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Lucidi M, Visaggio D, Migliaccio A, Capecchi G, Visca P, Imperi F, Zarrilli R. Pathogenicity and virulence of Acinetobacter baumannii: Factors contributing to the fitness in healthcare settings and the infected host. Virulence 2024; 15:2289769. [PMID: 38054753 PMCID: PMC10732645 DOI: 10.1080/21505594.2023.2289769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 11/27/2023] [Indexed: 12/07/2023] Open
Abstract
Acinetobacter baumannii is a common cause of healthcare-associated infections and hospital outbreaks, particularly in intensive care units. Much of the success of A. baumannii relies on its genomic plasticity, which allows rapid adaptation to adversity and stress. The capacity to acquire novel antibiotic resistance determinants and the tolerance to stresses encountered in the hospital environment promote A. baumannii spread among patients and long-term contamination of the healthcare setting. This review explores virulence factors and physiological traits contributing to A. baumannii infection and adaptation to the hospital environment. Several cell-associated and secreted virulence factors involved in A. baumannii biofilm formation, cell adhesion, invasion, and persistence in the host, as well as resistance to xeric stress imposed by the healthcare settings, are illustrated to give reasons for the success of A. baumannii as a hospital pathogen.
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Affiliation(s)
- Massimiliano Lucidi
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
| | - Daniela Visaggio
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | | | | | - Paolo Visca
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | - Francesco Imperi
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | - Raffaele Zarrilli
- Department of Public Health, University of Naples Federico II, Naples, Italy
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2
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Tayabali AF, Dirieh Y, Groulx E, Elfarawi N, Di Fruscio S, Melanson K, Moteshareie H, Al-Gafari M, Navarro M, Bernatchez S, Demissie Z, Anoop V. Survival and virulence of Acinetobacter baumannii in microbial mixtures. BMC Microbiol 2024; 24:324. [PMID: 39243004 PMCID: PMC11378493 DOI: 10.1186/s12866-024-03471-6] [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: 05/28/2024] [Accepted: 08/20/2024] [Indexed: 09/09/2024] Open
Abstract
Acinetobacter species such as A. venetianus and A. guillouiae have been studied for various biotechnology applications, including bioremediation of recalcitrant and harmful environmental contaminants, as well as bioengineering of enzymes and diagnostic materials. Bacteria used in biotechnology are often combined with other microorganisms in mixtures to formulate efficacious commercial products. However, if the mixture contained a closely related Acinetobacter pathogen such as A. baumannii (Ab), it remains unclear whether the survival and virulence of Ab would be masked or augmented. This uncertainty poses a challenge in ensuring the safety of such biotechnology products, since Ab is one of the most significant pathogens for both hospital and community -acquired infections. This research aimed to investigate the growth and virulence of Ab within a mixture of 11 bacterial species formulated as a mock microbial mixture (MM). Growth challenges with environmental stressors (i.e., temperature, pH, sodium, iron, and antibiotics) revealed that Ab could thrive under diverse conditions except in the presence of ciprofloxacin. When cultured alone, Ab exhibited significantly more growth in the presence of almost all the environmental stressors than when it was co-incubated with the MM. During the exposure of A549 lung epithelial cells to the MM, Ab growth was stimulated compared to that in standard mammalian culture media. Cytotoxicity caused by Ab was suppressed in the presence of the MM. Lymphocytes were significantly reduced in mice exposed to Ab with or without MM via intravenous injection. The levels of the splenic cytokines IL-1α, IL-1β, MCP-1, and MIP-1α were significantly reduced 24 h after exposure to Ab + MM. This study demonstrated that the presence of the MM marginally but significantly reduced the growth and virulence of Ab, which has implications for the safety of mixtures of microorganisms for biotechnological applications. Furthermore, these findings expand our understanding of the virulence of Ab during host-pathogen interactions.
