-lactamase), and class D (Oxacillinase, blaOXA-23-like, blaOXA-24/40-like, blaOXA-48-like, and blaOXA-58-like) carbapenemase genes. During 2017‒2020, 6,026 CRAB isolates from 45 states were tested for targeted carbapenemase genes; 1% (64 of 5,481) of CRAB tested for targeted class A and class B genes were positive, but 83% (3,351 of 4,041) of CRAB tested for targeted class D genes were positive. The number of CRAB isolates carrying a class A or B gene increased from 2 of 312 (<1%) tested in 2017 to 26 of 1,708 (2%) tested in 2020. Eighty-three percent (2,355 of 2,846) of CRAB with at least one of the targeted carbapenemase genes and 54% (271 of 500) of CRAB without were categorized as extensively drug resistant; 95% (42 of 44) of isolates carrying more than one targeted gene had difficult-to-treat susceptibility profiles. CRAB isolates carrying targeted carbapenemase genes present an emerging public health threat in the United States, and their rapid detection is crucial to improving patient safety.IMPORTANCEThe Centers for Disease Control and Prevention has classified CRAB as an urgent public health threat. In this paper, we used a collection of >6,000 contemporary clinical isolates to evaluate the phenotypic and genotypic properties of CRAB detected in the United States. We describe the frequency of specific carbapenemase genes detected, antimicrobial susceptibility profiles, and the distribution of CRAB isolates categorized as multidrug resistant, extensively drug-resistant, or difficult to treat. We further discuss the proportion of isolates showing susceptibility to Food and Drug Administration-approved agents. Of note, 84% of CRAB tested harbored at least one class A, B, or D carbapenemase genes targeted for detection and 83% of these carbapenemase gene-positive CRAB were categorized as extensively drug resistant. Fifty-four percent of CRAB isolates without any of these carbapenemase genes detected were still extensively drug-resistant, indicating that infections caused by CRAB are highly resistant and pose a significant risk to patient safety regardless of the presence of one of these carbapenemase genes.
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Affiliation(s)
- Sarah Sabour
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Katie Bantle
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Amelia Bhatnagar
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jennifer Y. Huang
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Angela Biggs
- Maryland Department of Health, Baltimore, Maryland, USA
| | | | | | - Rachel Gleason
- Tennessee Department of Health, Nashville, Tennessee, USA
| | - Liore Klein
- Maryland Department of Health, Baltimore, Maryland, USA
| | - Megan Lasure
- Wisconsin State Laboratory of Hygiene, Madison, Wisconsin, USA
| | - Rachel Lee
- Texas Department of State Health Services, Austin, Texas, USA
| | | | - Emily Schneider
- Washington State Department of Health Public Health Laboratories, Shoreline, Washington, USA
| | - Lori Smith
- Utah Public Health Laboratory, Taylorsville, Utah, USA
| | | | | | - Michael Tran
- Washington State Department of Health Public Health Laboratories, Shoreline, Washington, USA
| | - Ann Valley
- Wisconsin State Laboratory of Hygiene, Madison, Wisconsin, USA
| | - Chun Wang
- Texas Department of State Health Services, Austin, Texas, USA
| | - Erin L. Young
- Utah Public Health Laboratory, Taylorsville, Utah, USA
| | - Joseph D. Lutgring
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Allison C. Brown
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Mushtaq F, Nadeem A, Yabrag A, Bala A, Karah N, Zlatkov N, Nyunt Wai S, Uhlin BE, Ahmad I. Colony phase variation switch modulates antimicrobial tolerance and biofilm formation in Acinetobacter baumannii. Microbiol Spectr 2024; 12:e0295623. [PMID: 38205963 PMCID: PMC10845969 DOI: 10.1128/spectrum.02956-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/09/2023] [Indexed: 01/12/2024] Open
Abstract
Carbapenem-resistant Acinetobacter baumannii causes one of the most difficult-to-treat nosocomial infections. Polycationic drugs like polymyxin B or colistin and tetracycline drugs such as doxycycline or minocycline are commonly used to treat infections caused by carbapenem-resistant A. baumannii. Here, we show that a subpopulation of cells associated with the opaque/translucent colony phase variation by A. baumannii AB5075 displays differential tolerance to subinhibitory concentrations of colistin and tetracycline. Using a variety of microscopic techniques, we demonstrate that extracellular polysaccharide moieties mediate colistin tolerance to opaque A. baumannii at single-cell level and that mushroom-shaped biofilm structures protect opaque bacteria at the community level. The colony switch phenotype is found to alter several traits of A. baumannii, including long-term survival under