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Fan J, Cui H, Mu Z, Yao C, Yang M, Jin Y, Ning C, Zhang H. Non-targeted metabolomics analysis of fermented traditional Chinese medicine and its impact on growth performance, serum biochemistry, and intestinal microbiome of weaned lambs. Sci Rep 2024; 14:20385. [PMID: 39223216 PMCID: PMC11369253 DOI: 10.1038/s41598-024-71516-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 08/28/2024] [Indexed: 09/04/2024] Open
Abstract
Fermented traditional Chinese medicines (TCMs) have been identified as a low-cost and promising feed additive to to alleviate weaning stress in young livestock and poultry effectively. This study investigated the impact of probiotic fermentation on the metabolite content of BanQi (Radix Isatidis and Astragalus membranaceus) extract while also examined the effects of both fermented-BanQi (FBQ) and unfermented-BanQi (UBQ) on growth performance, serum biochemistry, intestinal villi, and gut microbiota in weaned lambs. This study demonstrated that compared with UBQ, FBQ contained significantly higher levels of free amino acids (e.g., phenylalanine and isoleucine), short peptides (e.g., Val-Leu-Pro-Val-Pro-Gln and Gly-Leu), and the active ingredients (e.g., vindesine and reserpine) (P < 0.05). The addition of FBQ to the diet significantly increased the final body weight and average daily gain of weaned lambs (P < 0.05). In addition, FBQ significantly increased the total protein level in the serum and the villus length of the jejunum and ileum in lambs, while significantly reduced the levels of aspartate aminotransferase (AST) and urea (P < 0.05). Sequencing of the intestinal flora showed that FBQ improved the diversity of intestinal flora and promoted the enrichment of beneficial bacteria in the lamb intestine, such as Mogibacterium and Butyrivibrio, compared to NC or UBQ groups (P < 0.05). Fermentation with Bacillus subtilis can enhance the content of free amino acids, peptides, and active ingredients in BanQi extract, making it an effective method to improve the efficacy of traditional Chinese medicine. Adding FBQ to the diet can improve the growth performance of weaned lambs, and its mechanism may be related to increasing the height of intestinal villi and increasing the diversity of intestinal flora.
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Affiliation(s)
- Junyang Fan
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Henan Agricultural University, Zhengzhou, 450002, China
| | - Hongyan Cui
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China
| | - Zhiying Mu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China
| | - Chunxiao Yao
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China
| | - Mingfan Yang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China
- Key Laboratory for Animal-Derived Food Safety of Henan Province, Zhengzhou, 450002, China
- Key Laboratory for Study and Evaluation of Chinese Veterinary Medicine, Zhengzhou, 450002, China
| | - Yue Jin
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China
| | - Changshen Ning
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China
| | - Hongying Zhang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China.
- Key Laboratory for Animal-Derived Food Safety of Henan Province, Zhengzhou, 450002, China.
- Key Laboratory for Study and Evaluation of Chinese Veterinary Medicine, Zhengzhou, 450002, China.
- Ministry of Education Key Laboratory for Animal Pathogens and Biosafety, Henan Agricultural University, Zhengzhou, 450002, China.
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Sivalingam P, Sabatino R, Sbaffi T, Corno G, Fontaneto D, Borgomaneiro G, Rogora M, Crotti E, Mapelli F, Borin S, Pilar AL, Eckert EM, Di Cesare A. Anthropogenic pollution may enhance natural transformation in water, favouring the spread of antibiotic resistance genes. JOURNAL OF HAZARDOUS MATERIALS 2024; 475:134885. [PMID: 38876022 DOI: 10.1016/j.jhazmat.2024.134885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/19/2024] [Accepted: 06/10/2024] [Indexed: 06/16/2024]
Abstract
Aquatic ecosystems are crucial in the antimicrobial resistance cycle. While intracellular DNA has been extensively studied to understand human activity's impact on antimicrobial resistance gene (ARG) dissemination, extracellular DNA is frequently overlooked. This study examines the effect of anthropogenic water pollution on microbial community diversity, the resistome, and ARG dissemination. We analyzed intracellular and extracellular DNA from wastewater treatment plant effluents and lake surface water by shotgun sequencing. We also conducted experiments to evaluate anthropogenic pollution's effect on transforming extracellular DNA (using Gfp-plasmids carrying ARGs) within a natural microbial community. Chemical analysis showed treated wastewater had higher anthropogenic pollution-related parameters than lake water. The richness of microbial community, antimicrobial resistome, and high-risk ARGs was greater in treated wastewaters than in lake waters both for intracellular and extracellular DNA. Except for the high-risk ARGs, richness was significantly higher in intracellular than in extracellular DNA. Several ARGs were associated with mobile genetic elements and located on plasmids. Furthermore, Gfp-plasmid transformation within a natural microbial community was enhanced by anthropogenic pollution levels. Our findings underscore anthropogenic pollution's pivotal role in shaping microbial communities and their antimicrobial resistome. Additionally, it may facilitate ARG dissemination through extracellular DNA plasmid uptake.
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Affiliation(s)
- Periyasamy Sivalingam
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy
| | - Raffaella Sabatino
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy; National Biodiversity Future Center (NBFC), Piazza Marina 61, 90133 Palermo, Italy
| | - Tomasa Sbaffi
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy; National Biodiversity Future Center (NBFC), Piazza Marina 61, 90133 Palermo, Italy
| | - Gianluca Corno
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy; National Biodiversity Future Center (NBFC), Piazza Marina 61, 90133 Palermo, Italy
| | - Diego Fontaneto
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy; National Biodiversity Future Center (NBFC), Piazza Marina 61, 90133 Palermo, Italy
| | - Giulia Borgomaneiro
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy
| | - Michela Rogora
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy
| | - Elena Crotti
- Department of Food Environmental and Nutritional Sciences, University of Milan, via Celoria 2, 20133 Milan, Italy
| | - Francesca Mapelli
- Department of Food Environmental and Nutritional Sciences, University of Milan, via Celoria 2, 20133 Milan, Italy
| | - Sara Borin
- Department of Food Environmental and Nutritional Sciences, University of Milan, via Celoria 2, 20133 Milan, Italy
| | - Andrea Lopez Pilar
- Biological Science Faculty, Complutense University of Madrid, Jose Antonio Novais 12, 28040 Madrid, Spain
| | - Ester M Eckert
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy; National Biodiversity Future Center (NBFC), Piazza Marina 61, 90133 Palermo, Italy
| | - Andrea Di Cesare
- National Research Council of Italy (CNR) - Water Research Institute (IRSA), Largo Tonolli 50, 28922 Verbania, Italy; National Biodiversity Future Center (NBFC), Piazza Marina 61, 90133 Palermo, Italy.
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Karasiński M, Wnorowska U, Daniluk T, Deptuła P, Łuckiewicz M, Paprocka P, Durnaś B, Skłodowski K, Sawczuk B, Savage PB, Piktel E, Bucki R. Investigating the Effectiveness of Ceragenins against Acinetobacter baumannii to Develop New Antimicrobial and Anti-Adhesive Strategies. Int J Mol Sci 2024; 25:7036. [PMID: 39000144 PMCID: PMC11241064 DOI: 10.3390/ijms25137036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024] Open
Abstract
A growing body of experimental data indicates that ceragenins (CSAs), which mimic the physicochemical properties of the host's cationic antimicrobial peptide, hold promise for the development of a new group of broad-spectrum antimicrobials. Here, using a set of in vivo experiments, we assessed the potential of ceragenins in the eradication of an important etiological agent of nosocomial infections, Acinetobacter baumannii. Assessment of the bactericidal effect of ceragenins CSA-13, CSA-44, and CSA-131 on clinical isolates of A. baumannii (n = 65) and their effectiveness against bacterial cells embedded in the biofilm matrix after biofilm growth on abiotic surfaces showed a strong bactericidal effect of the tested molecules regardless of bacterial growth pattern. AFM assessment of bacterial cell topography, bacterial cell stiffness, and adhesion showed significant membrane breakdown and rheological changes, indicating the ability of ceragenins to target surface structures of A. baumannii cells. In the cell culture of A549 lung epithelial cells, ceragenin CSA-13 had the ability to inhibit bacterial adhesion to host cells, suggesting that it interferes with the mechanism of bacterial cell invasion. These findings highlight the potential of ceragenins as therapeutic agents in the development of antimicrobial strategies against bacterial infections caused by A. baumannii.
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Affiliation(s)
- Maciej Karasiński
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, 15-222 Białystok, Poland; (M.K.); (U.W.); (T.D.); (K.S.)
| | - Urszula Wnorowska
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, 15-222 Białystok, Poland; (M.K.); (U.W.); (T.D.); (K.S.)
| | - Tamara Daniluk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, 15-222 Białystok, Poland; (M.K.); (U.W.); (T.D.); (K.S.)
| | - Piotr Deptuła
- Independent Laboratory of Nanomedicine, Medical University of Białystok, 15-222 Białystok, Poland; (P.D.); (M.Ł.); (E.P.)
| | - Milena Łuckiewicz
- Independent Laboratory of Nanomedicine, Medical University of Białystok, 15-222 Białystok, Poland; (P.D.); (M.Ł.); (E.P.)
| | - Paulina Paprocka
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University in Kielce, 25-317 Kielce, Poland; (P.P.); (B.D.)
| | - Bonita Durnaś
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University in Kielce, 25-317 Kielce, Poland; (P.P.); (B.D.)
| | - Karol Skłodowski
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, 15-222 Białystok, Poland; (M.K.); (U.W.); (T.D.); (K.S.)
| | - Beata Sawczuk
- Department of Prosthodontics, Medical University of Bialystok, Sklodowskiej 24a, 15-276 Bialystok, Poland;
| | - Paul B. Savage
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA;
| | - Ewelina Piktel
- Independent Laboratory of Nanomedicine, Medical University of Białystok, 15-222 Białystok, Poland; (P.D.); (M.Ł.); (E.P.)
| | - Robert Bucki
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, 15-222 Białystok, Poland; (M.K.); (U.W.); (T.D.); (K.S.)
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Narancic J, Gavric D, Kostanjsek R, Knezevic P. First Characterization of Acinetobacter baumannii-Specific Filamentous Phages. Viruses 2024; 16:857. [PMID: 38932150 PMCID: PMC11209303 DOI: 10.3390/v16060857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/17/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024] Open
Abstract
Filamentous bacteriophages belonging to the order Tubulavirales, family Inoviridae, significantly affect the properties of Gram-negative bacteria, but filamentous phages of many important pathogens have not been described so far. The aim of this study was to examine A. baumannii filamentous phages for the first time and to determine their effect on bacterial virulence. The filamentous phages were detected in 15.3% of A. baumannii strains as individual prophages in the genome or as tandem repeats, and a slightly higher percentage was detected in the culture collection (23.8%). The phylogenetic analyses revealed 12 new genera within the Inoviridae family. Bacteriophages that were selected and isolated showed structural and genomic characteristics of the family and were unable to form plaques. Upon host infection, these phages did not significantly affect bacterial twitching motility and capsule production but significantly affected growth kinetics, reduced biofilm formation, and increased antibiotic sensitivity. One of the possible mechanisms of reduced resistance to antibiotics is the observed decreased expression of efflux pumps after infection with filamentous phages.
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Affiliation(s)
- Jelena Narancic
- PK Lab., Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia; (J.N.); (D.G.)
| | - Damir Gavric
- PK Lab., Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia; (J.N.); (D.G.)
| | - Rok Kostanjsek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jaminkarjeva 101, SI-1000 Ljubljana, Slovenia;
| | - Petar Knezevic
- PK Lab., Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia; (J.N.); (D.G.)
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Ji C, Guo W, Amir H. Experience of diagnosis and treatment of hard-to-heal wounds infected with Acinetobacter baumannii: a case study. J Wound Care 2024; 33:278-285. [PMID: 38573906 DOI: 10.12968/jowc.2024.33.4.278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
OBJECTIVE To explore the efficacy of 0.01% hypochlorous acid (HOCl) in the treatment of hard-to-heal wounds infected by multidrug-resistant Acinetobacter baumannii. METHOD We report a case of hard-to-heal wounds on a patient's forearms that were infected by Acinetobacter baumannii. The wounds were treated with 0.01% HOCl. We reviewed the relevant literature and discussed the definition, epidemiology and pathogenesis of hard-to-heal wounds infected by Acinetobacter baumannii. We also explored the safety and efficacy of 0.01% HOCl for the treatment of hard-to-heal wounds infected with Acinetobacter baumannii. RESULTS After 3-4 weeks of treatment with 0.01% HOCl, the pain and pruritus of the wounds was gradually alleviated, the infection was controlled and the granulation tissue was fresh. The ulcers also shrank and the nutritional condition of the patient improved. In the fifth week, the skin of the patient's right thigh was grafted to repair the wounds, which then healed within 18 days. During the three years of follow-up, the patient had no relapse. CONCLUSION In our case, the 0.01% HOCl seemed to effectively inactivate the bacterial biological biofilm. This helped to promote wound healing, and was non-toxic to the tissues. We consider low-concentration HOCl to be safe and effective for the treatment of hard-to-heal wounds infected with Acinetobacter baumannii.