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Affiliation(s)
- Azam F Tayabali
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada.
| | - Yasmine Dirieh
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Emma Groulx
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Nusaybah Elfarawi
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Sabrina Di Fruscio
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Kristina Melanson
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Houman Moteshareie
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Mustafa Al-Gafari
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Martha Navarro
- Scientific Services Division, Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Stéphane Bernatchez
- Biotechnology Sections 1 and 2, New Substances Assessment and Control Bureau, Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Zerihun Demissie
- Biotechnology Sections 1 and 2, New Substances Assessment and Control Bureau, Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Valar Anoop
- Biotechnology Sections 1 and 2, New Substances Assessment and Control Bureau, Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, K1A 0K9, Canada
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Xu Y, Zhu F, Zhou Z, Ma S, Zhang P, Tan C, Luo Y, Qin R, Chen J, Pan P. A novel mRNA multi-epitope vaccine of Acinetobacter baumannii based on multi-target protein design in immunoinformatic approach. BMC Genomics 2024; 25:791. [PMID: 39160492 PMCID: PMC11334330 DOI: 10.1186/s12864-024-10691-7] [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: 05/13/2024] [Accepted: 08/06/2024] [Indexed: 08/21/2024] Open
Abstract
Acinetobacter baumannii is a gram-negative bacillus prevalent in nature, capable of thriving under various environmental conditions. As an opportunistic pathogen, it frequently causes nosocomial infections such as urinary tract infections, bacteremia, and pneumonia, contributing to increased morbidity and mortality in clinical settings. Consequently, developing novel vaccines against Acinetobacter baumannii is of utmost importance. In our study, we identified 10 highly conserved antigenic proteins from the NCBI and UniProt databases for epitope mapping. We subsequently screened and selected 8 CTL, HTL, and LBL epitopes, integrating them into three distinct vaccines constructed with adjuvants. Following comprehensive evaluations of immunological and physicochemical parameters, we conducted molecular docking and molecular dynamics simulations to assess the efficacy and stability of these vaccines. Our findings indicate that all three multi-epitope mRNA vaccines designed against Acinetobacter baumannii are promising; however, further animal studies are required to confirm their reliability and effectiveness.
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Affiliation(s)
- Yizhong Xu
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fei Zhu
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ziyou Zhou
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shiyang Ma
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Peipei Zhang
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Caixia Tan
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yuying Luo
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Rongliu Qin
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jie Chen
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China.
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China.
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | - Pinhua Pan
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China.
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China.
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.
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Pereira IL, Cardoso TL, Wozeak DR, Caballero PS, Buchhorn de Freitas S, Pinto Seixas Neto AC, da Silva Pinto L, Hartwig DD. Antibodies anti-rFilF protein has anti-biofilm activity against carbapenem-resistant Acinetobacter baumannii. Microbes Infect 2024; 26:105347. [PMID: 38679227 DOI: 10.1016/j.micinf.2024.105347] [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: 09/26/2023] [Accepted: 04/22/2024] [Indexed: 05/01/2024]
Abstract
Acinetobacter baumannii is an opportunistic bacterium that causes infection in several sites. Carbapenem-resistant A. baumannii strains (CRAb) lead the World Health Organization's list of 12 pathogens considered a priority for developing new antimicrobials. The pathogenicity of A. baumannii is related to the different virulence factors employed in the colonization of biotic and abiotic surfaces, biofilm formation and multidrug resistance. We analyze the outer membrane protein FilF from A. baumannii in silico and produce it in recombinant form (rFilF). rFilF protein was successfully expressed in Escherichia coli BL21 Star in an insoluble form. Immunization with rFilF induced significant anti-rFilF IgG antibody production in mice, detected by indirect enzyme-linked immunosorbent assay, since the first evaluation until 49th. On the last experimentation day, the predominant immunoglobulin found was IgG1 followed by IgG2a, IgG2b, IgM, IgG3, and IgA. We observe that interleukins 4 and 10 show significant production after the 28th day of experimentation in mice immunized with rFilF. Anti-rFilF pAbs were able to inhibit biofilm formation in nine CRAb strains evaluated, and in the standard strain ATCC® 19606. These results demonstrate the anti-biofilm activity of anti-rFilF antibodies, promising in the development of a non-antibiotic approach based on the control of CRAb strains.