desiccation, tolerance to ethanol, competition with Escherichia coli, and intracellular survival in the environmental model host Acanthamoeba castellanii. Additionally, our findings suggest that extracellular DNA associated with membrane vesicles can promote colony switching in a DNA recombinase-dependent manner.IMPORTANCEAs a WHO top-priority drug-resistant microbe, Acinetobacter baumannii significantly contributes to hospital-associated infections worldwide. One particularly intriguing aspect is its ability to reversibly switch its colony morphotype on agar plates, which has been remarkably underexplored. In this study, we employed various microscopic techniques and phenotypic assays to investigate the colony phase variation switch under different clinically and environmentally relevant conditions. Our findings reveal that the presence of a poly N-acetylglucosamine-positive extracellular matrix layer contributes to the protection of bacteria from the bactericidal effects of colistin. Furthermore, we provide intriguing insights into the multicellular lifestyle of A. baumannii, specifically in the context of colony switch variation within its predatory host, Acanthamoeba castellanii.
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Affiliation(s)
- Fizza Mushtaq
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- Institute of Biomedical and Allied Health Sciences, University of Health Sciences, Lahore, Pakistan
| | - Aftab Nadeem
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Abdelbasset Yabrag
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Anju Bala
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Nabil Karah
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Nikola Zlatkov
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Sun Nyunt Wai
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Bernt Eric Uhlin
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Irfan Ahmad
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- Institute of Biomedical and Allied Health Sciences, University of Health Sciences, Lahore, Pakistan
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
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Yousefi Nojookambari N, Eslami G, Sadredinamin M, Vaezjalali M, Nikmanesh B, Dehbanipour R, Yazdansetad S, Ghalavand Z. Sub-minimum inhibitory concentrations (sub-MICs) of colistin on Acinetobacter baumannii biofilm formation potency, adherence, and invasion to epithelial host cells: an experimental study in an Iranian children's referral hospital. Microbiol Spectr 2024; 12:e0252323. [PMID: 38230925 PMCID: PMC10846280 DOI: 10.1128/spectrum.02523-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 11/07/2023] [Indexed: 01/18/2024] Open
Abstract
Here, we described the efficacy of colistin sub-minimum inhibitory concentrations (sub-MICs) on biofilm-forming activity, host epithelial cell adherence, and invasion capacity of Acinetobacter baumannii strains collected from children admitted to the Children's Medical Center Hospital. Biofilm formation potency of A. baumannii clinical isolates was measured using a 96-well microtiter plate assay. Distribution of biofilm-related genes, including bap, abaI, ompA, csuE, and blaPER-1, was detected by PCR. The mRNA expression level of ompA and csuE was measured by qPCR in the presence of ¼ and ½ MICs of colistin. A. baumannii adhesion and invasion to eukaryotic host cells were phenotypically assayed at sub-MICs of colistin. Eighty percent (56/70) and 35.7% (25/70) of A. baumannii isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR) phenotypes, respectively. The strong, moderate, and weak biofilm producers of A. baumannii were 37.1% (26/70), 32.8%, (23/70), and 22.8% (16/70), respectively. The frequencies of biofilm-associated genes were 100% for abaI, ompA, and csuE, followed by 22.8% (16/70) and 24.3% (17/70) for bap and blaPER-1, respectively. The downregulation of csuE and ompA expression levels was observed in the sub-MIC of colistin. In vitro cell culture study showed a decreased capability of A. baumannii to adhere to the human epithelial cells at sub-inhibitory doses of colistin; however, none of the isolates could invade HEp-2 cells. Our study showed that the genes encoding biofilm-associated proteins undergo downregulation in expression levels after exposure to sub-MICs of colistin in A. baumannii. Longitudinal in vivo studies are needed to fully understand the clinical aspects of pathogenicity mechanisms and evolutionary dynamics of drug resistance.IMPORTANCESince the toxicity of colistin is dose dependent, there is a focus on strategies that reduce the dose while maintaining the therapeutic effect of the drug. Our findings about sub-inhibitory doses of colistin provide a novel insight into the logical use of colistin to treat and control Acinetobacter baumannii-related infections in clinical practice.