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Affiliation(s)
- Chaochao Ji
- The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang Province, China
| | - Wenyong Guo
- Institute of Basic Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Hammad Amir
- The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang Province, China
- Zhejiang Chinese Medical University, Hangzhou, Zhejiang Province, China
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Shen L, Zhang Z, Wang R, Wu S, Wang Y, Fu S. Metatranscriptomic data mining together with microfluidic card uncovered the potential pathogens and seasonal RNA viral ecology in a drinking water source. J Appl Microbiol 2024; 135:lxad310. [PMID: 38130237 DOI: 10.1093/jambio/lxad310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/26/2023] [Accepted: 12/20/2023] [Indexed: 12/23/2023]
Abstract
AIMS Despite metatranscriptomics becoming an emerging tool for pathogen surveillance, very little is known about the feasibility of this approach for understanding the fate of human-derived pathogens in drinking water sources. METHODS AND RESULTS We conducted multiplexed microfluidic cards and metatranscriptomic sequencing of the drinking water source in a border city of North Korea in four seasons. Microfluidic card detected norovirus, hepatitis B virus (HBV), enterovirus, and Vibrio cholerae in the water. Phylogenetic analyses showed that environmental-derived sequences from norovirus GII.17, genotype C of HBV, and coxsackievirus A6 (CA6) were genetically related to the local clinical isolates. Meanwhile, metatranscriptomic assembly suggested that several bacterial pathogens, including Acinetobacter johnsonii and V. cholerae might be prevalent in the studied region. Metatranscriptomic analysis recovered 349 species-level groups with substantial viral diversity without detection of norovirus, HBV, and CA6. Seasonally distinct virus communities were also found. Specifically, 126, 73, 126, and 457 types of viruses were identified in spring, summer, autumn, and winter, respectively. The viromes were dominated by the Pisuviricota phylum, including members from Marnaviridae, Dicistroviridae, Luteoviridae, Potyviridae, Picornaviridae, Astroviridae, and Picobirnaviridae families. Further phylogenetic analyses of RNA (Ribonucleic Acid)-dependent RNA polymerase (RdRp) sequences showed a diverse set of picorna-like viruses associated with shellfish, of which several novel picorna-like viruses were also identified. Additionally, potential animal pathogens, including infectious bronchitis virus, Bat dicibavirus, Bat nodavirus, Bat picornavirus 2, infectious bursal disease virus, and Macrobrachium rosenbergii nodavirus were also identified. CONCLUSIONS Our data illustrate the divergence between microfluidic cards and metatranscriptomics, highlighting that the combination of both methods facilitates the source tracking of human viruses in challenging settings without sufficient clinical surveillance.
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Affiliation(s)
- Lixin Shen
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Department of Microbiology, College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Ziqiang Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Department of Microbiology, College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Rui Wang
- College of Marine Science and Environment, Dalian Ocean University, Dalian 116023, China
| | - Shuang Wu
- College of Food Technology and Sciences, Shanghai Ocean University, Shanghai 200093, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Yongjie Wang
- College of Food Technology and Sciences, Shanghai Ocean University, Shanghai 200093, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai 200093, China
| | - Songzhe Fu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Department of Microbiology, College of Life Sciences, Northwest University, Xi'an 710069, China
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Ahmad I, Nadeem A, Mushtaq F, Zlatkov N, Shahzad M, Zavialov AV, Wai SN, Uhlin BE. Csu pili dependent biofilm formation and virulence of Acinetobacter baumannii. NPJ Biofilms Microbiomes 2023; 9:101. [PMID: 38097635 PMCID: PMC10721868 DOI: 10.1038/s41522-023-00465-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 11/23/2023] [Indexed: 12/17/2023] Open
Abstract
Acinetobacter baumannii has emerged as one of the most common extensive drug-resistant nosocomial bacterial pathogens. Not only can the bacteria survive in hospital settings for long periods, but they are also able to resist adverse conditions. However, underlying regulatory mechanisms that allow A. baumannii to cope with these conditions and mediate its virulence are poorly understood. Here, we show that bi-stable expression of the Csu pili, along with the production of poly-N-acetyl glucosamine, regulates the formation of Mountain-like biofilm-patches on glass surfaces to protect bacteria from the bactericidal effect of colistin. Csu pilus assembly is found to be an essential component of mature biofilms formed on glass surfaces and of pellicles. By using several microscopic techniques, we show that clinical isolates of A. baumannii carrying abundant Csu pili mediate adherence to epithelial cells. In addition, Csu pili suppressed surface-associated motility but enhanced colonization of bacteria into the lungs, spleen, and liver in a mouse model of systemic infection. The screening of c-di-GMP metabolizing protein mutants of A. baumannii 17978 for the capability to adhere to epithelial cells led us to identify GGDEF/EAL protein AIS_2337, here denoted PdeB, as a major regulator of Csu pili-mediated virulence and biofilm formation. Moreover, PdeB was found to be involved in the type IV pili-regulated robustness of surface-associated motility. Our findings suggest that the Csu pilus is not only a functional component of mature A. baumannii biofilms but also a major virulence factor promoting the initiation of disease progression by mediating bacterial adherence to epithelial cells.
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Affiliation(s)
- Irfan Ahmad
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, 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, SE-90187, Umeå, Sweden
| | - Fizza Mushtaq
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
- Institute of Biomedical and Allied Health Sciences, University of Health Sciences, Lahore, Pakistan
| | - Nikola Zlatkov
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
| | - Muhammad Shahzad
- Department of Pharmacology, University of Health Sciences, Lahore, Pakistan
| | - Anton V Zavialov
- Department of Biochemistry, University of Turku, Tykistökatu 6A, 20520, Turku, Finland
| | - Sun Nyunt Wai
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Bernt Eric Uhlin
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187, Umeå, Sweden
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Meng WS, Sui X, Xiao Y, Zou Q, Cui Y, Wang T, Chen Z, Li D. Regulating effects of chlorinated drinking water on cecal microbiota of broiler chicks. Poult Sci 2023; 102:103140. [PMID: 37844529 PMCID: PMC10585633 DOI: 10.1016/j.psj.2023.103140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 09/18/2023] [Accepted: 09/18/2023] [Indexed: 10/18/2023] Open
Abstract
In this study, 2 types of drinking water were provided to broiler chicks to evaluate the relationship between the bacterial load of drinking water and cecal microbiota. One type of drinking water was untreated, while the other type was daily treated with sodium dichlorocyanurate (50 mg/L). A total of 240 broiler chicks were divided into 2 groups based on their initial body weight. There were 6 replicates in each group, and each replicate cage contained 20 birds. Each cage was assigned to a different floor of the battery cage. On the final day, water samples were collected from each replicate cage at the opening of the drinking cup height, and one bird was selected from each replicate cage to obtain cecal content samples for measuring microbiota composition using the 16S rRNA technique. We found that drinking water treated with sodium dichlorocyanurate significantly reduced the richness and diversity of microbiota and diminished/disappeared most gram-negative bacteria. Broiler chicks that consumed chlorinated drinking water exhibited changes in the composition of cecal microbiota, with Alistipes serving as the marker species in the cecal content of broiler chicks that consumed untreated water, whereas AF12 served as the marker species in the cecal content of broiler chicks that consumed chlorinated drinking water. Functional prediction using the MetaCyc database and species composition analysis of metabolic pathways showed that changes in 7 metabolic pathways were related to the abundance of Providencia. Therefore, we concluded that chlorinated drinking water reduced the bacterial load in drinking water, thereby altering the cecal microbiota composition and regulating the metabolic activity of broiler chicks.
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Affiliation(s)
- Wei Shuang Meng
- College of Animal Science and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, China
| | - Xinxin Sui
- College of Animal Science and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, China
| | - Yingying Xiao
- Liaoning Kaiwei Biotechnology Co., Ltd., Jinzhou 121000, China
| | - Qiangqiang Zou
- College of Animal Science and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, China
| | - Yan Cui
- College of Animal Science and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, China
| | - Tieliang Wang
- College of Animal Science and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, China; Collaborative Innovation Center for Prevention and Control of Zoonoses, Jinzhou Medical University, Jinzhou 121001, China
| | - Zeliang Chen
- College of Animal Science and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, China; Collaborative Innovation Center for Prevention and Control of Zoonoses, Jinzhou Medical University, Jinzhou 121001, China
| | - Desheng Li
- College of Animal Science and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, China; Collaborative Innovation Center for Prevention and Control of Zoonoses, Jinzhou Medical University, Jinzhou 121001, China.
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Kayani H, Rasheed MA, Alonazi WB, Jamil F, Hussain A, Yan C, Ahmed R, Ibrahim M. Identification and genome-wide analysis provide insights into the genetic diversity and biotechnological potentials of novel cold-adapted Acinetobacter strain. Extremophiles 2023; 27:14. [PMID: 37354217 DOI: 10.1007/s00792-023-01301-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/12/2023] [Indexed: 06/26/2023]
Abstract
Extreme cold environments, such as polar regions or high-altitude mountains, are known for their challenging conditions including low temperatures, high salinity, and limited nutrient availability. Microbes that thrive in these environments have evolved specialized strategies to survive and function under such harsh conditions. The study aims to identify, sequence the genome, perform genome assembly, and conduct a comparative genome-wide analysis of Acinetobacter sp. strain P1, which was isolated from the Batura glacier regions of Pakistan. A basic local alignment search tool of NCBI using 16 s RNA gene sequence confirmed the strain Acinetobacter following phylogenetic analysis revealed that strain P1 clustered with Acinetobacter sp. strain AcBz01. The high-throughput Genome sequencing was done by the NovaSeq 6000 sequencing system following de novo genome assembly reported 23 contigs, a genome size of 3,732,502 bp containing approximately 3489 genes and 63 RNAs (60 tRNA, 3 rRNA). The comparative genome analysis revealed that Acinetobacter sp. strain P1 exhibited the highest homology with the Acinetobacter baumannii ATCC 17978 genome and encompassed 1668 indispensable genes, 1280 conserved genes 1821 specific genes suggesting high genomic plasticity and evolutionary diversity. The genes with functional assignments include exopolysaccharide phosphotransferase enzyme, cold-shock proteins, T6SS, membrane modifications, antibiotic resistance, and set of genes related to a wide range of metabolic characteristics such as exopolysaccharides were also present. Moreover, the structural prediction analysis of EPS proteins reveals that structural flexibility allows for conformational modifications during catalysis, which boosts or increases the catalytic effectiveness at lower temperatures. Overall, the identification of Acinetobacter, a cold-adapted bacterium, offers promising applications in bioremediation, enzyme production, food preservation, pharmaceutical development, and astrobiology. Further research and exploration of these microorganisms can unlock their full biotechnological potential and contribute to various industries and scientific endeavors.
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Affiliation(s)
- Hajra Kayani
- Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan
| | - Muhammad Asif Rasheed
- Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan
| | - Wadi B Alonazi
- Health Administration Department, College of Business Administration, King Saud University, Riyadh, Saudi Arabia
| | - Farrukh Jamil
- Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan
| | - Annam Hussain
- Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan
| | - ChangHui Yan
- Department of Computer Science, North Dakota State University Fargo United State of America, Fargo, USA
| | - Raza Ahmed
- Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan
- Health Administration Department, College of Business Administration, King Saud University, Riyadh, Saudi Arabia
- Department of Computer Science, North Dakota State University Fargo United State of America, Fargo, USA
- Department of Biotechnology, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, Pakistan
| | - Muhammad Ibrahim
- Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan.
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Marrujo SA, Hubble VB, Yang J, Wang M, Nemeth AM, Barlock SL, Juarez D, Smith RD, Melander RJ, Ernst RK, Chang M, Melander C. Dimeric 2-aminoimidazoles are highly active adjuvants for gram-positive selective antibiotics against Acinetobacter baumannii. Eur J Med Chem 2023; 253:115329. [PMID: 37023677 PMCID: PMC10158791 DOI: 10.1016/j.ejmech.2023.115329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
The Centers for Disease Control and Prevention (CDC) reports that hospital acquired infections have increased by 65% since 2019. One of the main contributors is the gram-negative bacterium Acinetobacter baumannii. Previously, we reported aryl 2-aminoimidazole (2-AI) adjuvants that potentiate macrolide antibiotics against A. baumannii. Macrolide antibiotics are typically used to treat infections caused by gram-positive bacteria, but are ineffective against most gram-negative bacteria. We describe a new class of dimeric 2-AIs that are highly active macrolide adjuvants, with lead compounds lowering minimum inhibitory concentrations (MICs) to or below the gram-positive breakpoint level against A. baumannii. The parent dimer lowers the clarithromycin (CLR) MIC against A. baumannii 5075 from 32 μg/mL to 1 μg/mL at 7.5 μM (3.4 μg/mL), and a subsequent structure activity relationship (SAR) study identified several compounds with increased activity. The lead compound lowers the CLR MIC to 2 μg/mL at 1.5 μM (0.72 μg/mL), far exceeding the activity of both the parent dimer and the previous lead aryl 2-AI. Furthermore, these dimeric 2-AIs exhibit considerably reduced mammalian cell toxicity compared to aryl-2AI adjuvants, with IC50s of the two lead compounds against HepG2 cells of >200 μg/mL, giving therapeutic indices of >250.
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Affiliation(s)
- Santiana A Marrujo
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Veronica B Hubble
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Jingdong Yang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Man Wang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Ansley M Nemeth
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Samantha L Barlock
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Dane Juarez
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Richard D Smith
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, USA
| | - Roberta J Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, USA
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Christian Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA.
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11
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Gan C, Langa E, Valenzuela A, Ballestero D, Pino-Otín MR. Synergistic Activity of Thymol with Commercial Antibiotics against Critical and High WHO Priority Pathogenic Bacteria. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12091868. [PMID: 37176927 PMCID: PMC10180827 DOI: 10.3390/plants12091868] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/15/2023]
Abstract
The use of synergistic combinations between natural compounds and commercial antibiotics may be a good strategy to fight against microbial resistance, with fewer side effects on human, animal and environmental, health. The antimicrobial capacity of four compounds of plant origin (thymol and gallic, salicylic and gentisic acids) was analysed against 14 pathogenic bacteria. Thymol showed the best antimicrobial activity, with MICs ranging from 125 µg/mL (for Acinetobacter baumannii, Pasteurella aerogenes, and Salmonella typhimurium) to 250 µg/mL (for Bacillus subtilis, Klebsiella aerogenes, Klebsiella pneumoniae, Serratia marcescens, Staphylococcus aureus, and Streptococcus agalactiae). Combinations of thymol with eight widely used antibiotics were studied to identify combinations with synergistic effects. Thymol showed synergistic activity with chloramphenicol against A. baumannii (critical priority by the WHO), with streptomycin and gentamicin against Staphylococcus aureus (high priority by the WHO), and with streptomycin against Streptococcus agalactiae, decreasing the MICs of these antibiotics by 75% to 87.5%. The kinetics of these synergies indicated that thymol alone at the synergy concentration had almost no effect on the maximum achievable population density and very little effect on the growth rate. However, in combination with antibiotics at the same concentration, it completely inhibited growth, confirming its role in facilitating the action of the antibiotic. The time-kill curves indicated that all the combinations with synergistic effects were mainly bactericidal.