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Affiliation(s)
- Isabel Ladeira Pereira
- Biotechnology Unit, Center of Technological Development, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil
| | - Thayná Laner Cardoso
- Biotechnology Unit, Center of Technological Development, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil
| | - Daniela Rodriguero Wozeak
- Biotechnology Unit, Center of Technological Development, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil
| | - Pamela Scaraffuni Caballero
- Biotechnology Unit, Center of Technological Development, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil
| | - Stella Buchhorn de Freitas
- Biotechnology Unit, Center of Technological Development, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil
| | - Amilton Clair Pinto Seixas Neto
- Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil
| | - Luciano da Silva Pinto
- Biotechnology Unit, Center of Technological Development, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil
| | - Daiane Drawanz Hartwig
- Biotechnology Unit, Center of Technological Development, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil; Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil.
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5
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Uc-Cachón AH, Dzul-Beh A, González-Cortázar M, Zamilpa-Álvarez A, Molina-Salinas GM. Investigating the anti-growth, anti-resistance, and anti-virulence activities of Schoepfia schreberi J.F.Gmel. against the superbug Acinetobacter baumannii. Heliyon 2024; 10:e31420. [PMID: 38813144 PMCID: PMC11133943 DOI: 10.1016/j.heliyon.2024.e31420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/31/2024] Open
Abstract
Schoepfia schreberi has been used in Mayan folk medicine to treat diarrhea and cough. This study aimed to determine the anti-growth, anti-resistance, and/or anti-virulence activities of S. schreberi extracts against Acinetobacter baumannii, a pathogen leader that causes healthcare-associated infections with high rates of drug-resistant including carbapenems, the last line of antibiotics known as superbugs, and analyze their composition using HPLC-DAD. Ethyl acetate (SSB-3) and methanol (SSB-4) bark extracts exhibit antimicrobial and biocidal effects against drug-susceptible and drug-resistant A. baumannii. Chemical analysis revealed that SSB-3 and SSB-4 contained of gallic and ellagic acids derivatives. The anti-resistance activity of the extracts revealed that SSB-3 or SSB-4, combined with imipenem, exhibited potent antibiotic reversal activity against A. baumannii by acting as pump efflux modulators. The extracts also displayed activity against surface motility of A. baumannii and its capacity to survive reactive oxygen species. This study suggests that S. schreberi can be considered a source of antibiotics, even adjuvanted compounds, as anti-resistant or anti-virulence agents against A. baumannii, contributing to ethnopharmacological knowledge and reappraisal of Mayan medicinal flora, and supporting the traditional use of the bark of the medicinal plant S. schreberi for the treatment of infectious diseases.
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Affiliation(s)
- Andrés Humberto Uc-Cachón
- Unidad de Investigación Médica Yucatán, Instituto Mexicano del Seguro Social, Mérida, 97150, Yucatán, Mexico
| | - Angel Dzul-Beh
- Unidad de Investigación Médica Yucatán, Instituto Mexicano del Seguro Social, Mérida, 97150, Yucatán, Mexico
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, 11340, Mexico
| | - Manases González-Cortázar
- Centro de Investigación Biomédica del Sur, Instituto Mexicano del Seguro Social, Xochitepec, 62790, Morelos, Mexico
| | - Alejandro Zamilpa-Álvarez
- Centro de Investigación Biomédica del Sur, Instituto Mexicano del Seguro Social, Xochitepec, 62790, Morelos, Mexico
| | - Gloria María Molina-Salinas
- Unidad de Investigación Médica Yucatán, Instituto Mexicano del Seguro Social, Mérida, 97150, Yucatán, Mexico
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Claudia MV, Javiera AA, Sebastián NS, José FR, Gloria L. Interplay between desiccation and oxidative stress responses in iron-oxidizing acidophilic bacteria. J Biotechnol 2024; 383:64-72. [PMID: 38311245 DOI: 10.1016/j.jbiotec.2024.01.017] [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: 07/17/2023] [Revised: 01/15/2024] [Accepted: 01/30/2024] [Indexed: 02/10/2024]
Abstract