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Affiliation(s)
- Neda Yousefi Nojookambari
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Gita Eslami
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehrzad Sadredinamin
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Vaezjalali
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Bahram Nikmanesh
- Department of Medical Laboratory Sciences, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran
| | - Razieh Dehbanipour
- Department of Microbiology, School of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Sajjad Yazdansetad
- Infectious Diseases Research Center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Zohreh Ghalavand
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Vijayakumar S, Swetha RG, Bakthavatchalam YD, Vasudevan K, Abirami Shankar B, Kirubananthan A, Walia K, Ramaiah S, Biswas I, Veeraraghavan B, Anbarasu A. Genomic investigation unveils colistin resistance mechanism in carbapenem-resistant Acinetobacter baumannii clinical isolates. Microbiol Spectr 2024; 12:e0251123. [PMID: 38214512 PMCID: PMC10846133 DOI: 10.1128/spectrum.02511-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024] Open
Abstract
Colistin resistance in Acinetobacter baumannii is mediated by multiple mechanisms. Recently, mutations within pmrABC two-component system and overexpression of eptA gene due to upstream insertion of ISAba1 have been shown to play a major role. Thus, the aim of our study is to characterize colistin resistance mechanisms among the clinical isolates of A. baumannii in India. A total of 207 clinical isolates of A. baumannii collected from 2016 to 2019 were included in this study. Mutations within lipid A biosynthesis and pmrABC genes were characterized by whole-genome shotgun sequencing. Twenty-eight complete genomes were further characterized by hybrid assembly approach to study insertional inactivation of lpx genes and the association of ISAba1-eptA. Several single point mutations (SNPs), like M12I in pmrA, A138T and A444V in pmrB, and E117K in lpxD, were identified. We are the first to report two novel SNPs (T7I and V383I) in the pmrC gene. Among the five colistin-resistant A. baumannii isolates where complete genome was available, the analysis showed that three of the five isolates had ISAba1 insertion upstream of eptA. No mcr genes were identified among the isolates. We mapped the SNPs on the respective protein structures to understand the effect on the protein activity. We found that majority of the SNPs had little effect on the putative protein function; however, some SNPs might destabilize the local structure. Our study highlights the diversity of colistin resistance mechanisms occurring in A. baumannii, and ISAba1-driven eptA overexpression is responsible for colistin resistance among the Indian isolates.IMPORTANCEAcinetobacter baumannii is a Gram-negative, emerging and opportunistic bacterial pathogen that is often associated with a wide range of nosocomial infections. The treatment of these infections is hindered by increase in the occurrence of A. baumannii strains that are resistant to most of the existing antibiotics. The current drug of choice to treat the infection caused by A. baumannii is colistin, but unfortunately, the bacteria started to show resistance to the last-resort antibiotic. The loss of lipopolysaccharides and mutations in lipid A biosynthesis genes are the main reasons for the colistin resistance. The present study characterized 207 A. baumannii clinical isolates and constructed complete genomes of 28 isolates to recognize the mechanisms of colistin resistance. We showed the mutations in the colistin-resistant variants within genes essential for lipid A biosynthesis and that cause these isolates to lose the ability to produce lipopolysaccharides.