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Affiliation(s)
- Cristina Gan
- Faculty of Health Sciences, Universidad San Jorge, 50830 Villanueva de Gállego, Zaragoza, Spain
| | - Elisa Langa
- Faculty of Health Sciences, Universidad San Jorge, 50830 Villanueva de Gállego, Zaragoza, Spain
| | - Antonio Valenzuela
- Faculty of Health Sciences, Universidad San Jorge, 50830 Villanueva de Gállego, Zaragoza, Spain
| | - Diego Ballestero
- Faculty of Health Sciences, Universidad San Jorge, 50830 Villanueva de Gállego, Zaragoza, Spain
| | - M Rosa Pino-Otín
- Faculty of Health Sciences, Universidad San Jorge, 50830 Villanueva de Gállego, Zaragoza, Spain
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12
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Valcek A, Philippe C, Whiteway C, Robino E, Nesporova K, Bové M, Coenye T, De Pooter T, De Coster W, Strazisar M, Van der Henst C. Phenotypic Characterization and Heterogeneity among Modern Clinical Isolates of Acinetobacter baumannii. Microbiol Spectr 2023; 11:e0306122. [PMID: 36475894 PMCID: PMC9927488 DOI: 10.1128/spectrum.03061-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022] Open
Abstract
Acinetobacter baumannii is an opportunistic pathogenic bacterium prioritized by WHO and CDC because of its increasing antibiotic resistance. Heterogeneity among strains represents the hallmark of A. baumannii bacteria. We wondered to what extent extensively used strains, so-called reference strains, reflect the dynamic nature and intrinsic heterogeneity of these bacteria. We analyzed multiple phenotypic traits of 43 nonredundant, modern, and multidrug-resistant, extensively drug-resistant, and pandrug-resistant clinical isolates and broadly used strains of A. baumannii. Comparison of these isolates at the genetic and phenotypic levels confirmed a high degree of heterogeneity. Importantly, we observed that a significant portion of modern clinical isolates strongly differs from several historically established strains in the light of colony morphology, cellular density, capsule production, natural transformability, and in vivo virulence. The significant differences between modern clinical isolates of A. baumannii and established strains could hamper the study of A. baumannii, especially concerning its virulence and resistance mechanisms. Hence, we propose a variable collection of modern clinical isolates that are characterized at the genetic and phenotypic levels, covering a wide range of the phenotypic spectrum, with six different macrocolony type groups, from avirulent to hypervirulent phenotypes, and with naturally noncapsulated to hypermucoid strains, with intermediate phenotypes as well. Strain-specific mechanistic observations remain interesting per se, and established "reference" strains have undoubtedly been shown to be very useful to study basic mechanisms of A. baumannii biology. However, any study based on a specific strain of A. baumannii should be compared to modern and clinically relevant isolates. IMPORTANCE Acinetobacter baumannii is a bacterium prioritized by the CDC and WHO because of its increasing antibiotic resistance, leading to treatment failures. The hallmark of this pathogen is the high heterogeneity observed among isolates, due to a very dynamic genome. In this context, we tested if a subset of broadly used isolates, considered "reference" strains, was reflecting the genetic and phenotypic diversity found among currently circulating clinical isolates. We observed that the so-called reference strains do not cover the whole diversity of the modern clinical isolates. While formerly established strains successfully generated a strong base of knowledge in the A. baumannii field and beyond, our study shows that a rational choice of strain, related to a specific biological question, should be taken into consideration. Any data obtained with historically established strains should also be compared to modern and clinically relevant isolates, especially concerning drug screening, resistance, and virulence contexts.
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Affiliation(s)
- Adam Valcek
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Chantal Philippe
- Research Unit in the Biology of Microorganisms (URBM), NARILIS, University of Namur (UNamur), Namur, Belgium
| | - Clémence Whiteway
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Etienne Robino
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Kristina Nesporova
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Mona Bové
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tim De Pooter
- Neuromics Support Facility, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Wouter De Coster
- Applied and Translational Neurogenomics Group, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium
- Applied and Translational Neurogenomics Group, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Mojca Strazisar
- Neuromics Support Facility, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Charles Van der Henst
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
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Semenec L, Cain AK, Dawson CJ, Liu Q, Dinh H, Lott H, Penesyan A, Maharjan R, Short FL, Hassan KA, Paulsen IT. Cross-protection and cross-feeding between Klebsiella pneumoniae and Acinetobacter baumannii promotes their co-existence. Nat Commun 2023; 14:702. [PMID: 36759602 PMCID: PMC9911699 DOI: 10.1038/s41467-023-36252-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 01/20/2023] [Indexed: 02/11/2023] Open
Abstract
Acinetobacter baumannii and Klebsiella pneumoniae are opportunistic pathogens frequently co-isolated from polymicrobial infections. The infections where these pathogens co-exist can be more severe and recalcitrant to therapy than infections caused by either species alone, however there is a lack of knowledge on their potential synergistic interactions. In this study we characterise the genomes of A. baumannii and K. pneumoniae strains co-isolated from a single human lung infection. We examine various aspects of their interactions through transcriptomic, phenomic and phenotypic assays that form a basis for understanding their effects on antimicrobial resistance and virulence during co-infection. Using co-culturing and analyses of secreted metabolites, we discover the ability of K. pneumoniae to cross-feed A. baumannii by-products of sugar fermentation. Minimum inhibitory concentration testing of mono- and co-cultures reveals the ability for A. baumannii to cross-protect K. pneumoniae against the cephalosporin, cefotaxime. Our study demonstrates distinct syntrophic interactions occur between A. baumannii and K. pneumoniae, helping to elucidate the basis for their co-existence in polymicrobial infections.
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Affiliation(s)
- Lucie Semenec
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Amy K Cain
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Catherine J Dawson
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Qi Liu
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Hue Dinh
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Hannah Lott
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Anahit Penesyan
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Ram Maharjan
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Francesca L Short
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Karl A Hassan
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia.
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia.
| | - Ian T Paulsen
- ARC Centre of Excellence in Synthetic Biology, School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia.
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2113, Australia.
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14
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Hu MY, Yu QZ, Lin JQ, Fang SG. Sexual Dimorphism of the Gut Microbiota in the Chinese Alligator and Its Convergence in the Wild Environment. Int J Mol Sci 2022; 23:12140. [PMID: 36292992 PMCID: PMC9603114 DOI: 10.3390/ijms232012140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/05/2022] [Accepted: 10/09/2022] [Indexed: 11/27/2022] Open
Abstract
The gut microbiota forms a complex microecosystem in vertebrates and is affected by various factors. As a key intrinsic factor, sex has a persistent impact on the formation and development of gut microbiota. Few studies have analyzed sexual dimorphism of gut microbiota, particularly in wild animals. We used 16S rRNA gene sequencing to analyze the gut microbiota of juvenile and adult Chinese alligators, and untargeted metabolomics to study serum metabolomes of adult alligators. We observed significant sexual differences in the community diversity in juvenile, but not adult, alligators. In terms of taxonomic composition, the phylum Fusobacteriota and genus Cetobacterium were highly abundant in adult alligators, similar to those present in carnivorous fishes, whereas the gut microbiota composition in juvenile alligators resembled that in terrestrial reptiles, indicating that adults are affected by their wild aquatic environment and lack sex dimorphism in gut microbiota. The correlation analysis revealed that the gut microbiota of adults was also affected by cyanobacteria in the external environment, and this effect was sex-biased and mediated by sex hormones. Overall, this study reveals sexual differences in the gut microbiota of crocodilians and their convergence in the external environment, while also providing insights into host-microbiota interactions in wildlife.
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Affiliation(s)
- Meng-Yuan Hu
- MOE Key Laboratory of Biosystems Homeostasis and Protection, State Conservation Center for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Qin-Zhang Yu
- MOE Key Laboratory of Biosystems Homeostasis and Protection, State Conservation Center for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jian-Qing Lin
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Science, Shantou University, Shantou 515063, China
| | - Sheng-Guo Fang
- MOE Key Laboratory of Biosystems Homeostasis and Protection, State Conservation Center for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
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15
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Basardeh E, Piri-Gavgani S, Soltanmohammadi B, Ghanei M, Omrani MD, Soezi M, Shokrgozar MA, Azizi M, Fateh A, Vaziri F, Siadat SD, Sharifzadeh Z, Rahimi-Jamnani F. Anti- Acinetobacter baumannii single-chain variable fragments show direct bactericidal activity. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2022; 25:1141-1149. [PMID: 36246061 PMCID: PMC9526879 DOI: 10.22038/ijbms.2022.64062.14106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 08/21/2022] [Indexed: 11/06/2022]
Abstract
Objectives The high resistance rate of Acinetobacter baumannii and the limited number of available antibiotics have prompted a worldwide effort to develop effective antimicrobial agents. Accordingly, identifying single-chain variable fragment antibodies (scFvs), capable of exerting direct antibacterial activity in an immune system-independent manner, may be making immunocompromised patients more susceptible to A. baumannii infections. Materials and Methods To isolate bactericidal scFvs targeting A. baumannii, we panned a large human scFv phage display library against whole-cell extensively drug-resistant (XDR) A. baumannii strains grown as biofilm or cultured with human blood or human peripheral blood mononuclear cells plus plasma. The binding of scFv-phages to A. baumannii was assessed by the dot-blot assay. Soluble scFvs, derived from the selected phages, were assessed based on their ability to bind and inhibit the growth of A. baumannii. Results Five phage clones showed the highest reactivity toward A. baumannii. Among five soluble scFvs, derived from positive phage clones, two scFvs, EB211 and EB279, had high expression yields and displayed strong binding to A. baumannii compared with the controls. Moreover, XDR A. baumannii strains treated with positively-charged scFvs, including EB211, EB279, or a cocktail of EB211 and EB279 (200 µg/ml), displayed lower viability (approximately 50%, 78%, and 40% viability, respectively) compared with PBS-treated bacteria. Conclusion These results suggest that combining last-resort antibiotics with bactericidal scFvs could provide promising outcomes in immunocompromised individuals with A. baumannii infections.
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Affiliation(s)
- Eilnaz Basardeh
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Somayeh Piri-Gavgani
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Behnoush Soltanmohammadi
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Mostafa Ghanei
- Chemical Injuries Research Center, Systems Biology and Poisoning Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Mir Davood Omrani
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahdieh Soezi
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | | | - Masoumeh Azizi
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Abolfazl Fateh
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Farzam Vaziri
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Seyed Davar Siadat
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | | | - Fatemeh Rahimi-Jamnani
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran, Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran ,Corresponding author: Fatemeh Rahimi-Jamnani. Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran. Tel: +98-21-66953311; Fax: +98-21-66465132;
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16
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Jovchevski R, Popovska K, Todosovska Ristovska A, Lameski M, Preshova A, Selmani M, Nedelkoska S, Veljanovski H, Gjoshevska M. Detection of biofilm production and antimicrobial susceptibility in clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa. Arch Public Health 2022. [DOI: 10.3889/aph.2022.6053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Acinetobacter baumannii and Pseudomonas aeruginosa are commensal which commonly colonize humans. As a result of their ubiquitous nature, reservoirs in hospital environment and resistance to many antimicrobial agents they are responsible for hospital – acquired infections. Additionally treatment of these infections is difficult because of the ability for biofilm formation. Aim of the paper was to determine the association between biofilm formation on medical devices and antibiotic resistance profile, compared to respiratory samples in clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa. Material and methods: The study comprised 50 clinical samples (36 from medical devices and 14 as а control group from respiratory secretions). Acinetobacter baumannii and Pseudomonas aeruginosa were identified by routine microbiological methods. Modification of the microtiter plate assay described by Stepanovic et al. was used to investigate the formation of biofilm. The antimicrobial susceptibility testing was performed according to EUCAST guidelines. Results: Of the 50 analyzed strains, 16 (32%) were non-biofilm producers, and 34 (68%) were producing biofilms. Out of these, 29 (58%) were from medical devices, and 5 (10%) from the control group. Acinetobacter baumannii showed biofilm formation in 19 (67.9%), of which 17 (60.7%) from medical devices, and 2 (7.1%) from control group. Pseudomonas aeruginosa produced biofilm in 15 (68.1%), of which 12 (54.5%) from medical devices, and 3 (13.6%) from the control group. Multidrug resistance was detected in 40 (80%). All strains of Acinetobacter baumannii were multidrug resistant (MDR). For Pseudomonas aeruginosa, 11 (73.3%) biofilm forming isolates were MDR, and 1 (14.2%) non-biofilm forming isolate was MDR. Conclusion: Biofilm production was higher in strains from medical devices. Eighty percent of isolates were MDR. This is a serious challenge for treatment of these hospital-acquired infections.
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Metagenomic Insights into Pathogenic Characterization of ST410 Acinetobacter nosocomialis Prevalent in China. Pathogens 2022; 11:pathogens11080838. [PMID: 36014959 PMCID: PMC9414201 DOI: 10.3390/pathogens11080838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 07/16/2022] [Accepted: 07/25/2022] [Indexed: 02/01/2023] Open
Abstract
Acinetobacter nosocomialis is a prevalent opportunistic pathogen that causes hospital-acquired infections. The increasing threats from A. nosocomialis infections have led to attention from the scientific and medical communities. Metagenomic next-generation sequencing (mNGS) was performed for an exudate specimen collected from an ICU patient with wound infection, followed by sepsis, in Tongji Hospital. Three assembly strategies were employed to recover the genome of A. nosocomialis in the metagenomic sample. Together with publicly available genomes of A. nosocomialis, the features of population genetics and molecular epidemiology were deeply analyzed. A draft genome was reconstructed for the metagenomic strain WHM01, derived from the ST410 A. nosocomialis dominating the microbial community, thereby prompting its highly pathogenic risk, which is associated with infection and persistence. The structure of the bacterial pangenome was characterized, including the 1862 core and 11,815 accessory genes present in the 157 strains. The genetic diversity of the genes coding for the 128 virulence factors assigned to 14 functional categories was uncovered in this nosocomial pathogen, such as the lipooligosaccharide, capsule, type IV pilus, and outer membrane proteins. Our work revealed genomic properties of ST410 A. nosocomialis, which is prevalent in China, and further highlighted that metagenomic surveillance may be a prospective application for evaluating the pathogenic characteristics of the nosocomial opportunistic pathogens.