Variations in water availability represent a foremost stress factor affecting the growth and survival of microorganisms. Acidophilic bioleaching bacteria are industrially applied for releasing metals from mineral sulphides, and they are considered extremely tolerant to oxidative conditions prevailing in acidic bioleaching environments. Such processes usually are performed in heaps and thus these microorganisms are also exposed to intermittent desiccations or high osmolarity periods that reduce the water availability. However, the tolerance to water stress and the molecular basis of adaptation to it are still largely unknown. The aim of this work was to determine the cellular response to desiccation stress and establish its relationship to oxidative stress response in the acidophilic iron-oxidizing bacteria Acidithiobacillus ferrooxidans ATCC 23270 and Leptospirillum ferriphilum DSM 14647. Results showed that the exposure of cell cultures to desiccation (0-120 min) led to a significant reduction in cell growth, and to an increase in content in reactive oxygen species in both bacteria. However, Leptospirillum ferriphilum turned out to be more tolerant than Acidithiobacillus ferrooxidans. In addition, the pre-treatment of the cell cultures with compatible solutes (trehalose and ectoine), and antioxidants (glutathione and cobalamin) restored all stress parameters to levels exhibited by the control cultures. To evaluate the role of the osmotic and redox homeostasis mechanisms in coping with desiccation stress, the relative expression of a set of selected genes was approached by RT-qPCR experiments in cells exposed to desiccation for 30 min. Results showed a generalized upregulation of genes that code for mechanosensitive channels, and enzymes related to the biosynthesis of compatible solutes and oxidative stress response in both bacteria. These data suggest that acidophiles show variable tolerance to desiccation and allow to establish that water stress can trigger oxidative stress, and thus anti-oxidative protection capability can be a relevant mechanism when cells are challenged by desiccation or other anhydrobiosis states.
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Affiliation(s)
- Muñoz-Villagrán Claudia
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile
| | - Acevedo-Arbunic Javiera
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile
| | - Navarro-Salazar Sebastián
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile
| | - Fuentes-Rubio José
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile
| | - Levicán Gloria
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile.
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Tobin LA, Jarocki VM, Kenyon J, Drigo B, Donner E, Djordjevic SP, Hamidian M. Genomic analysis of diverse environmental Acinetobacter isolates identifies plasmids, antibiotic resistance genes, and capsular polysaccharides shared with clinical strains. Appl Environ Microbiol 2024; 90:e0165423. [PMID: 38206028 PMCID: PMC10885009 DOI: 10.1128/aem.01654-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 11/30/2023] [Indexed: 01/12/2024] Open
Abstract
Acinetobacter baumannii, an important pathogen known for its widespread antibiotic resistance, has been the focus of extensive research within its genus, primarily involving clinical isolates. Consequently, data on environmental A. baumannii and other Acinetobacter species remain limited. Here, we utilized Illumina and Nanopore sequencing to analyze the genomes of 10 Acinetobacter isolates representing 6 different species sourced from aquatic environments in South Australia. All 10 isolates were phylogenetically distinct compared to clinical and other non-clinical Acinetobacter strains, often tens of thousands of single-nucleotide polymorphisms from their nearest neighbors. Despite the genetic divergence, we identified pdif modules (sections of mobilized DNA) carrying clinically important antimicrobial resistance genes in species other than A. baumannii, including carbapenemase oxa58, tetracycline resistance gene tet(39), and macrolide resistance genes msr(E)-mph(E). These pdif modules were located on plasmids with high sequence identity to those circulating in globally distributed A. baumannii ST1 and ST2 clones. The environmental A. baumannii isolate characterized here (SAAb472; ST350) did not possess any native plasmids; however, it could capture two clinically important plasmids (pRAY and pACICU2) with high transfer frequencies. Furthermore, A. baumannii SAAb472 possessed virulence genes and a capsular polysaccharide type analogous to clinical strains. Our findings highlight the potential for environmental Acinetobacter species to acquire and disseminate clinically important antimicrobial resistance genes, underscoring the need for further research into the ecology and evolution of this important genus.IMPORTANCEAntimicrobial resistance (AMR) is a global threat to human, animal, and environmental health. Studying AMR in environmental bacteria is crucial to understand the emergence and dissemination of resistance genes and pathogens, and to identify potential reservoirs and transmission routes. This study provides novel insights into the genomic diversity and AMR potential of environmental Acinetobacter species. By comparing the genomes of aquatic Acinetobacter isolates with clinical and non-clinical strains, we revealed that they are highly divergent yet carry pdif modules that encode resistance to antibiotics commonly used in clinical settings. We also demonstrated that an environmental A. baumannii isolate can acquire clinically relevant plasmids and carries virulence factors similar to those of hospital-associated strains. These findings suggest that environmental Acinetobacter species may serve as reservoirs and vectors of clinically important genes. Consequently, further research is warranted to comprehensively understand the ecology and evolution of this genus.