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Affiliation(s)
- Saranya Vijayakumar
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Rayapadi G. Swetha
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, India
| | | | - Karthick Vasudevan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
- Department of Biotechnology, School of Applied Sciences, REVA University, Bangalore, India
| | - Baby Abirami Shankar
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Kamini Walia
- Division of Epidemiology and Communicable Diseases, Indian Council for Medical Research, New Delhi, India
| | - Sudha Ramaiah
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, India
| | - Indranil Biswas
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas, USA
| | - Balaji Veeraraghavan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Anand Anbarasu
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, India
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Duan Z, Li X, Li S, Zhou H, Hu L, Xia H, Xie L, Xie F. Nosocomial surveillance of multidrug-resistant Acinetobacter baumannii: a genomic epidemiological study. Microbiol Spectr 2024; 12:e0220723. [PMID: 38197661 PMCID: PMC10846281 DOI: 10.1128/spectrum.02207-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 12/14/2023] [Indexed: 01/11/2024] Open
Abstract
Acinetobacter baumannii is a major opportunistic pathogen causing hospital-acquired infections, and it is imperative to comprehend its evolutionary and epidemiological dynamics in hospitals to prevent and control nosocomial transmission. Here, we present a comprehensive genomic epidemiological study involving the genomic sequencing and antibiotic resistance profiling of 634 A. baumannii strains isolated from seven intensive care units (ICUs) of a Chinese general hospital over 2 consecutive years. Our study reveals that ST2 is highly dominant (90.54%) in the ICUs, with 98.90% of the ST2 exhibiting multidrug resistant or extensively drug resistant. Phylogenetic analyses of newly sequenced genomes and public data suggest that nosocomial isolates originated outside the hospital but evolved inside. The major lineages appear to be stable, with 9 of the 28 identified nosocomial epidemic clones infecting over 60% of the affected patients. However, outbreaks of two highly evolved clones have been observed in different hospitals, suggesting significant inter-hospital transmission chains. By coupling patient medical records and genomic divergence of the ST2, we found that cross-ward patient transfer played a crucial role in pathogen's nosocomial transmission. Additionally, we identified 831 potential adaptive evolutionary loci and 44 associated genes by grouping and comparing the genomes of clones with different prevalence. Overall, our study provides a comprehensive and contemporary survey on the epidemiology and genomic evolution of A. baumannii in a large Chinese general hospital. These findings shed light on the nosocomial evolution and transmission of A. baumannii and offers valuable information for transmission prevention and antibiotic therapy.IMPORTANCEThis study delved into the genomic evolution and transmission of nosocomial Acinetobacter baumannii on a large scale, spanning both an extended time period and the largest sample size to date. Through molecular epidemiological investigations based on genomics, we can directly trace the origin of the pathogen, detecting and monitoring outbreaks of infectious diseases in a timely manner, and ensuring public health safety. In addition, this study also collects a large amount of genomic and antibiotic resistance detection data, which is helpful for phenotype prediction based on genomic sequencing. It enables patients to receive personalized antibiotic treatment quickly, helps doctors select antibiotics more accurately, and contributes to reducing the use of antibiotics and lowering the risk of antibiotic resistance development.
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Affiliation(s)
- Zhimei Duan
- College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing, China
| | - Xuming Li
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Song Li
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Hui Zhou
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Long Hu
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Han Xia
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Lixin Xie
- College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing, China
| | - Fei Xie
- College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing, China
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Liu C, Liu J, Lu Q, Wang P, Zou Q. The Mechanism of Tigecycline Resistance in Acinetobacter baumannii under Sub-Minimal Inhibitory Concentrations of Tigecycline. Int J Mol Sci 2024; 25:1819. [PMID: 38339095 PMCID: PMC10855123 DOI: 10.3390/ijms25031819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
The presence of sub-minimal inhibitory concentration (sub-MIC) antibiotics in our environment is widespread, and their ability to induce antibiotic resistance is inevitable. Acinetobacter baumannii, a pathogen known for its strong ability to acquire antibiotic resistance, has recently shown clinical resistance to the last-line antibiotic tigecycline. To unravel the complex mechanism of A. baumannii drug resistance, we subjected tigecycline-susceptible, -intermediate, and -mildly-resistant strains to successive increases in sub-MIC tigecycline and ultimately obtained tigecycline-resistant strains. The proteome of both key intermediate and final strains during the selection process was analyzed using nanoLC-MS/MS. Among the more than 2600 proteins detected in all strains, we found that RND efflux pump AdeABC was associated with the adaptability of A. baumannii to tigecycline under sub-MIC pressure. qRT-PCR analysis also revealed higher expression of AdeAB in strains that can quickly acquire tigecycline resistance compared with strains that displayed lower adaptability. To validate our findings, we added an efflux pump inhibitor, carbonyl cyanide m-chlorophenyl hydrazine (CCCP), to the medium and observed its ability to inhibit tigecycline resistance in A. baumannii strains with quick adaptability. This study contributes to a better understanding of the mechanisms underlying tigecycline resistance in A. baumannii under sub-MIC pressure.