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18
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Djahanschiri B, Di Venanzio G, Distel JS, Breisch J, Dieckmann MA, Goesmann A, Averhoff B, Göttig S, Wilharm G, Feldman MF, Ebersberger I. Evolutionarily stable gene clusters shed light on the common grounds of pathogenicity in the Acinetobacter calcoaceticus-baumannii complex. PLoS Genet 2022; 18:e1010020. [PMID: 35653398 PMCID: PMC9162365 DOI: 10.1371/journal.pgen.1010020] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/04/2022] [Indexed: 11/19/2022] Open
Abstract
Nosocomial pathogens of the Acinetobacter calcoaceticus-baumannii (ACB) complex are a cautionary example for the world-wide spread of multi- and pan-drug resistant bacteria. Aiding the urgent demand for novel therapeutic targets, comparative genomics studies between pathogens and their apathogenic relatives shed light on the genetic basis of human-pathogen interaction. Yet, existing studies are limited in taxonomic scope, sensing of the phylogenetic signal, and resolution by largely analyzing genes independent of their organization in functional gene clusters. Here, we explored more than 3,000 Acinetobacter genomes in a phylogenomic framework integrating orthology-based phylogenetic profiling and microsynteny conservation analyses. We delineate gene clusters in the type strain A. baumannii ATCC 19606 whose evolutionary conservation indicates a functional integration of the subsumed genes. These evolutionarily stable gene clusters (ESGCs) reveal metabolic pathways, transcriptional regulators residing next to their targets but also tie together sub-clusters with distinct functions to form higher-order functional modules. We shortlisted 150 ESGCs that either co-emerged with the pathogenic ACB clade or are preferentially found therein. They provide a high-resolution picture of genetic and functional changes that coincide with the manifestation of the pathogenic phenotype in the ACB clade. Key innovations are the remodeling of the regulatory-effector cascade connecting LuxR/LuxI quorum sensing via an intermediate messenger to biofilm formation, the extension of micronutrient scavenging systems, and the increase of metabolic flexibility by exploiting carbon sources that are provided by the human host. We could show experimentally that only members of the ACB clade use kynurenine as a sole carbon and energy source, a substance produced by humans to fine-tune the antimicrobial innate immune response. In summary, this study provides a rich and unbiased set of novel testable hypotheses on how pathogenic Acinetobacter interact with and ultimately infect their human host. It is a comprehensive resource for future research into novel therapeutic strategies. The spread of multi- and pan-drug resistant bacterial pathogens is a worldwide threat to human health. Understanding the genetics of host colonization and infection can substantially help in devising novel ways of treatment. Acinetobacter baumannii, a nosocomial pathogen ranked top by the World Health Organization in the list of bacteria for which novel therapeutic approaches are needed, is a prime example. Here, we have carved out the genetic make-up that distinguishes A. baumannii and its pathogenic next relatives from other and mostly apathogenic Acinetobacter species. We found a rich spectrum of pathways and regulatory modules that reveal how the pathogens have modified biofilm formation, iron scavenging, and their carbohydrate metabolism to adapt to their human host. Among these, the capability to metabolize kynurenine is particularly intriguing. Humans produce this substance to contain bacterial invaders and to fine-tune the innate immune response. But A. baumannii and closely related pathogens found a way to feed on kynurenine. This suggests that the pathogens might be able to dysregulate the human immune response. In summary, our study substantially deepens the understanding of how a highly critical pathogen interacts with its host, which substantially eases the identification of novel targets for innovative therapeutic strategies.
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Affiliation(s)
- Bardya Djahanschiri
- Applied Bioinformatics Group, Inst. of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Gisela Di Venanzio
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jesus S. Distel
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jennifer Breisch
- Inst. of Molecular Biosciences, Department of Molecular Microbiology and Bioenergetics, Goethe University Frankfurt, Frankfurt am Main, Germany
| | | | - Alexander Goesmann
- Bioinformatics and Systems Biology, Justus Liebig University Gießen, Gießen, Germany
| | - Beate Averhoff
- Inst. of Molecular Biosciences, Department of Molecular Microbiology and Bioenergetics, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Stephan Göttig
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
| | | | - Mario F. Feldman
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Ingo Ebersberger
- Applied Bioinformatics Group, Inst. of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
- Senckenberg Biodiversity and Climate Research Centre (S-BIKF), Frankfurt am Main, Germany
- LOEWE Center for Translational Biodiversity Genomics (TBG), Frankfurt am Main, Germany
- * E-mail:
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19
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Ding Z, Li Z, Zhao Y, Hao J, Li T, Liu Y, Zeng Z, Liu J. Phenotypic and Genotypic Characteristics of a Tigecycline-Resistant Acinetobacter pittii Isolate Carrying bla NDM-1 and the Novel bla OXA Allelic Variant bla OXA-1045. Front Microbiol 2022; 13:868152. [PMID: 35602052 PMCID: PMC9116503 DOI: 10.3389/fmicb.2022.868152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 03/30/2022] [Indexed: 11/13/2022] Open
Abstract
A tigecycline-resistant Acinetobacter pittii clinical strain from pleural fluid carrying a blaNDM–1 gene and a novel blaOXA gene, blaOXA–1045, was isolated and characterized. The AP2044 strain acquired two copies of the blaNDM–1 gene and six antibiotic resistance genes (ARGs) from other pathogens. According to the whole-genome investigation, the GC ratios of ARGs (50–60%) were greater than those of the chromosomal backbone (39.46%), indicating that ARGs were horizontally transferred. OXA-1045 belonged to the OXA-213 subfamily and the amino acid sequence of OXA-1045 showed 89% similarity to the amino acid sequences of OXA-213. Then, blaOXA–1045 and blaOXA–213 were cloned and the minimum inhibitory concentrations (MICs) of β-lactams in the transformants were determined using the broth microdilution method. OXA-1045 was able to confer a reduced susceptibility to piperacillin and piperacillin-tazobactam compared to OXA-213. AP2044 strain exhibited low pathogenicity in Galleria mellonella infection models. The observation of condensed biofilm using the crystal violet staining method and scanning electron microscopy (SEM) suggested that the AP2044 strain was a weak biofilm producer. Quantitative reverse transcription-PCR (qRT-PCR) was used to detect the expression of resistance-nodulation-cell division (RND) efflux pump-related genes. The transcription level of adeB and adeJ genes increased significantly and was correlated with tigecycline resistance. Therefore, our genomic and phenotypic investigations revealed that the AP2044 strain had significant genome plasticity and natural transformation potential, and the emergence of antibiotic resistance in these unusual bacteria should be a concern for future investigations.
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Affiliation(s)
- Zixuan Ding
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Zhaoyinqian Li
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Yuanqing Zhao
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jingchen Hao
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Tingting Li
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Yao Liu
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Zhangrui Zeng
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jinbo Liu
- Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
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20
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Bharathi SV, Venkataramaiah M, Rajamohan G. Genotypic and Phenotypic Characterization of Novel Sequence Types of Carbapenem-Resistant Acinetobacter baumannii, With Heterogeneous Resistance Determinants and Targeted Variations in Efflux Operons. Front Microbiol 2022; 12:738371. [PMID: 35002996 PMCID: PMC8735875 DOI: 10.3389/fmicb.2021.738371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/16/2021] [Indexed: 01/21/2023] Open
Abstract
Acinetobacter baumannii has emerged as one of the dominant nosocomial human pathogens associated with high morbidity and mortality globally. Increased incidences of carbapenem-resistant A. baumannii (CRAB) have resulted in an enormous socioeconomic burden on health-care systems. Here, we report the genotypic and phenotypic characterization of novel ST1816 and ST128 variants in A. baumannii strains belonging to International clone II (GC2) with capsule types KL1:OCL8 and KL3:OCL1d from India. Sequence analysis revealed the presence of diverse virulome and resistome in these clinical strains, in addition to islands, prophages, and resistance genes. The oxacillinase bla OXA-23 detected in the genomic island also highlighted the coexistence of bla OXA-66 /bla OXA-98 , bla ADC73 /bla ADC-3 , and bla TEM-1D in their mobile scaffolds, which is alarming. Together with these resistance-determining enzymes, multidrug efflux transporters also harbored substitutions, with increased expression in CRAB strains. The hotspot mutations in colistin resistance-conferring operons, PmrAB, LpxACD, and AdeRS, were additionally confirmed. Phenotype microarray analysis indicated that multidrug-resistant strains A. baumannii DR2 and A. baumannii AB067 preferred a range of antimicrobial compounds as their substrates relative to the other. To our knowledge, this is the first comprehensive report on the characterization of A. baumannii variants ST1816 and ST128, with different genetic makeup and genome organization. The occurrence of CRAB infections worldwide is a severe threat to available limited therapeutic options; hence, continued surveillance to monitor the emergence and dissemination of such novel ST variants in A. baumannii is imperative.
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Affiliation(s)
- Srinivasan Vijaya Bharathi
- Molecular Biology Division, Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
| | - Manjunath Venkataramaiah
- Molecular Biology Division, Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
| | - Govindan Rajamohan
- Molecular Biology Division, Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
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21
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Hansen BT, Maschkowitz G, Podschun R, Fickenscher H. The Kinocidin Interleukin-26 Shows Immediate Antimicrobial Effects Even to Multi-resistant Isolates. Front Microbiol 2021; 12:757215. [PMID: 34733265 PMCID: PMC8558509 DOI: 10.3389/fmicb.2021.757215] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/28/2021] [Indexed: 11/24/2022] Open
Abstract
The cationic proinflammatory cytokine Interleukin 26 (IL-26) shows antibacterial activity and inhibits the replication of cytomegalovirus and hepatitis C virus. This study evaluates the early microbicidal activities of IL-26 against major bacterial species including multi-resistant variants and Candida albicans. Recombinant IL-26 was bacterially expressed and studied for its microbicidal effects in culture. We show that IL-26 has strong 90% bactericidal activities against Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii. Similarly, IL-26 sensitivity was also detectable in vancomycin-resistant Enterococcus species, methicillin-resistant S. aureus, and carbapenem-resistant A. baumannii clinical isolates. Additionally, a significant, albeit weak fungicidal effect against Candida albicans was observed. Activities against Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa were not detectable. The proinflammatory cytokine and kinocidin IL-26 shows strong bactericidal activities against A. baumannii and, almost selectively, against Gram-positive bacteria.
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Affiliation(s)
- Bjoern-Thore Hansen
- Institute for Infection Medicine, Christian-Albrecht University of Kiel and University Hospital Schleswig-Holstein, Kiel, Germany
| | - Gregor Maschkowitz
- Institute for Infection Medicine, Christian-Albrecht University of Kiel and University Hospital Schleswig-Holstein, Kiel, Germany
| | - Rainer Podschun
- Institute for Infection Medicine, Christian-Albrecht University of Kiel and University Hospital Schleswig-Holstein, Kiel, Germany
| | - Helmut Fickenscher
- Institute for Infection Medicine, Christian-Albrecht University of Kiel and University Hospital Schleswig-Holstein, Kiel, Germany
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22
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Wang X, Loh B, Altamirano FG, Yu Y, Hua X, Leptihn S. Colistin- phage combinations decrease antibiotic resistance in A. baumannii via changes in envelope architecture. Emerg Microbes Infect 2021; 10:2205-2219. [PMID: 34736365 PMCID: PMC8648044 DOI: 10.1080/22221751.2021.2002671] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Multidrug-resistant bacterial infections are becoming increasingly common, with only few last-resort antibiotics such as colistin available for clinical therapy. An alternative therapeutic strategy gaining momentum is phage therapy, which has the advantage of not being affected by bacterial resistance to antibiotics. However, a major challenge in phage therapy is the rapid emergence of phage-resistant bacteria. In this work, our main aim was to understand the mechanisms of phage-resistance used by the top priority pathogen Acinetobacter baumannii. We isolated the novel phage Phab24, capable of infecting colistin-sensitive and -resistant strains of A. baumannii. After co-incubating Phab24 with its hosts, we obtained phage-resistant mutants which were characterized on both genotypic and phenotypic levels. Using whole genome sequencing, we identified phage-resistant strains that displayed mutations in genes that alter the architecture of the bacterial envelope at two levels: the capsule and the outer membrane. Using an adsorption assay, we confirmed that phage Phab24 uses the bacterial capsule as its primary receptor, with the outer membrane possibly serving as the secondary receptor. Interestingly, the phage-resistant isolates were less virulent compared to the parental strains in a Galleria mellonella infection model. Most importantly, we observed that phage-resistant bacteria that evolved in the absence of antibiotics exhibited an increased sensitivity to colistin, even though the antibiotic resistance mechanism per se remained unaltered. This increase in antibiotic sensitivity is a direct consequence of the phage-resistance mechanism, and could potentially be exploited in the clinical setting.
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Affiliation(s)
- Xiaoqing Wang
- Zhejiang University-University of Edinburgh (ZJU-UoE) Institute, Zhejiang University, Haining, China.,Medical school, Lishui University, Lishui, China
| | | | - Fernando Gordillo Altamirano
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia.,Centre to Impact AMR, Monash University, Clayton, Victoria, Australia
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China .,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Xiaoting Hua
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China .,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Sebastian Leptihn
- Zhejiang University-University of Edinburgh (ZJU-UoE) Institute, Zhejiang University, Haining, China.,Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China .,University of Edinburgh Medical School, Biomedical Sciences, College of Medicine & Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
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23
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Kim N, Son JH, Kim K, Kim HJ, Kim YJ, Shin M, Lee JC. Global regulator DksA modulates virulence of Acinetobacter baumannii. Virulence 2021; 12:2750-2763. [PMID: 34696704 PMCID: PMC8583241 DOI: 10.1080/21505594.2021.1995253] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
DksA with (p)ppGpp regulates a wide range of gene transcriptions during the stringent response. The aim of this study was to identify a DksA ortholog in Acinetobacter baumannii and clarify the roles of DksA in bacterial physiology and virulence. The ∆dksA mutant and its complemented strains were constructed using A. baumannii ATCC 17978. The AlS_0248 in A. baumannii ATCC 17978 was identified to dksA using sequence homology, protein structure prediction, and gene expression patterns under different culture conditions. The ∆dksA mutant strain showed a filamentous morphology compared with the wild-type (WT) strain. Bacterial growth was decreased in the ∆dksA mutant strain under static conditions. Surface motility was decreased in the ∆dksA mutant strain compared with the WT strain. In contrast, biofilm formation was increased and biofilm-associated genes, such as bfmR/S and csuC/D/E, were upregulated in the ∆dksA mutant strain. The ∆dksA mutant strain produced less autoinducers than the WT strain. The expression of abaI and abaR was significantly decreased in the ∆dksA mutant strain. Furthermore, the ∆dksA mutant strain showed less bacterial burden and milder histopathological changes in the lungs of mice than the WT strain. Mice survival was also significantly different between the ∆dksA mutant and WT strains. Conclusively, DksA is directly or indirectly involved in regulating a wide range of genes associated with bacterial physiology and virulence, which contributes to the pathogenesis of A. baumannii. Thus, DksA is a potential anti-virulence target for A. baumannii infection.