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Affiliation(s)
- Liam A. Tobin
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Veronica M. Jarocki
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, New South Wales, Australia
- The Australian Centre for Genomic Epidemiological Microbiology, University of Technology Sydney, Ultimo, Australia
| | - Johanna Kenyon
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Barbara Drigo
- Future Industries Institute, University of South Australia, Mawson Lakes, SA, Australia
- UniSA STEM, University of South Australia, Mawson Lakes, SA, Australia
| | - Erica Donner
- Future Industries Institute, University of South Australia, Mawson Lakes, SA, Australia
- Cooperative Research Centre for Solving Antimicrobial Resistance in Agribusiness, Food, and Environments (CRC SAAFE), Adelaide, SA, Australia
| | - Steven P. Djordjevic
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, New South Wales, Australia
- The Australian Centre for Genomic Epidemiological Microbiology, University of Technology Sydney, Ultimo, Australia
| | - Mehrad Hamidian
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, New South Wales, Australia
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Mendes SG, Combo SI, Allain T, Domingues S, Buret AG, Da Silva GJ. Co-regulation of biofilm formation and antimicrobial resistance in Acinetobacter baumannii: from mechanisms to therapeutic strategies. Eur J Clin Microbiol Infect Dis 2023; 42:1405-1423. [PMID: 37897520 PMCID: PMC10651561 DOI: 10.1007/s10096-023-04677-8] [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: 08/23/2023] [Accepted: 10/02/2023] [Indexed: 10/30/2023]
Abstract
In recent years, multidrug-resistant Acinetobacter baumannii has emerged globally as a major threat to the healthcare system. It is now listed by the World Health Organization as a priority one for the need of new therapeutic agents. A. baumannii has the capacity to develop robust biofilms on biotic and abiotic surfaces. Biofilm development allows these bacteria to resist various environmental stressors, including antibiotics and lack of nutrients or water, which in turn allows the persistence of A. baumannii in the hospital environment and further outbreaks. Investigation into therapeutic alternatives that will act on both biofilm formation and antimicrobial resistance (AMR) is sorely needed. The aim of the present review is to critically discuss the various mechanisms by which AMR and biofilm formation may be co-regulated in A. baumannii in an attempt to shed light on paths towards novel therapeutic opportunities. After discussing the clinical importance of A. baumannii, this critical review highlights biofilm-formation genes that may be associated with the co-regulation of AMR. Particularly worthy of consideration are genes regulating the quorum sensing system AbaI/AbaR, AbOmpA (OmpA protein), Bap (biofilm-associated protein), the two-component regulatory system BfmRS, the PER-1 β-lactamase, EpsA, and PTK. Finally, this review discusses ongoing experimental therapeutic strategies to fight A. baumannii infections, namely vaccine development, quorum sensing interference, nanoparticles, metal ions, natural products, antimicrobial peptides, and phage therapy. A better understanding of the mechanisms that co-regulate biofilm formation and AMR will help identify new therapeutic targets, as combined approaches may confer synergistic benefits for effective and safer treatments.
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Affiliation(s)
- Sérgio G Mendes
- Departments of Biological Sciences, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada
- Faculty of Pharmacy, University of Coimbra, 3000-548, Coimbra, Portugal
- Centre for Neuroscience and Cell Biology, University of Coimbra, 3000-548, Coimbra, Portugal
| | - Sofia I Combo
- Departments of Biological Sciences, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada
- Faculty of Pharmacy, University of Coimbra, 3000-548, Coimbra, Portugal
- Centre for Neuroscience and Cell Biology, University of Coimbra, 3000-548, Coimbra, Portugal
| | - Thibault Allain
- Departments of Biological Sciences, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada
| | - Sara Domingues
- Faculty of Pharmacy, University of Coimbra, 3000-548, Coimbra, Portugal
- Centre for Neuroscience and Cell Biology, University of Coimbra, 3000-548, Coimbra, Portugal
| | - Andre G Buret
- Departments of Biological Sciences, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada
| | - Gabriela J Da Silva
- Departments of Biological Sciences, Inflammation Research Network, University of Calgary, 2500 University Dr. N.W, Calgary, T2N 1N4, Canada.