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Affiliation(s)
| | | | | | | | - Qinghua Zou
- Department of Microbiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.L.); (J.L.); (Q.L.); (P.W.)
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König P, Averhoff B, Müller V. K + homeostasis is important for survival of Acinetobacter baumannii ATCC 19606 in the nosocomial environment. Int Microbiol 2024; 27:303-310. [PMID: 37338636 PMCID: PMC10830791 DOI: 10.1007/s10123-023-00389-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/24/2023] [Accepted: 06/05/2023] [Indexed: 06/21/2023]
Abstract
Pathogenic bacteria have developed several mechanisms to thrive within the hostile environment of the human host, but it is often disregarded that their survival outside this niche is crucial for their successful transmission. Acinetobacter baumannii is very well adapted to both the human host and the hospital environment. The latter is facilitated by multifactorial mechanisms including its outstanding ability to survive on dry surfaces, its high metabolic diversity, and, of course, its remarkable osmotic resistance. As a first response to changing osmolarities, bacteria accumulate K+ in high amount to counterbalance the external ionic strength. Here, we addressed whether K+ uptake is involved in the challenges imposed by the harsh conditions outside its host and how K+ import influences the antibiotic resistance of A. baumannii. For this purpose, we used a strain lacking all major K+ importer ∆kup∆trk∆kdp. Survival of this mutant was strongly impaired under nutrient limitation in comparison to the wild type. Furthermore, we found that not only the resistance against copper but also against the disinfectant chlorhexidine was reduced in the triple mutant compared to the wild type. Finally, we revealed that the triple mutant is highly susceptible to a broad range of antibiotics and antimicrobial peptides. By studying mutants, in which the K+ transporter were deleted individually, we provide evidence that this effect is a consequence of the altered K+ uptake machinery. Conclusively, this study provides supporting information on the relevance of K+ homeostasis in the adaptation of A. baumannii to the nosocomial environment.
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Affiliation(s)
- Patricia König
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany
| | - Beate Averhoff
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany.
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Kamani J, Nachum-Biala Y, Bukar L, Shand M, Harrus S. Molecular detection of Bartonella quintana, Acinetobacter baumannii and Acinetobacter haemolyticus in Pediculus humanus lice in Nigeria, West Africa. Zoonoses Public Health 2024; 71:48-59. [PMID: 37787179 DOI: 10.1111/zph.13082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/18/2023] [Accepted: 09/11/2023] [Indexed: 10/04/2023]
Abstract
The human lice Pediculus humanus is distributed worldwide but, it thrives and flourishes under conflict situations where people are forced to live in crowded unhygienic conditions. Molecular methods were used to identify and screen human lice for the DNA of pathogens of public health importance in an area that has been under insurgency related to religious and political conflicts with tens of thousands of internally displaced people (IDP). DNA of Bartonella quintana, Acinetobacter baumannii and Acinetobacter haemolyticus was detected in 18.3%, 40.0% and 1.7%, respectively, of human lice collected from children in Maiduguri, Nigeria. More body lice than head lice were positive for pathogen's DNA (64.3% vs. 44.4%; χ2 = 1.3, p = 0.33), but the difference was not significant. Two lice samples were found to harbour mixed DNA of B. quintana and A. baumannii. Phylogenetic analysis of the cytochrome b (cytb) gene sequences of the positive lice specimens placed them into clades A and E. This is the first report on the molecular identification of human lice and the detection of the DNA of pathogens of public health importance in lice in Nigeria, West Africa. The findings of this study will assist policy makers and medical practitioners in formulating a holistic healthcare delivery to IDPs.