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Affiliation(s)
- Nayeong Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Joo Hee Son
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Kyeongmin Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Hyo Jeong Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Yoo Jeong Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Minsang Shin
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Je Chul Lee
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
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24
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Sanz-García F, Gil-Gil T, Laborda P, Ochoa-Sánchez LE, Martínez JL, Hernando-Amado S. Coming from the Wild: Multidrug Resistant Opportunistic Pathogens Presenting a Primary, Not Human-Linked, Environmental Habitat. Int J Mol Sci 2021; 22:8080. [PMID: 34360847 PMCID: PMC8347278 DOI: 10.3390/ijms22158080] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/22/2021] [Accepted: 07/24/2021] [Indexed: 12/24/2022] Open
Abstract
The use and misuse of antibiotics have made antibiotic-resistant bacteria widespread nowadays, constituting one of the most relevant challenges for human health at present. Among these bacteria, opportunistic pathogens with an environmental, non-clinical, primary habitat stand as an increasing matter of concern at hospitals. These organisms usually present low susceptibility to antibiotics currently used for therapy. They are also proficient in acquiring increased resistance levels, a situation that limits the therapeutic options for treating the infections they cause. In this article, we analyse the most predominant opportunistic pathogens with an environmental origin, focusing on the mechanisms of antibiotic resistance they present. Further, we discuss the functions, beyond antibiotic resistance, that these determinants may have in the natural ecosystems that these bacteria usually colonize. Given the capacity of these organisms for colonizing different habitats, from clinical settings to natural environments, and for infecting different hosts, from plants to humans, deciphering their population structure, their mechanisms of resistance and the role that these mechanisms may play in natural ecosystems is of relevance for understanding the dissemination of antibiotic resistance under a One-Health point of view.
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Affiliation(s)
| | | | | | | | - José L. Martínez
- Centro Nacional de Biotecnología, CSIC, 28049 Madrid, Spain; (F.S.-G.); (T.G.-G.); (P.L.); (L.E.O.-S.); (S.H.-A.)
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25
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Hatefi Oskuei R, Darvish Alipour Astaneh S, Rasooli I. A conserved region of Acinetobacter trimeric autotransporter adhesion, Ata, provokes suppression of Acinetobacter baumannii virulence. Arch Microbiol 2021; 203:3483-3493. [PMID: 33907866 DOI: 10.1007/s00203-021-02343-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 04/17/2021] [Accepted: 04/21/2021] [Indexed: 01/02/2023]
Abstract
The Acinetobacter trimeric autotransporter adhesin (Ata) is an important virulence factor. The conserved region from the genomic sequence of a 6777bp/2258 amino acid of Acinetobacter baumannii ATCC®19606™ ata was explored. A 263aa of the C-terminal of Ata (rcAta263) was expressed. The effect of rcAta263 on A. baumannii virulence was studied in a murine model. IgG and IgA were elicited and the mice groups challenged with A. baumannii showed significant survival rates from 66 to 100%. The bacterial loads were determined in the spleens, livers, and lungs of both control and test groups. The adhesion rate of A. baumannii to A549 cells in the presence of serum, cytotoxicity, mutagenicity, and biofilm disruption potential of rcAta263 were determined. Intraperitoneally challenged groups showed a significantly reduced bacterial load in the organs of the immunized mice. Intranasal challenge reduced 4 logs of bacterial CFU/g in the test group. The immunized mice sera reduced adherence of A. baumannii to A549 cells to 80%. No cytotoxic or mutagenic effect was detected. Biofilm disruption was significantly increased in the presence of immunized mice sera. Immunization with the conserved region of Ata significantly combats the virulence of A. baumannii which could be considered as a therapeutic strategy to control A. baumannii infections.
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Affiliation(s)
- Ramin Hatefi Oskuei
- Department of Biology, Shahed University, Tehran-Qom Express way, Tehran, 3319118651, Iran
| | - Shakiba Darvish Alipour Astaneh
- Department of Biotechnology, Semnan University, Central Administration of Semnan University, Campus 1, Semnan, 35131-19111, I. R. of Iran
| | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran-Qom Express way, Tehran, 3319118651, Iran.
- Molecular Microbiology Research Center and Department of Biology, Shahed University, Tehran, Iran.
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26
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El Khatib LS, Yacoub MA, Bdour SM, Shehabi AA. Phagoburst Response Level of Neutrophils to Septic and Non-Septic Acinetobacter baumannii Isolates. Open Microbiol J 2021. [DOI: 10.2174/1874285802115010016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background:
Acinetobacter baumannii is an opportunistic pathogen causing community-acquired and nosocomial infections. Dissemination of infection to blood causes septicemia associated with serious morbidity and mortality of patients. Neutrophils are essential for the control of A. baumannii infections by different mechanisms, including oxidative burst.
Aims:
This study was conducted as an attempt to determine the effect of septicemic and non-septicemic A. baumannii isolates on the phagoburst response of neutrophils.
Methods:
Neutrophils were isolated from an immunocompetent individual; chronic myeloid leukemia (CML) and lung solid tumor (ST) patients. The phagoburst response of these neutrophils to various strains of A. baumannii isolated from septic and non-septic patients was investigated by flow cytometer.
Results:
The presence of this pathogen lowered the phagoburst response in the different types of neutrophils compared to their response to the opsonized Escherichia coli. The phagoburst response of the neutrophils from the immunocompetent individual was significantly higher than that of neutrophils from the immunodeficient patients when stimulated by the septicemic or nonsepticemic A. baumannii isolates. The isolate type (septicemic or non-septicemic) had no significant effect on the neutrophil phagoburst response of the immunocompetent individual and a significant effect on the phagoburst response of neutrophils from the immunodeficient patients. The phagoburst response of the neutrophils from the immunodeficient patients stimulated by septicemic A. baumannii isolates was significantly lower than that when neutrophils stimulated by the nonsepticemic isolates. Also, there was a significant difference in the phagoburst response of neutrophils from the CML and ST patients when stimulated by the septicemic and non-septicemic isolates. This observation might be due to the combined effect of virulent A. baumannii isolates and the chemotherapy regime the patient was undertaking.
Conclusion:
The results suggest that both the isolate type and the source of neutrophils have a significant effect on the neutrophil phagoburst response. The potential virulence of the septicemic A. baumannii isolates and dissemination to blood may be dependent on the host’s immune status and the neutrophils phagoburst response.
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27
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Belisario JC, Lee HH, Luknauth H, Rigel NW, Martinez LR. Acinetobacter baumannii Strains Deficient in the Clp Chaperone-Protease Genes Have Reduced Virulence in a Murine Model of Pneumonia. Pathogens 2021; 10:pathogens10020204. [PMID: 33668542 PMCID: PMC7917692 DOI: 10.3390/pathogens10020204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 01/05/2023] Open
Abstract
Acinetobacter baumannii has emerged as a significant opportunistic Gram-negative pathogen and causative agent of nosocomial pneumonia especially in immunocompromised individuals in intensive care units. Recent advances to understand the contribution and function of A. baumannii virulence factors in its pathogenesis have begun to elucidate how this bacterium interacts with immune cells and its interesting mechanisms for multi-antibiotic resistance. Taking advantage of the availability of the A. baumannii AB5075 transposon mutant library, we investigated the impact of the A. baumannii Clp genes, which encode for a chaperone-protease responsible for the degradation of misfolded proteins, on bacterial virulence in a model of pneumonia using C57BL/6 mice and survival within J774.16 macrophage-like cells. Clp-protease A. baumannii mutants exhibit decreased virulence in rodents, high phagocytic cell-mediated killing and reduced biofilm formation. Capsular staining showed evidence of encapsulation in A. baumannii AB5075 and Clp-mutant strains. Surprisingly, clpA and clpS mutants displayed irregular cell morphology, which may be important in the biofilm structural deficiencies observed in these strains. Interestingly, clpA showed apical-like growth, proliferation normally observed in filamentous fungi. These findings provide new information regarding A. baumannii pathogenesis and may be important for the development of therapies intended at reducing morbidity and mortality associated with this remarkable pathogen.
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Affiliation(s)
- J Christian Belisario
- Department of Physical Medicine and Rehabilitation, University of Pennsylvania, Philadelphia, PA 19146, USA;
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA;
| | - Hiu Ham Lee
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA;
| | - Harshani Luknauth
- Department of Biology, Hofstra University, Hempstead, NY 11549, USA; (H.L.); (N.W.R.)
| | - Nathan W. Rigel
- Department of Biology, Hofstra University, Hempstead, NY 11549, USA; (H.L.); (N.W.R.)
| | - Luis R. Martinez
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA;
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, FL 32610, USA
- Correspondence:
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28
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Talyansky Y, Nielsen TB, Yan J, Carlino-Macdonald U, Di Venanzio G, Chakravorty S, Ulhaq A, Feldman MF, Russo TA, Vinogradov E, Luna B, Wright MS, Adams MD, Spellberg B. Capsule carbohydrate structure determines virulence in Acinetobacter baumannii. PLoS Pathog 2021; 17:e1009291. [PMID: 33529209 PMCID: PMC7880449 DOI: 10.1371/journal.ppat.1009291] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 02/12/2021] [Accepted: 01/07/2021] [Indexed: 01/27/2023] Open
Abstract
Acinetobacter baumannii is a highly antibiotic-resistant bacterial pathogen for which novel therapeutic approaches are needed. Unfortunately, the drivers of virulence in A. baumannii remain uncertain. By comparing genomes among a panel of A. baumannii strains we identified a specific gene variation in the capsule locus that correlated with altered virulence. While less virulent strains possessed the intact gene gtr6, a hypervirulent clinical isolate contained a spontaneous transposon insertion in the same gene, resulting in the loss of a branchpoint in capsular carbohydrate structure. By constructing isogenic gtr6 mutants, we confirmed that gtr6-disrupted strains were protected from phagocytosis in vitro and displayed higher bacterial burden and lethality in vivo. Gtr6+ strains were phagocytized more readily and caused lower bacterial burden and no clinical illness in vivo. We found that the CR3 receptor mediated phagocytosis of gtr6+, but not gtr6-, strains in a complement-dependent manner. Furthermore, hypovirulent gtr6+ strains demonstrated increased virulence in vivo when CR3 function was abrogated. In summary, loss-of-function in a single capsule assembly gene dramatically altered virulence by inhibiting complement deposition and recognition by phagocytes across multiple A. baumannii strains. Thus, capsular structure can determine virulence among A. baumannii strains by altering bacterial interactions with host complement-mediated opsonophagocytosis.
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Affiliation(s)
- Yuli Talyansky
- Department of Molecular Microbiology & Immunology, University of Southern California, Los Angeles, California, United States of America
| | - Travis B. Nielsen
- Department of Molecular Microbiology & Immunology, University of Southern California, Los Angeles, California, United States of America
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Jun Yan
- Department of Molecular Microbiology & Immunology, University of Southern California, Los Angeles, California, United States of America
| | - Ulrike Carlino-Macdonald
- Division of Infectious Diseases, Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Veterans Administration, Buffalo, New York, United States of America
| | - Gisela Di Venanzio
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Somnath Chakravorty
- Division of Infectious Diseases, Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Veterans Administration, Buffalo, New York, United States of America
| | - Amber Ulhaq
- Department of Molecular Microbiology & Immunology, University of Southern California, Los Angeles, California, United States of America
| | - Mario F. Feldman
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Thomas A. Russo
- Division of Infectious Diseases, Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Veterans Administration, Buffalo, New York, United States of America
| | - Evgeny Vinogradov
- National Research Council Canada, Human Health Therapeutics Centre, Ottawa, Canada
| | - Brian Luna
- Department of Molecular Microbiology & Immunology, University of Southern California, Los Angeles, California, United States of America
| | - Meredith S. Wright
- Rady Children’s Institute for Genomic Medicine, San Diego, California, United States of America
| | - Mark D. Adams
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, United States of America
| | - Brad Spellberg
- LAC+USC Medical Center, Los Angeles, California, United States of America
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Acinetobacter baumannii Targets Human Carcinoembryonic Antigen-Related Cell Adhesion Molecules (CEACAMs) for Invasion of Pneumocytes. mSystems 2020; 5:5/6/e00604-20. [PMID: 33361319 PMCID: PMC7762790 DOI: 10.1128/msystems.00604-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Multidrug-resistant Acinetobacter baumannii is regarded as a life-threatening pathogen mainly associated with nosocomial and community-acquired pneumonia. Here, we show that A. baumannii can bind the human carcinoembryonic antigen-related cell adhesion molecule (CEACAM) receptors CEACAM1, CEACAM5, and CEACAM6. This specific interaction enhances A. baumannii internalization in membrane-bound vacuoles, promptly decorated with Rab5, Rab7, and lipidated microtubule-associated protein light chain 3 (LC3). Dissecting intracellular signaling pathways revealed that infected pneumocytes trigger interleukin-8 (IL-8) secretion via the extracellular signal-regulated kinase (ERK)1/2 and nuclear factor-kappa B (NF-κB) signaling pathways for A. baumannii clearance. However, in CEACAM1-L-expressing cells, IL-8 secretion lasts only 24 h, possibly due to an A. baumannii-dependent effect on the CEACAM1-L intracellular domain. Conversely, the glycosylphosphatidylinositol-anchored CEACAM5 and CEACAM6 activate the c-Jun NH2-terminal kinase (JNK)1/2-Rubicon-NOX2 pathway, suggestive of LC3-associated phagocytosis. Overall, our data show for the first time novel mechanisms of adhesion to and invasion of pneumocytes by A. baumannii via CEACAM-dependent signaling pathways that eventually lead to bacterial killing. These findings suggest that CEACAM upregulation could put patients at increased risk of lower respiratory tract infection by A. baumannii IMPORTANCE This work shows for the first time that Acinetobacter baumannii binds to carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), CEACAM5, and CEACAM6. This binding significantly enhances A. baumannii internalization within alveolar host cell epithelia. Intracellular trafficking involves typical Rab5 and Rab7 vacuolar proteins as well as light chain 3 (LC3) and slowly progresses to bacterial killing by endosome acidification. CEACAM engagement by A. baumannii leads to distinct and specific downstream signaling pathways. The CEACAM1 pathway finely tunes interleukin-8 (IL-8) secretion, whereas CEACAM5 and CEACAM6 mediate LC3-associated phagocytosis. The present study provides new insights into A. baumannii-host interactions and could represent a promising therapeutic strategy to reduce pulmonary infections caused by this pathogen.