- Faculty of Pharmacy, University of Coimbra, 3000-548, Coimbra, Portugal.
- Centre for Neuroscience and Cell Biology, University of Coimbra, 3000-548, Coimbra, Portugal.
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9
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Pfefferle K, Averhoff B. Wax Ester and Triacylglycerol Production in Acinetobacter baumannii: Role in Osmostress Protection, Reactive Oxygen Species, and Antibiotic Sensitivity. ACS Infect Dis 2023; 9:2093-2104. [PMID: 37883671 DOI: 10.1021/acsinfecdis.3c00214] [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: 10/28/2023]
Abstract
Wax esters (WEs) are neutral lipids that are produced by many different bacteria as potential carbon and energy storage compounds. Comparatively little is known about the role of WE in pathogenic bacteria. The opportunistic pathogen Acinetobacter baumannii is a major cause of hospital-acquired infections worldwide. Salt and desiccation resistance foster A. baumannii infections such as urinary tract infections and allow for reinfection when bacteria are taken up from dry surfaces in the hospital environment. Here we report on WE and triacylglycerol (TAG) production in A. baumannii as a response to nitrogen limitation and high salt stress. Fatty acids and fatty alcohols with chain lengths of C16 and C18 were identified as the most prominent WE constituents. We identified the terminal key enzyme of WE biosynthesis, the bifunctional wax ester synthase/acylCoA:diacylglycerol acyltransferase (WS/DGAT) encoded by the wax/dgat gene, and demonstrated that transcription of wax/dgat and production of WS/DGAT are independent of the nitrogen concentration. A Δwax/dgat mutant was impaired in growth in the presence of high salt concentration and was more sensitive to imipenem and reactive oxygen species.
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Affiliation(s)
- Katharina Pfefferle
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, 60438 Frankfurt, Germany
| | - Beate Averhoff
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, 60438 Frankfurt, Germany
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10
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Lu P, Xue J, Chen X, Ji X. DnaK-Mediated Protein Deamidation: a Potential Mechanism for Virulence and Stress Adaptation in Cronobacter sakazakii. Appl Environ Microbiol 2023; 89:e0050523. [PMID: 37382536 PMCID: PMC10370310 DOI: 10.1128/aem.00505-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/13/2023] [Indexed: 06/30/2023] Open
Abstract
Cronobacter sakazakii is a Gram-negative bacterium that causes infections in individuals of all ages, with neonates being the most vulnerable group. The objective of this study was to explore the function of the dnaK gene in C. sakazakii and to elucidate the impact of alterations in the protein composition regulated by dnaK on virulence and stress adaptation. Our research demonstrates the critical role of the dnaK gene in various key virulence factors, including adhesion, invasion, and acid resistance in C. sakazakii. Through the use of proteomic analysis, we discovered that deletion of the dnaK gene in C. sakazakii leads to an upregulation of protein abundance and increased levels of deamidated posttranscriptional modifications, suggesting that DnaK may play a role in maintaining proper protein activity by reducing protein deamidation in bacteria. These findings indicate that DnaK-mediated protein deamidation may be a novel mechanism for virulence and stress adaptation in C. sakazakii. These findings suggest that targeting DnaK could be a promising strategy for developing drugs to treat C. sakazakii infections. IMPORTANCE Cronobacter sakazakii can cause disease in individuals of all ages, with infections in premature infants being particularly deadly and resulting in bacterial meningitis and sepsis with a high mortality rate. Our study demonstrates that dnaK in Cronobacter sakazakii plays a critical role in virulence, adhesion, invasion, and acid resistance. Using proteomic analysis to compare protein changes in response to dnaK knockout, we found that dnaK knockout significantly upregulates the abundance of some proteins but also results in the deamidation of many proteins. Our research has identified a connection between molecular chaperones and protein deamidation, which suggests a potential future drug development strategy of targeting DnaK as a drug target.