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Affiliation(s)
- Joshua Kamani
- National Veterinary Research Institute (NVRI), Vom, Plateau State, Nigeria
| | - Yaarit Nachum-Biala
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Laminu Bukar
- National Veterinary Research Institute (NVRI), Vom, Plateau State, Nigeria
| | - Mike Shand
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow, UK
| | - Shimon Harrus
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
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Nishida S, Ono Y. Genomic analysis of extensively drug-resistant Acinetobacter baumannii harbouring a conjugative plasmid containing aminoglycoside resistance transposon TnaphA6. J Infect Public Health 2024; 17:293-298. [PMID: 38150808 DOI: 10.1016/j.jiph.2023.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 11/14/2023] [Accepted: 12/04/2023] [Indexed: 12/29/2023] Open
Abstract
The occurrence of multidrug-resistant Acinetobacter baumannii (MDRA) has increased rapidly and is associated with severe nosocomial infections. MDRA has emerged in the hospital setting and has evolved into extensively drug-resistant A. baumannii (XDRA). A clinical XDRA isolate obtained from a hospitalised patient in 2016 was evaluated for antibiotic susceptibility and whole-genome sequence. The XDRA isolate was resistant to β-lactams, including broad-spectrum cephalosporins and carbapenems, and to aminoglycosides, fosfomycin, fluoroquinolones, tetracyclines, tigecycline, and trimethoprim-sulfamethoxazole. The isolate harboured abaF, ant(3″)-II-c, aph(3″)-Ib, aph(6)-Id, armA, blaADC-73, blaTEM-1, blaOXA-66, blaOXA-23, mphE, msrE and tet(B). Quinolone resistance was associated with mutations gyrA S81L and parC S84L. Tigecycline resistance was associated with a mutation in adeS. The isolate belonged to Oxford and Pasteur scheme sequence type 1050 and 2, respectively, and harboured a conjugative plasmid containing the aminoglycoside resistance transposon TnaphA6. Our study demonstrates that the isolate is closely related to a recent MDRA identified in Australia and the USA, in which a similar conjugative plasmid is not observed. Although the MDRA in Australia caused an outbreak, our hospital's surveillance protocol managed to prevent a further outbreak. Our finding suggests that this XDRA isolate is of concern in hospital and community care settings. The gpi allele could be a marker for discriminating this isolate from clonal complex 92 isolates.
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Affiliation(s)
- Satoshi Nishida
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Itabashi, Tokyo, Japan.
| | - Yasuo Ono
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Itabashi, Tokyo, Japan; Faculty of Health and Medical Science, Teikyo Heisei University, Toshima, Tokyo, Japan
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Pos KM. RND multidrug efflux transporters: similar appearances, diverse actions. J Bacteriol 2024; 206:e0040323. [PMID: 38084964 PMCID: PMC10810212 DOI: 10.1128/jb.00403-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
In a recent study by Inga V. Leus, Sean R. Roberts, Anhthu Trinh, Edward W. Yu, and Helen I. Zgurskaya (J Bacteriol, 2023, https://doi.org/10.1128/jb.00217-23), it was found that the clinically relevant resistance-nodulation-cell division (RND)-type AdeABC antibiotic efflux pump from Acinetobacter baumannii exhibits close communication between its antibiotic binding sites. Alterations in one of them can have far-reaching impacts on the drug translocation pathway. These insights could reshape our understanding of RND-type efflux pump mechanisms.
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Affiliation(s)
- Klaas Martinus Pos
- Institute of Biochemistry, Goethe-University Frankfurt, Frankfurt, Germany
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Leus IV, Roberts SR, Trinh A, W. Yu E, Zgurskaya HI. Nonadditive functional interactions between ligand-binding sites of the multidrug efflux pump AdeB from Acinetobacter baumannii. J Bacteriol 2024; 206:e0021723. [PMID: 37850798 PMCID: PMC10809976 DOI: 10.1128/jb.00217-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/12/2023] [Indexed: 10/19/2023] Open
Abstract
Multidrug efflux is one of the major mechanisms of antibiotic resistance identified in clinical isolates of the human pathogen Acinetobacter baumannii. The multiple antibiotic resistance in this species is often enabled by the overproduction of the tripartite efflux pump AdeABC. In this pump, AdeB is the inner membrane transporter from the resistance-nodulation-division (RND) superfamily of proteins, which is responsible for the recognition and efflux of multiple structurally unrelated compounds. Like other RND transporters, AdeB is a trimeric protein with ligand-binding sites located in the large periplasmic domains. Previous structural studies, however, highlighted the uniqueness of AdeB interactions with ligands. Up to three ligand molecules were bound to one protomer of AdeB, mapping its substrate translocation path. In this study, we introduced single and double substitutions in the identified ligand-binding sites of AdeB. Our results show that the mechanism of substrate translocation by AdeB is different from that of other characterized RND transporters and that the functional interactions between the sites are nonadditive. We identified AdeB mutants with both the loss and the gain of antibiotic susceptibility phenotypes, as well as AdeB mutations making A. baumannii cells overproducing such pump variants even more susceptible to multiple antibiotics than efflux-deficient cells. IMPORTANCE Multidrug efflux pumps of the resistance-nodulation-division superfamily of proteins are important contributors to various aspects of bacterial physiology and antibiotic resistance. Studies of the best-characterized model transporter AcrB from Escherichia coli suggested that these transporters operate by a functional rotation mechanism in which various substrates bind to at least two different binding sites. This study suggests that the mechanism of AdeB is distinct and that the binding sites in this transporter are functionally linked.