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Ghaly TM, Paulsen IT, Sajjad A, Tetu SG, Gillings MR. A Novel Family of Acinetobacter Mega-Plasmids Are Disseminating Multi-Drug Resistance Across the Globe While Acquiring Location-Specific Accessory Genes. Front Microbiol 2020; 11:605952. [PMID: 33343549 PMCID: PMC7738440 DOI: 10.3389/fmicb.2020.605952] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/10/2020] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter species are emerging as major nosocomial pathogens, aided by their ability to acquire resistance to all classes of antibiotics. A key factor leading to their multi-drug resistance phenotypes is the acquisition of a wide variety of mobile genetic elements, particularly large conjugative plasmids. Here, we characterize a family of 21 multi-drug resistance mega-plasmids in 11 different Acinetobacter species isolated from various locations across the globe. The plasmid family exhibits a highly dynamic and diverse accessory genome, including 221 antibiotic resistance genes (ARGs) that confer resistance to 13 classes of antibiotics. We show that plasmids isolated within the same geographic region are often evolutionarily divergent members of this family based on their core-genome, yet they exhibit a more similar accessory genome. Individual plasmids, therefore, can disseminate to different locations around the globe, where they then appear to acquire diverse sets of accessory genes from their local surroundings. Further, we show that plasmids from several geographic regions were enriched with location-specific functional traits. Together, our findings show that these mega-plasmids can transmit across species boundaries, have the capacity for global dissemination, can accumulate a diverse suite of location-specific accessory genes, and can confer multi-drug resistance phenotypes of significant concern for human health. We therefore highlight this previously undescribed plasmid family as a serious threat to healthcare systems worldwide. These findings also add to the growing concern that mega-plasmids are key disseminators of antibiotic resistance and require global surveillance.
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Affiliation(s)
- Timothy M. Ghaly
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ian T. Paulsen
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW, Australia
| | - Ammara Sajjad
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Sasha G. Tetu
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW, Australia
| | - Michael R. Gillings
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW, Australia
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31
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Delancey E, Allison D, KC HR, Gilmore DF, Fite T, Basnakian AG, Alam MA. Synthesis of 4,4'-(4-Formyl-1 H-pyrazole-1,3-diyl)dibenzoic Acid Derivatives as Narrow Spectrum Antibiotics for the Potential Treatment of Acinetobacter Baumannii Infections. Antibiotics (Basel) 2020; 9:antibiotics9100650. [PMID: 32998384 PMCID: PMC7601628 DOI: 10.3390/antibiotics9100650] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 12/19/2022] Open
Abstract
Acinetobacter baumannii has emerged as one of the most lethal drug-resistant bacteria in recent years. We report the synthesis and antimicrobial studies of 25 new pyrazole-derived hydrazones. Some of these molecules are potent and specific inhibitors of A. baumannii strains with a minimum inhibitory concentration (MIC) value as low as 0.78 µg/mL. These compounds are non-toxic to mammalian cell lines in in vitro studies. Furthermore, one of the potent molecules has been studied for possible in vivo toxicity in the mouse model and found to be non-toxic based on the effect on 14 physiological blood markers of organ injury.
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Affiliation(s)
- Evan Delancey
- Department of Chemistry and Physics, College of Science and Mathematics, Arkansas State University, Jonesboro, AR 72467, USA; (E.D.); (D.A.); (H.R.K.)
| | - Devin Allison
- Department of Chemistry and Physics, College of Science and Mathematics, Arkansas State University, Jonesboro, AR 72467, USA; (E.D.); (D.A.); (H.R.K.)
| | - Hansa Raj KC
- Department of Chemistry and Physics, College of Science and Mathematics, Arkansas State University, Jonesboro, AR 72467, USA; (E.D.); (D.A.); (H.R.K.)
| | - David F. Gilmore
- Department of Biological Sciences, College of Science and Mathematics, Arkansas State University, Jonesboro, AR 72467, USA;
| | - Todd Fite
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR 72205, USA; (T.F.); (A.G.B.)
- Central Arkansas Veterans Healthcare System, W. 7th St., Little Rock, AR 72205, USA
| | - Alexei G. Basnakian
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR 72205, USA; (T.F.); (A.G.B.)
- Central Arkansas Veterans Healthcare System, W. 7th St., Little Rock, AR 72205, USA
| | - Mohammad A. Alam
- Department of Chemistry and Physics, College of Science and Mathematics, Arkansas State University, Jonesboro, AR 72467, USA; (E.D.); (D.A.); (H.R.K.)
- Correspondence: ; Tel.: +1-870-972-3319
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32
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Kon H, Schwartz D, Temkin E, Carmeli Y, Lellouche J. Rapid identification of capsulated Acinetobacter baumannii using a density-dependent gradient test. BMC Microbiol 2020; 20:285. [PMID: 32938408 PMCID: PMC7493399 DOI: 10.1186/s12866-020-01971-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 09/08/2020] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Gram-negative bacterial capsules are associated with production of carbohydrates, frequently resulting in a mucoid phenotype. Infections caused by capsulated or mucoid A. baumannii are associated with increased clinical severity. Therefore, it is clinically and epidemiologically important to identify capsulated A. baumannii. Here, we describe a density-dependent gradient test to distinguish between capsulated and thin/non-capsulated A. baumannii. RESULTS Thirty-one of 57 A. baumannii isolates displayed a mucoid phenotype. The density-dependent gradient test was comprised of two phases, with silica concentrations of 30% (top phase) and 50% (bottom phase). Twenty-three isolates migrated to the bottom phase, indicating thin or non-capsulated strains, and 34 migrated to the top phase, suggesting strains suspected to be capsulated. There was agreement between the mucoid and the non-mucoid phenotypes and the density-dependent gradient test for all but three isolates. Total carbohydrates extracted from strains suspected to be capsulated were significantly higher. Transmission electron microscopy confirmed the presence of a capsule in the six representative strains suspected to be capsulated. CONCLUSIONS The density-dependent gradient test can be used to verify capsule presence in mucoid-appearing A. baumannii strains. Identifying capsulated strains can be useful for directing infection control measures to reduce the spread of hypervirulent strains.
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Affiliation(s)
- Hadas Kon
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel-Aviv Sourasky Medical Center, 6 Weizmann St, 6423906, Tel-Aviv, Israel
| | - David Schwartz
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel-Aviv Sourasky Medical Center, 6 Weizmann St, 6423906, Tel-Aviv, Israel
| | - Elizabeth Temkin
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel-Aviv Sourasky Medical Center, 6 Weizmann St, 6423906, Tel-Aviv, Israel
| | - Yehuda Carmeli
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel-Aviv Sourasky Medical Center, 6 Weizmann St, 6423906, Tel-Aviv, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Jonathan Lellouche
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel-Aviv Sourasky Medical Center, 6 Weizmann St, 6423906, Tel-Aviv, Israel.
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33
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Powers MJ, Simpson BW, Trent MS. The Mla pathway in Acinetobacter baumannii has no demonstrable role in anterograde lipid transport. eLife 2020; 9:56571. [PMID: 32880370 PMCID: PMC7500953 DOI: 10.7554/elife.56571] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 09/02/2020] [Indexed: 12/17/2022] Open
Abstract
The asymmetric outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier to the environment. Perturbations to OM lipid asymmetry sensitize the cell to antibiotics. As such, mechanisms involved in lipid asymmetry are fundamental to our understanding of OM lipid homeostasis. One such mechanism, the Maintenance of lipid asymmetry (Mla) pathway has been proposed to extract mislocalized glycerophospholipids from the outer leaflet of the OM and return them to the inner membrane (IM). Work on this pathway in Acinetobacter baumannii support conflicting models for the directionality of the Mla system being retrograde (OM to IM) or anterograde (IM to OM). Here, we show conclusively that A. baumannii mla mutants exhibit no defects in anterograde transport. Furthermore, we identify an allele of the GTPase obgE that is synthetically sick in the absence of Mla; providing another link between cell envelope homeostasis and stringent response.
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Affiliation(s)
- Matthew J Powers
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, United States.,Department of Microbiology, College of Arts and Sciences, University of Georgia, Athens, United States
| | - Brent W Simpson
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, United States
| | - M Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, United States.,Department of Microbiology, College of Arts and Sciences, University of Georgia, Athens, United States
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Capillary bacterial migration on non-nutritive solid surfaces. Arh Hig Rada Toksikol 2020; 71:251-260. [PMID: 33074174 PMCID: PMC7968502 DOI: 10.2478/aiht-2020-71-3436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 08/01/2020] [Indexed: 12/04/2022] Open
Abstract
Here we describe an additional type of bacterial migration in which bacterial cells migrate vertically across a non-nutritive solid surface carried by capillary forces. Unlike standard motility experiments, these were run on a glass slide inserted into a Falcon tube, partly immersed in a nutrient medium and partly exposed to air. Observations revealed that capillary forces initiated upward cell migration when biofilm was formed at the border between liquid and air. The movement was facilitated by the production of extracellular polymeric substances (EPS). This motility differs from earlier described swarming, twitching, gliding, sliding, or surfing, although these types of movements are not excluded. We therefore propose to call it “capillary movement of biofilm”. This phenomenon may be an ecologically important mode of bacterial motility on solid surfaces.
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35
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Castro-Jaimes S, Bello-López E, Velázquez-Acosta C, Volkow-Fernández P, Lozano-Zarain P, Castillo-Ramírez S, Cevallos MA. Chromosome Architecture and Gene Content of the Emergent Pathogen Acinetobacter haemolyticus. Front Microbiol 2020; 11:926. [PMID: 32670207 PMCID: PMC7326120 DOI: 10.3389/fmicb.2020.00926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/20/2020] [Indexed: 11/25/2022] Open
Abstract
Acinetobacter haemolyticus is a Gammaproteobacterium that has been involved in serious diseases frequently linked to the nosocomial environment. Most of the strains causing such infections are sensitive to a wide variety of antibiotics, but recent reports indicate that this pathogen is acquiring very efficiently carbapenem-resistance determinants like the blaNDM-1 gene, all over the world. With this work we contribute with a collection set of 31 newly sequenced nosocomial A. haemolyticus isolates. Genome analysis of these sequences and others collected from RefSeq indicates that their chromosomes are organized in 12 syntenic blocks that contain most of the core genome genes. These blocks are separated by hypervariable regions that are rich in unique gene families, but also have signals of horizontal gene transfer. Genes involved in virulence or encoding different secretion systems are located inside syntenic regions and have recombination signals. The relative order of the synthetic blocks along the A. haemolyticus chromosome can change, indicating that they have been subject to several kinds of inversions. Genomes of this microorganism show large differences in gene content even if they are in the same clade. Here we also show that A. haemolyticus has an open pan-genome.
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Affiliation(s)
- Semiramis Castro-Jaimes
- Centro de Ciencias Genómicas, Programa de Genómica Evolutiva, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Elena Bello-López
- Centro de Investigaciones en Ciencias Microbiológicas, Posgrado en Microbiología, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | | | | | - Patricia Lozano-Zarain
- Centro de Investigaciones en Ciencias Microbiológicas, Posgrado en Microbiología, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Santiago Castillo-Ramírez
- Centro de Ciencias Genómicas, Programa de Genómica Evolutiva, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Miguel Angel Cevallos
- Centro de Ciencias Genómicas, Programa de Genómica Evolutiva, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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36
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Leal NC, Campos TL, Rezende AM, Docena C, Mendes-Marques CL, de Sá Cavalcanti FL, Wallau GL, Rocha IV, Cavalcanti CLB, Veras DL, Alves LR, Andrade-Figueiredo M, de Barros MPS, de Almeida AMP, de Morais MMC, Leal-Balbino TC, Xavier DE, de-Melo-Neto OP. Comparative Genomics of Acinetobacter baumannii Clinical Strains From Brazil Reveals Polyclonal Dissemination and Selective Exchange of Mobile Genetic Elements Associated With Resistance Genes. Front Microbiol 2020; 11:1176. [PMID: 32655514 PMCID: PMC7326025 DOI: 10.3389/fmicb.2020.01176] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022] Open
Abstract
Acinetobacter baumannii is an opportunistic bacterial pathogen infecting immunocompromised patients and has gained attention worldwide due to its increased antimicrobial resistance. Here, we report a comparative whole-genome sequencing and analysis coupled with an assessment of antibiotic resistance of 46 Acinetobacter strains (45 A. baumannii plus one Acinetobacter nosocomialis) originated from five hospitals from the city of Recife, Brazil, between 2010 and 2014. An average of 3,809 genes were identified per genome, although only 2,006 genes were single copy orthologs or core genes conserved across all sequenced strains, with an average of 42 new genes found per strain. We evaluated genetic distance through a phylogenetic analysis and MLST as well as the presence of antibiotic resistance genes, virulence markers and mobile genetic elements (MGE). The phylogenetic analysis recovered distinct monophyletic A. baumannii groups corresponding to five known (ST1, ST15, ST25, ST79, and ST113) and one novel ST (ST881, related to ST1). A large number of ST specific genes were found, with the ST79 strains having the largest number of genes in common that were missing from the other STs. Multiple genes associated with resistance to β-lactams, aminoglycosides and other antibiotics were found. Some of those were clearly mapped to defined MGEs and an analysis of those revealed known elements as well as a novel Tn7-Tn3 transposon with a clear ST specific distribution. An association of selected resistance/virulence markers with specific STs was indeed observed, as well as the recent spread of the OXA-253 carbapenemase encoding gene. Virulence genes associated with the synthesis of the capsular antigens were noticeably more variable in the ST113 and ST79 strains. Indeed, several resistance and virulence genes were common to the ST79 and ST113 strains only, despite a greater genetic distance between them, suggesting common means of genetic exchange. Our comparative analysis reveals the spread of multiple STs and the genomic plasticity of A. baumannii from different hospitals in a single metropolitan area. It also highlights differences in the spread of resistance markers and other MGEs between the investigated STs, impacting on the monitoring and treatment of Acinetobacter in the ongoing and future outbreaks.