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Affiliation(s)
- Ping Lu
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Tianjin, China
- Nankai University Affiliated Eye Hospital, Nankai University, Tianjin, China
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Juan Xue
- Institute of Infection and Immunity, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Xi Chen
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Tianjin, China
- Nankai University Affiliated Eye Hospital, Nankai University, Tianjin, China
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Xuemeng Ji
- School of Medicine, Nankai University, Tianjin, China
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11
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Venkateswaran P, Vasudevan S, David H, Shaktivel A, Shanmugam K, Neelakantan P, Solomon AP. Revisiting ESKAPE Pathogens: virulence, resistance, and combating strategies focusing on quorum sensing. Front Cell Infect Microbiol 2023; 13:1159798. [PMID: 37457962 PMCID: PMC10339816 DOI: 10.3389/fcimb.2023.1159798] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/08/2023] [Indexed: 07/18/2023] Open
Abstract
The human-bacterial association is long-known and well-established in terms of both augmentations of human health and attenuation. However, the growing incidents of nosocomial infections caused by the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.) call for a much deeper understanding of these organisms. Adopting a holistic approach that includes the science of infection and the recent advancements in preventing and treating infections is imperative in designing novel intervention strategies against ESKAPE pathogens. In this regard, this review captures the ingenious strategies commissioned by these master players, which are teamed up against the defenses of the human team, that are equally, if not more, versatile and potent through an analogy. We have taken a basketball match as our analogy, dividing the human and bacterial species into two teams playing with the ball of health. Through this analogy, we make the concept of infectious biology more accessible.
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Affiliation(s)
- Parvathy Venkateswaran
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Helma David
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Adityan Shaktivel
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Karthik Shanmugam
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Prasanna Neelakantan
- Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
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12
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Cavallo I, Oliva A, Pages R, Sivori F, Truglio M, Fabrizio G, Pasqua M, Pimpinelli F, Di Domenico EG. Acinetobacter baumannii in the critically ill: complex infections get complicated. Front Microbiol 2023; 14:1196774. [PMID: 37425994 PMCID: PMC10325864 DOI: 10.3389/fmicb.2023.1196774] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/05/2023] [Indexed: 07/11/2023] Open
Abstract
Acinetobacter baumannii is increasingly associated with various epidemics, representing a serious concern due to the broad level of antimicrobial resistance and clinical manifestations. During the last decades, A. baumannii has emerged as a major pathogen in vulnerable and critically ill patients. Bacteremia, pneumonia, urinary tract, and skin and soft tissue infections are the most common presentations of A. baumannii, with attributable mortality rates approaching 35%. Carbapenems have been considered the first choice to treat A. baumannii infections. However, due to the widespread prevalence of carbapenem-resistant A. baumannii (CRAB), colistin represents the main therapeutic option, while the role of the new siderophore cephalosporin cefiderocol still needs to be ascertained. Furthermore, high clinical failure rates have been reported for colistin monotherapy when used to treat CRAB infections. Thus, the most effective antibiotic combination remains disputed. In addition to its ability to develop antibiotic resistance, A. baumannii is also known to form biofilm on medical devices, including central venous catheters or endotracheal tubes. Thus, the worrisome spread of biofilm-producing strains in multidrug-resistant populations of A. baumannii poses a significant treatment challenge. This review provides an updated account of antimicrobial resistance patterns and biofilm-mediated tolerance in A. baumannii infections with a special focus on fragile and critically ill patients.