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Affiliation(s)
- Inga V. Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Sean R. Roberts
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Anhthu Trinh
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
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Zhao S, Zhang B, Liu C, Sun X, Chu Y. Acinetobacter baumannii infection in intensive care unit: analysis of distribution and drug resistance. Mol Biol Rep 2024; 51:120. [PMID: 38227070 DOI: 10.1007/s11033-023-09144-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 12/12/2023] [Indexed: 01/17/2024]
Abstract
BACKGROUND The isolation rate and drug resistance rate of Acinetobacter baumannii (A.baumannii) have increased over the years, which has become one of the main causes of infection and death in intensive care unit (ICU) patients. Analysis of the distribution characteristics, drug resistance and influencing factors of A.baumannii in ICU could provide basis and reference for the infection prevention and clinical treatment. METHODS AND RESULTS In this study, patients diagnosed with A.baumannii infection in ICU from January 2020 to December 2021 were selected. Samples of patients were collected for bacterial culture, drug sensitivity test analysis and drug resistant gene detection of A.baumannii. A total of 197 strains of A.baumannii were cultured in 2021, which was 18 strains more than in 2020. The specimens were mainly from lower respiratory tract secretions, and the isolated strains were multi-drug resistant. The resistance of isolates to tobramycin, gentamicin, and trimethoprim-sulfamethoxazole in 2021 showed a significant increase compared to 2020, while there were no significant differences observed in other resistance changes. The prevalence of multi-drug resistant A.baumannii in ICU remains high. Among them, all imipenem-resistant A.baumannii strains carried OXA-23 gene. CONCLUSION Clinical treatment should use antibiotics reasonably based on the characteristics of bacterial resistance, and strengthen the prevention and control of hospital infection, pay more attention to the disinfection and isolation to reduce the risk of cross infection.
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Affiliation(s)
- Siyang Zhao
- Department of Clinical Research Center, Dazhou Central Hospital, Dazhou, Sichuan province, China
| | - Bing Zhang
- Department of Clinical Pharmacy, Dazhou Central Hospital, Dazhou, Sichuan province, China
| | - Conghai Liu
- Department of Clinical Pharmacy, Dazhou Central Hospital, Dazhou, Sichuan province, China
| | - Xiaodong Sun
- Department of Clinical Pharmacy, Dazhou Central Hospital, Dazhou, Sichuan province, China
| | - Yanpeng Chu
- Department of Clinical Research Center, Dazhou Central Hospital, Dazhou, Sichuan province, China.
- College of Health Care Industry, Sichuan University of Arts and Science, No.56 nanyuemiao Street, Tongchuan District, Dazhou, Sichuan province, China.