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Affiliation(s)
- Nilma C Leal
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil
| | - Túlio L Campos
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil
| | - Antonio M Rezende
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil
| | - Cássia Docena
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil
| | | | - Felipe L de Sá Cavalcanti
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil.,Department of Pathology, Institute of Biological Sciences, University of Pernambuco, Recife, Brazil
| | - Gabriel L Wallau
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil
| | - Igor V Rocha
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil
| | | | - Dyana L Veras
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil
| | - Lilian R Alves
- Department of Tropical Medicine, Federal University of Pernambuco, Recife, Brazil
| | | | | | | | | | | | - Danilo E Xavier
- Aggeu Magalhães Institute (IAM), Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil
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37
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Zhang L, Fu Y, Han X, Xu Q, Weng S, Yan B, Liu L, Hua X, Chen Y, Yu Y. Phenotypic Variation and Carbapenem Resistance Potential in OXA-499-Producing Acinetobacter pittii. Front Microbiol 2020; 11:1134. [PMID: 32582088 PMCID: PMC7296048 DOI: 10.3389/fmicb.2020.01134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/05/2020] [Indexed: 12/17/2022] Open
Abstract
Acinetobacter pittii is increasingly recognized as a clinically important species. Here, we identified a carbapenem-non-resistant A. pittii clinical isolate, A1254, harboring blaOXA–499, blaOXA–826, and blaADC–221. The blaOXA–499 genetic environment in A1254 was identical to that of another OXA-499-producing, but carbapenem-resistant, A. pittii isolate, YMC2010/8/T346, indicating the existence of phenotypic variation among OXA-499-producing A. pittii strains. Under imipenem-selective pressure, the A1254 isolate developed resistance to carbapenems in 60 generations. Two carbapenem-resistant mutants (CAB009 and CAB010) with mutations in the blaOXA–499 promoter region were isolated from two independently evolved populations (CAB001 and CAB004). The CAB009 mutant, with a mutation at position −14 (A to G), exhibited a four-fold higher carbapenem minimum inhibitory concentration (MIC) and a 4.53 ± 0.19 log2 fold change higher expression level of blaOXA–499 than the ancestor strain, A1254. The other mutant, CAB010, with a mutation at position −42 (G to A), showed a two-fold higher carbapenem MIC and a 1.65 ± 0.25 log2 fold change higher blaOXA–499 expression level than the ancestor strain. The blaOXA–499 gene and its promoter region were amplified from the wild-type strain and two mutant isolates and then individually cloned into the pYMAb2-Hygr vector and expressed in Acinetobacter baumannii ATCC 17978, A. pittii LMG 1035, and A. pittii A1254. All the transformed strains were resistant to carbapenem, irrespective of whether they harbored the initial or an evolved promoter sequence, and transformed strains expressing the promoter from the most resistant mutant, CAB009, showed the highest carbapenem MICs, with values of 32–64 μg/ml for imipenem and 128 μg/ml for meropenem. RNA sequencing was performed to confirm the contribution of blaOXA–499 to the development of carbapenem resistance. Although the CAB009 and CAB010 transcriptional patterns were different, blaOXA–499 was the only differentially expressed gene shared by the two mutants. Our results indicate that carbapenem-non-resistant Acinetobacter spp. strains carrying blaOXA genes have the potential to develop carbapenem resistance and need to be further investigated and monitored to prevent treatment failure due to the development of resistance.
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Affiliation(s)
- Linyue Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Ying Fu
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China.,Department of Clinical Laboratory, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Xinhong Han
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Qingye Xu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Shanshan Weng
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Biyong Yan
- Department of Laboratory Medicine, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Lilin Liu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Xiaoting Hua
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Yan Chen
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
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Ramirez MS, Bonomo RA, Tolmasky ME. Carbapenemases: Transforming Acinetobacter baumannii into a Yet More Dangerous Menace. Biomolecules 2020; 10:biom10050720. [PMID: 32384624 PMCID: PMC7277208 DOI: 10.3390/biom10050720] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 02/07/2023] Open
Abstract
Acinetobacter baumannii is a common cause of serious nosocomial infections. Although community-acquired infections are observed, the vast majority occur in people with preexisting comorbidities. A. baumannii emerged as a problematic pathogen in the 1980s when an increase in virulence, difficulty in treatment due to drug resistance, and opportunities for infection turned it into one of the most important threats to human health. Some of the clinical manifestations of A. baumannii nosocomial infection are pneumonia; bloodstream infections; lower respiratory tract, urinary tract, and wound infections; burn infections; skin and soft tissue infections (including necrotizing fasciitis); meningitis; osteomyelitis; and endocarditis. A. baumannii has an extraordinary genetic plasticity that results in a high capacity to acquire antimicrobial resistance traits. In particular, acquisition of resistance to carbapenems, which are among the antimicrobials of last resort for treatment of multidrug infections, is increasing among A. baumannii strains compounding the problem of nosocomial infections caused by this pathogen. It is not uncommon to find multidrug-resistant (MDR, resistance to at least three classes of antimicrobials), extensively drug-resistant (XDR, MDR plus resistance to carbapenems), and pan-drug-resistant (PDR, XDR plus resistance to polymyxins) nosocomial isolates that are hard to treat with the currently available drugs. In this article we review the acquired resistance to carbapenems by A. baumannii. We describe the enzymes within the OXA, NDM, VIM, IMP, and KPC groups of carbapenemases and the coding genes found in A. baumannii clinical isolates.
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Affiliation(s)
- Maria Soledad Ramirez
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA 92831, USA;
| | - Robert A. Bonomo
- Medical Service and GRECC, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH 44106, USA;
- Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Biochemistry, Proteomics and Bioinformatics; Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- WRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH 44106, USA
| | - Marcelo E. Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA 92831, USA;
- Correspondence: ; Tel.: +657-278-5263
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Genetic mechanisms of antibiotic resistance and virulence in Acinetobacter baumannii: background, challenges and future prospects. Mol Biol Rep 2020; 47:4037-4046. [PMID: 32303957 DOI: 10.1007/s11033-020-05389-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 03/24/2020] [Indexed: 01/18/2023]
Abstract
With the advent of the multidrug-resistant era, many opportunistic pathogens including the species Acinetobacter baumannii have gained prominence and pose a major global threat to clinical health care. Pathogenicity in bacteria is genetically regulated by a complex network of transcription and virulence factors and a brief overview of the major investigations on comprehending these processes over the past few decades in A. baumanni are compiled here. Many investigators have employed genome sequencing techniques to identify the regions that contribute to antibiotic resistance and comparative genomics to study sequence similarities to understand evolutionary trends of resistance gene transfers between isolates. A summary of these studies given here provides an insight into the invasion and successful colonization of the species. The individual roles played by different genes, regulators & promoters, enzymes, metal ions as well as mobile elements in influencing antibiotic resistance are briefly discussed. Precautionary measures and prospects for developing future strategies by exploring promising new research targets in effective control of multidrug resistant A. baumannii are also analyzed.
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40
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Loraine J, Heinz E, Soontarach R, Blackwell GA, Stabler RA, Voravuthikunchai SP, Srimanote P, Kiratisin P, Thomson NR, Taylor PW. Genomic and Phenotypic Analyses of Acinetobacter baumannii Isolates From Three Tertiary Care Hospitals in Thailand. Front Microbiol 2020; 11:548. [PMID: 32328045 PMCID: PMC7153491 DOI: 10.3389/fmicb.2020.00548] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/13/2020] [Indexed: 12/24/2022] Open
Abstract
Antibiotic resistant strains of Acinetobacter baumannii are responsible for a large and increasing burden of nosocomial infections in Thailand and other countries of Southeast Asia. New approaches to their control and treatment are urgently needed and an attractive strategy is to remove the bacterial polysaccharide capsule, and thus the protection from the host's immune system. To examine phylogenetic relationships, distribution of capsule chemotypes, acquired antibiotic resistance determinants, susceptibility to complement and other traits associated with systemic infection, we sequenced 191 isolates from three tertiary referral hospitals in Thailand and used phenotypic assays to characterize key aspects of infectivity. Several distinct lineages were circulating in three hospitals and the majority belonged to global clonal group 2 (GC2). Very high levels of resistance to carbapenems and other front-line antibiotics were found, as were a number of widespread plasmid replicons. A high diversity of capsule genotypes was encountered, with only three of these (KL6, KL10, and KL47) showing more than 10% frequency. Almost 90% of GC2 isolates belonged to the most common capsule genotypes and were fully resistant to the bactericidal action of human serum complement, most likely protected by their polysaccharide capsule, which represents a key determinant of virulence for systemic infection. Our study further highlights the importance to develop therapeutic strategies to remove the polysaccharide capsule from extensively drug-resistant A. baumanii during the course of systemic infection.
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Affiliation(s)
- Jessica Loraine
- School of Pharmacy, University College London, London, United Kingdom
| | - Eva Heinz
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom
| | | | - Grace A Blackwell
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom.,European Bioinformatics Institute, European Molecular Biology Laboratory, Hinxton, Cambridge, United Kingdom
| | - Richard A Stabler
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Potjanee Srimanote
- Faculty of Allied Health Sciences, Thammasat University, Pathumtanee, Thailand
| | | | - Nicholas R Thomson
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom.,London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Peter W Taylor
- School of Pharmacy, University College London, London, United Kingdom
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Cameranesi MM, Paganini J, Limansky AS, Moran-Barrio J, Salcedo SP, Viale AM, Repizo GD. Acquisition of plasmids conferring carbapenem and aminoglycoside resistance and loss of surface-exposed macromolecule structures as strategies for the adaptation of Acinetobacter baumannii CC104 O/CC15 P strains to the clinical setting. Microb Genom 2020; 6. [PMID: 32213259 PMCID: PMC7643966 DOI: 10.1099/mgen.0.000360] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Acinetobacter baumannii (Aba) is an emerging opportunistic pathogen associated to nosocomial infections. The rapid increase in multidrug resistance (MDR) among Aba strains underscores the urgency of understanding how this pathogen evolves in the clinical environment. We conducted here a whole-genome sequence comparative analysis of three phylogenetically and epidemiologically related MDR Aba strains from Argentinean hospitals, assigned to the CC104O/CC15P clonal complex. While the Ab244 strain was carbapenem-susceptible, Ab242 and Ab825, isolated after the introduction of carbapenem therapy, displayed resistance to these last resource β-lactams. We found a high chromosomal synteny among the three strains, but significant differences at their accessory genomes. Most importantly, carbapenem resistance in Ab242 and Ab825 was attributed to the acquisition of a Rep_3 family plasmid carrying a blaOXA-58 gene. Other differences involved a genomic island carrying resistance to toxic compounds and a Tn10 element exclusive to Ab244 and Ab825, respectively. Also remarkably, 44 insertion sequences (ISs) were uncovered in Ab825, in contrast with the 14 and 11 detected in Ab242 and Ab244, respectively. Moreover, Ab825 showed a higher killing capacity as compared to the other two strains in the Galleria mellonella infection model. A search for virulence and persistence determinants indicated the loss or IS-mediated interruption of genes encoding many surface-exposed macromolecules in Ab825, suggesting that these events are responsible for its higher relative virulence. The comparative genomic analyses of the CC104O/CC15P strains conducted here revealed the contribution of acquired mobile genetic elements such as ISs and plasmids to the adaptation of A. baumannii to the clinical setting.
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Affiliation(s)
- María M Cameranesi
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Julian Paganini
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Adriana S Limansky
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Jorgelina Moran-Barrio
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Suzana P Salcedo
- Laboratory of Molecular Microbiology and Structural Biochemistry, CNRS UMR5086, University of Lyon, LyonF-69367, France
| | - Alejandro M Viale
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Guillermo D Repizo
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.,Laboratory of Molecular Microbiology and Structural Biochemistry, CNRS UMR5086, University of Lyon, LyonF-69367, France
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42
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El-Khatib L, Al-Dalain S, Al-Matarneh R, Al-Bustanji S, Al-Dmour M, Al-Amarin Y, Gaber Y. Prevalence of Multi-drug Resistant Acinetobacter baumannii (MDRAB) in Amman Jordan During 2018. Infect Disord Drug Targets 2019; 21:105-111. [PMID: 31823709 DOI: 10.2174/1871526519666191211144344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/23/2019] [Accepted: 12/03/2019] [Indexed: 11/22/2022]
Abstract
PURPOSE Acinetobacter baumannii is an opportunistic pathogen, and is among the most problematic nosocomial infections as well as community-acquired infections. This retrospective study was conducted as an attempt to determine the prevalence of multidrug-resistant A. baumannii (MDRAB) isolates from the north and central Jordan area during 2018. METHODS Patients' records provided by an accredited central private laboratory located in Amman, were examined for A. baumannii isolates identified during this period. The isolates were identified to the species level using the API-10S system and the antimicrobial sensitivity testing was determined using the Kirby-Bauer disc diffusion method. RESULTS A total of 43 unduplicated isolates were obtained and classified according to clinical sampling source into: Group I (blood), Group II (urine) and Group III (wound, pus, sputum, bedsore and others). Total MDRAB isolates recorded were 29 (67.4 %). Resistance to imipenem was found to be 36% and 94% among groups II and III, respectively, and resistance to meropenem was 60% and 88% among the same groups, respectively. CONCLUSION Antimicrobial stewardship programs at a national scale are needed to calculate the actual proportion of MDRAB in the country and to combat its increasing emergence and decrease the magnitude of antibiotic resistance.