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Pérez-Varela M, Singh R, Colquhoun JM, Starich OG, Tierney ARP, Tipton KA, Rather PN. Evidence for Rho-dependent control of a virulence switch in Acinetobacter baumannii. mBio 2024; 15:e0270823. [PMID: 38085026 PMCID: PMC10790780 DOI: 10.1128/mbio.02708-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 10/26/2023] [Indexed: 12/31/2023] Open
Abstract
IMPORTANCE Acinetobacter baumannii is a significant cause of infections in the healthcare setting. More recently, A. baumannii has been a leading cause of secondary bacterial pneumonia in patients infected with SARS-CoV-2 and the overall frequency of A. baumannii infection increased 78% during the COVID-19 pandemic. A. baumannii can exist in virulent or avirulent subpopulations and this interconversion is mediated by the expression of a family of TetR-type transcriptional regulators. In this study, we demonstrate that Rho is a key regulatory component in the expression of these TetR regulators. Overall, this study is the first to address a role for Rho in A. baumannii and provides additional evidence for the role of Rho in regulating diversity in bacterial subpopulations.
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Affiliation(s)
- María Pérez-Varela
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
| | - Raja Singh
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
| | - Jennifer M. Colquhoun
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
- Research Service, Atlanta VA Medical Center, Decatur, Georgia, USA
| | - Olivia G. Starich
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
| | - Aimee R. P. Tierney
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
| | - Kyle A. Tipton
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
| | - Philip N. Rather
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
- Research Service, Atlanta VA Medical Center, Decatur, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University, Atlanta, Georgia, USA
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50
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Cook D, Flannigan MD, Chariker JH, Hare JM. DNA damage response coregulator ddrR affects many cellular pathways and processes in Acinetobacter baumannii 17978. Front Cell Infect Microbiol 2024; 13:1324091. [PMID: 38274737 PMCID: PMC10808703 DOI: 10.3389/fcimb.2023.1324091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 12/20/2023] [Indexed: 01/27/2024] Open
Abstract
Introduction Acinetobacter baumannii strain 17978 is an opportunistic pathogen possessing a DNA damage response (DDR) in which multiple error-prone polymerase genes are co-repressed by a UmuD homolog, UmuDAb, and the small Acinetobacter-specific protein DdrR. Additionally, these regulators coactivate nine other genes. We identified the DNA damage-inducible transcriptome for wildtype, umuDAb, and recA strains, and later established the ddrR DDR transcriptome. However, the ATCC 17978 reference genome had several assembly errors and lacked the 44 kb virulence locus, AbaAL44, that is present in the strain 17978 UN. Methods For this project, we combined our earlier single-end read RNAseq data with the ddrR paired-end reads and aligned these data to the improved 17978 UN genome assembly that resembled our laboratory strain, 17978 JH. Results New DESeq2 analyses verified previous differentially expressed genes (DEGs) but also found 339 genes in 17978 JH that were not annotated or physically present in the older genome assembly. Sixty-three were differentially expressed after DNA damage, and 182 had differential basal expression when comparing umuDAb, ddrR, or recA strains to wildtype, with 94 genes' expression unchanged. This work identified and characterized the 55 gene DNA damage-repressible transcriptome, 98% of which required either umuDAb or ddrR for repression. Two-thirds of these DEGs required both regulators. We also identified 110 genes repressed only in the ddrR strain, ~50% of which were due to increased basal expression levels. Basal gene expression in the ddrR mutant was further dysregulated independent of the DDR. Over 800 genes were upregulated, and over 1200 genes were downregulated compared to wildtype expression. Half of A. baumannii's essential genes were upregulated in the ddrR strain, including cell division genes, and two-thirds of these were downregulated in the umuDAb strain. Discussion The ddrR mutant upregulated genes enriched in translation, RNA metabolism, protein metabolism, AA/FA/cell-structure synthesis, and transport, while downregulating genes enriched in quorum sensing, biofilm production, secretion systems, pilus production, cell adhesion, and aromatics and chlorine degradation. Our data underscore the need for accurate and appropriately matched genome assemblies and indicate that ddrR affects approximately 60% of the genome, rendering it a potential target for Acinetobacter baumannii infection treatment.
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Affiliation(s)
- Deborah Cook
- Department of Biology and Chemistry, Morehead State University, Morehead, KY, United States
| | - Mollee D. Flannigan
- Department of Biology and Chemistry, Morehead State University, Morehead, KY, United States
| | - Julia H. Chariker
- Kentucky IDeA Networks of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, KY, United States
| | - Janelle M. Hare
- Department of Biology and Chemistry, Morehead State University, Morehead, KY, United States
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