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Affiliation(s)
- Layla El-Khatib
- Department of Biological Sciences, School of Science, The University of Jordan, Amman, 11942, Jordan
| | - Saed Al-Dalain
- Department of Pharmacology, Faculty of Medicine, Mutah University, Al-Karak, 61710, Jordan
| | - Rama Al-Matarneh
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Mutah University, Al-Karak, 61710, Jordan
| | - Sara Al-Bustanji
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Mutah University, Al-Karak, 61710, Jordan
| | - Marwa Al-Dmour
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Mutah University, Al-Karak, 61710, Jordan
| | - Yara Al-Amarin
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Mutah University, Al-Karak, 61710, Jordan
| | - Yasser Gaber
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Mutah University, Al-Karak, 61710, Jordan
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43
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Dual Role of gnaA in Antibiotic Resistance and Virulence in Acinetobacter baumannii. Antimicrob Agents Chemother 2019; 63:AAC.00694-19. [PMID: 31358579 DOI: 10.1128/aac.00694-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/11/2019] [Indexed: 12/12/2022] Open
Abstract
Acinetobacter baumannii is an important Gram-negative pathogen in hospital-related infections. However, treatment options for A. baumannii infections have become limited due to multidrug resistance. Bacterial virulence is often associated with capsule genes found in the K locus, many of which are essential for biosynthesis of the bacterial envelope. However, the roles of other genes in the K locus remain largely unknown. From an in vitro evolution experiment, we obtained an isolate of the virulent and multidrug-resistant A. baumannii strain MDR-ZJ06, called MDR-ZJ06M, which has an insertion by the ISAba16 transposon in gnaA (encoding UDP-N-acetylglucosamine C-6 dehydrogenase), a gene found in the K locus. The isolate showed an increased resistance toward tigecycline, whereas the MIC decreased in the case of carbapenems, cephalosporins, colistin, and minocycline. By using knockout and complementation experiments, we demonstrated that gnaA is important for the synthesis of lipooligosaccharide and capsular polysaccharide and that disruption of the gene affects the morphology, drug susceptibility, and virulence of the pathogen.
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44
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Geisinger E, Huo W, Hernandez-Bird J, Isberg RR. Acinetobacter baumannii: Envelope Determinants That Control Drug Resistance, Virulence, and Surface Variability. Annu Rev Microbiol 2019; 73:481-506. [DOI: 10.1146/annurev-micro-020518-115714] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Acinetobacter baumannii has emerged as an important nosocomial pathogen, particularly for patients in intensive care units and with invasive indwelling devices. The most recent clinical isolates are resistant to several classes of clinically important antibiotics, greatly restricting the ability to effectively treat critically ill patients. The bacterial envelope is an important driver of A. baumannii disease, both at the level of battling against antibiotic therapy and at the level of protecting from host innate immune function. This review provides a comprehensive overview of key features of the envelope that interface with both the host and antimicrobial therapies. Carbohydrate structures that contribute to protecting from the host are detailed, and mutations that alter these structures, resulting in increased antimicrobial resistance, are explored. In addition, protein complexes involved in both intermicrobial and host-microbe interactions are described. Finally we discuss regulatory mechanisms that control the nature of the cell envelope and its impact on host innate immune function.
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Affiliation(s)
- Edward Geisinger
- Department of Biology, Northeastern University, Boston, Massachusetts 02115, USA
| | - Wenwen Huo
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Juan Hernandez-Bird
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Ralph R. Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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45
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Morris FC, Dexter C, Kostoulias X, Uddin MI, Peleg AY. The Mechanisms of Disease Caused by Acinetobacter baumannii. Front Microbiol 2019; 10:1601. [PMID: 31379771 PMCID: PMC6650576 DOI: 10.3389/fmicb.2019.01601] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 06/26/2019] [Indexed: 01/29/2023] Open
Abstract
Acinetobacter baumannii is a Gram negative opportunistic pathogen that has demonstrated a significant insurgence in the prevalence of infections over recent decades. With only a limited number of “traditional” virulence factors, the mechanisms underlying the success of this pathogen remain of great interest. Major advances have been made in the tools, reagents, and models to study A. baumannii pathogenesis, and this has resulted in a substantial increase in knowledge. This article provides a comprehensive review of the bacterial virulence factors, the host immune responses, and animal models applicable for the study of this important human pathogen. Collating the most recent evidence characterizing bacterial virulence factors, their cellular targets and genetic regulation, we have encompassed numerous aspects important to the success of this pathogen, including membrane proteins and cell surface adaptations promoting immune evasion, mechanisms for nutrient acquisition and community interactions. The role of innate and adaptive immune responses is reviewed and areas of paucity in our understanding are highlighted. Finally, with the vast expansion of available animal models over recent years, we have evaluated those suitable for use in the study of Acinetobacter disease, discussing their advantages and limitations.
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Affiliation(s)
- Faye C Morris
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Carina Dexter
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Xenia Kostoulias
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Muhammad Ikhtear Uddin
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Anton Y Peleg
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, VIC, Australia
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46
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Martin SE, Melander RJ, Brackett CM, Scott AJ, Chandler CE, Nguyen CM, Minrovic BM, Harrill SE, Ernst RK, Manoil C, Melander C. Small Molecule Potentiation of Gram-Positive Selective Antibiotics against Acinetobacter baumannii. ACS Infect Dis 2019; 5:1223-1230. [PMID: 31002491 DOI: 10.1021/acsinfecdis.9b00067] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In 2016, the World Health Organization deemed antibiotic resistance one of the biggest threats to global health, food security, and development. The need for new methods to combat infections caused by antibiotic resistant pathogens will require a variety of approaches to identifying effective new therapeutic strategies. One approach is the identification of small molecule adjuvants that potentiate the activity of antibiotics of demonstrated utility, whose efficacy is abated by resistance, both acquired and intrinsic. To this end, we have identified compounds that enhance the efficacy of antibiotics normally ineffective against Gram-negative pathogens because of the outer membrane permeability barrier. We identified two adjuvant compounds that dramatically enhance sensitivity of Acinetobacter baumannii to macrolide and glycopeptide antibiotics, with reductions in minimum inhibitory concentrations as high as 256-fold, and we observed activity across a variety of clinical isolates. Mode of action studies indicate that these adjuvants likely work by modulating lipopolysaccharide synthesis or assembly. The adjuvants were active in vivo in a Galleria mellonella infection model, indicating potential for use in mammalian infections.
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Affiliation(s)
- Sara E. Martin
- Department of Chemistry and Biochemistry, University of Notre Dame, 236 Cavanaugh Drive, Notre Dame, Indiana 46556, United States
| | - Roberta J. Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, 236 Cavanaugh Drive, Notre Dame, Indiana 46556, United States
| | - Christopher M. Brackett
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, United States
| | - Alison J. Scott
- Department of Microbial Pathogenesis, University of Maryland—Baltimore, 650 West Baltimore Street, Room 8203, Baltimore, Maryland 21201, United States
| | - Courtney E. Chandler
- Department of Microbial Pathogenesis, University of Maryland—Baltimore, 650 West Baltimore Street, Room 8203, Baltimore, Maryland 21201, United States
| | - Catherine M. Nguyen
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, United States
| | - Bradley M. Minrovic
- Department of Chemistry and Biochemistry, University of Notre Dame, 236 Cavanaugh Drive, Notre Dame, Indiana 46556, United States
| | - Sarah E. Harrill
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, United States
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, University of Maryland—Baltimore, 650 West Baltimore Street, Room 8203, Baltimore, Maryland 21201, United States
| | - Colin Manoil
- Department of Genome Sciences, University of Washington, Foege Building S-250, Box 355065, 3720 15th Ave NE, Seattle, Washington 98195, United States
| | - Christian Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, 236 Cavanaugh Drive, Notre Dame, Indiana 46556, United States
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47
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Schramm STJ, Place K, Montaña S, Almuzara M, Fung S, Fernandez JS, Tuttobene MR, Golic A, Altilio M, Traglia GM, Vay C, Mussi MA, Iriarte A, Ramirez MS. Genetic and Phenotypic Features of a Novel Acinetobacter Species, Strain A47, Isolated From the Clinical Setting. Front Microbiol 2019; 10:1375. [PMID: 31275288 PMCID: PMC6591377 DOI: 10.3389/fmicb.2019.01375] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/03/2019] [Indexed: 11/13/2022] Open
Abstract
In 2014, a novel species of Acinetobacter, strain A47, determined to be hospital-acquired was recovered from a single patient soft tissue sample following a traumatic accident. The complexity of the Acinetobacter genus has been established, and every year novel species are identified. However, specific features and virulence factors that allow members of this genus to be successful pathogens are not well understood. Utilizing both genomic and phenotypic approaches, we identified distinct features and potential virulence factors of the A47 strain to understand its pathobiology. In silico analyses confirmed the uniqueness of this strain and other comparative and sequence analyses were used to study the evolution of relevant features identified in this isolate. The A47 genome was further analyzed for genes associated with virulence and genes involved in type IV pili (T4P) biogenesis, hemolysis, type VI secretion system (T6SS), and novel antibiotic resistance determinants were identified. A47 exhibited natural transformation with both genomic and plasmid DNA. It was able to form biofilms on different surfaces, to cause hemolysis of sheep and rabbit erythrocytes, and to kill competitor bacteria. Additionally, surface structures with non-uniform length were visualized with scanning electron microscopy and proposed as pili-like structures. Furthermore, the A47 genome revealed the presence of two putative BLUF type photoreceptors, and phenotypic assays confirmed the modulation by light of different virulence traits. Taken together, these results provide insight into the pathobiology of A47, which exhibits multiple virulence factors, natural transformation, and the ability to sense and respond to light, which may contribute to the success of an A47 as a hospital dwelling pathogen.
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Affiliation(s)
- Sareda T. J. Schramm
- Department of Biological Science, California State University Fullerton, Fullerton, CA, United States
| | - Kori Place
- Department of Biological Science, California State University Fullerton, Fullerton, CA, United States
| | - Sabrina Montaña
- Facultad de Medicina, Instituto de Microbiología y Parasitología Médica (IMPaM, UBA-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Marisa Almuzara
- Laboratorio de Bacteriología Clínica, Departamento de Bioquímica Clínica, Hosp. de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Sammie Fung
- Department of Biological Science, California State University Fullerton, Fullerton, CA, United States
| | - Jennifer S. Fernandez
- Department of Biological Science, California State University Fullerton, Fullerton, CA, United States
| | - Marisel R. Tuttobene
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI – CONICET), Rosario, Argentina
| | - Adrián Golic
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI – CONICET), Rosario, Argentina
| | - Matías Altilio
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI – CONICET), Rosario, Argentina
| | - German M. Traglia
- Laboratorio de Bacteriología Clínica, Departamento de Bioquímica Clínica, Hosp. de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Carlos Vay
- Laboratorio de Bacteriología Clínica, Departamento de Bioquímica Clínica, Hosp. de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Maria Alejandra Mussi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI – CONICET), Rosario, Argentina
| | - Andres Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Maria Soledad Ramirez
- Department of Biological Science, California State University Fullerton, Fullerton, CA, United States
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48
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Bolourchi N, Shahcheraghi F, Shirazi AS, Janani A, Bahrami F, Badmasti F. Immunogenic reactivity of recombinant PKF and AbOmpA proteins as serum resistance factors against sepsis of Acinetobacter baumannii. Microb Pathog 2019; 131:9-14. [DOI: 10.1016/j.micpath.2019.03.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 03/23/2019] [Accepted: 03/25/2019] [Indexed: 01/20/2023]
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49
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The Mutation of Conservative Asp268 Residue in the Peptidoglycan-Associated Domain of the OmpA Protein Affects Multiple Acinetobacter baumannii Virulence Characteristics. Molecules 2019; 24:molecules24101972. [PMID: 31121924 PMCID: PMC6572160 DOI: 10.3390/molecules24101972] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/07/2019] [Accepted: 05/20/2019] [Indexed: 12/21/2022] Open
Abstract
Acinetobacter baumannii is a nosocomial human pathogen of increasing concern due to its multidrug resistance profile. The outer membrane protein A (OmpA) is an abundant bacterial cell surface component involved in A. baumannii pathogenesis. It has been shown that the C-terminal domain of OmpA is located in the periplasm and non-covalently associates with the peptidoglycan layer via two conserved amino acids, thereby anchoring OmpA to the cell wall. Here, we investigated the role of one of the respective residues, D268 in OmpA of A. baumannii clinical strain Ab169, on its virulence characteristics by complementing the ΔompA mutant with the plasmid-borne ompAD268A allele. We show that while restoring the impaired biofilm formation of the ΔompA strain, the Ab169ompAD268A mutant tended to form bacterial filaments, indicating the abnormalities in cell division. Moreover, the Ab169 OmpA D268-mediated association to peptidoglycan was required for the manifestation of twitching motility, desiccation resistance, serum-induced killing, adhesion to epithelial cells and virulence in a nematode infection model, although it was dispensable for the uptake of β-lactam antibiotics by outer membrane vesicles. Overall, the results of this study demonstrate that the OmpA C-terminal domain-mediated association to peptidoglycan is critical for a number of virulent properties displayed by A. baumannii outside and within the host.
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Meshkat Z, Amini Y, Sadeghian H, Salimizand H. ISAba1/bla OXA-23-like family is the predominant cause of carbapenem resistance in Acinetobacter baumannii and Acinetobacter nosocomialis in Iran. INFECTION GENETICS AND EVOLUTION 2019; 71:60-66. [PMID: 30902743 DOI: 10.1016/j.meegid.2019.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 03/15/2019] [Accepted: 03/15/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Zahra Meshkat
- Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Microbiology and Virology, Medical School, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Yousef Amini
- Department of Microbiology, Medical School, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Hamid Sadeghian
- Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Laboratory Sciences, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Himen Salimizand
- Liver and Digestive Research Center, Kurdistan University of Medical Sciences, Sanandaj, Iran; Department of Microbiology, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran.
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