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Affiliation(s)
- Ilaria Cavallo
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Alessandra Oliva
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Rebecca Pages
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Francesca Sivori
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Mauro Truglio
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Giorgia Fabrizio
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Martina Pasqua
- Department of Biology and Biotechnology "C. Darwin" Sapienza University of Rome, Rome, Italy
| | - Fulvia Pimpinelli
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Enea Gino Di Domenico
- Department of Biology and Biotechnology "C. Darwin" Sapienza University of Rome, Rome, Italy
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13
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Roshini J, Patro LPP, Sundaresan S, Rathinavelan T. Structural diversity among Acinetobacter baumannii K-antigens and its implication in the in silico serotyping. Front Microbiol 2023; 14:1191542. [PMID: 37415807 PMCID: PMC10320297 DOI: 10.3389/fmicb.2023.1191542] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/30/2023] [Indexed: 07/08/2023] Open
Abstract
Acinetobacter baumannii is an emerging opportunistic pathogen. It exhibits multi-, extreme-, and pan-drug resistance against several classes of antibiotics. Capsular polysaccharide (CPS or K-antigen) is one of the major virulence factors which aids A. baumannii in evading the host immune system. K-antigens of A. baumannii exploit the Wzx/Wzy-dependent pathway that involves 13 different proteins for its assembly and transport onto the outer membrane. A total of 64 (out of 237 K-locus(KL) types) known K-antigen sugar repeating structures are discussed here and are classified into seven groups based on their initial sugars, QuiNAc4NAc, GalNAc, GlcNAc, Gal, QuiNAc/FucNAc, FucNAc, and GlcNAc along with Leg5Ac7Ac/Leg5Ac7R. Thus, the corresponding seven initializing glycosyltransferases (ItrA1, ItrA2, ItrA3, ItrA4, ItrB1, ItrB3, and ItrA3 along with ItrB2) exhibit serotype specificity. The modeled 3D-structural repository of the 64 K-antigens can be accessed at https://project.iith.ac.in/ABSD/k_antigen.html. The topology of K-antigens further reveals the presence of 2-6 and 0-4 sugar monomers in the main and side chains, respectively. The presence of negatively (predominant) or neutrally charged K-antigens is observed in A. baumannii. Such diversity in the K-antigen sugar composition provides the K-typing specificity (viz., 18-69% in terms of reliability) for Wza, Wzb, Wzc, Wzx, and Wzy proteins involved in the Wzx/Wzy-dependent pathway. Interestingly, the degree of uniqueness of these proteins among different K-types is estimated to be 76.79%, considering the 237 reference sequences. This article summarizes the A. baumannii K-antigen structural diversity and creation of a K-antigen digital repository and provides a systematic analysis of the K-antigen assembly and transportation marker proteins.
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14
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Wu HJ, Xiao ZG, Lv XJ, Huang HT, Liao C, Hui CY, Xu Y, Li HF. Drug‑resistant Acinetobacter baumannii: From molecular mechanisms to potential therapeutics (Review). Exp Ther Med 2023; 25:209. [PMID: 37090073 PMCID: PMC10119666 DOI: 10.3892/etm.2023.11908] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 02/24/2023] [Indexed: 04/25/2023] Open
Abstract
Bacterial drug resistance is increasingly becoming an important problem that needs to be solved urgently in modern clinical practices. Infection caused by Acinetobacter baumannii is a serious threat to the life and health of patients. The drug resistance rate of Acinetobacter baumannii strains is increasing, thus research on the drug resistance of Acinetobacter baumannii has also seen an increase. When patients are infected with drug-resistant Acinetobacter baumannii, the availability of suitable antibiotics commonly used in clinical practices is becoming increasingly limited and the prognosis of patients is worsening. Studying the molecular mechanism of the drug resistance of Acinetobacter baumannii is fundamental to solving the problem of drug-resistant Acinetobacter baumannii and potentially other 'super bacteria'. Drug resistance mechanisms primarily include enzymes, membrane proteins, efflux pumps and beneficial mutations. Research on the underlying mechanisms provides a theoretical basis for the use and development of antibiotics and the development of novel treatment methods.
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Affiliation(s)
- Hao-Jia Wu
- Clinical College of Traditional Chinese Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei 430065, P.R. China
| | - Zhi-Gang Xiao
- Department of Orthopedics, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei 430061, P.R. China
| | - Xiao-Juan Lv
- Department of Hepatology, Hubei Key Laboratory of The Theory and Application Research of Liver and Kidney in Traditional Chinese Medicine, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Hubei Province Academy of Traditional Chinese Medicine, Wuhan, Hubei 430074, P.R. China
| | - Hai-Tang Huang
- Department of Hepatology, Hubei Key Laboratory of The Theory and Application Research of Liver and Kidney in Traditional Chinese Medicine, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Hubei Province Academy of Traditional Chinese Medicine, Wuhan, Hubei 430074, P.R. China
| | - Chu Liao
- Department of Hepatology, Hubei Key Laboratory of The Theory and Application Research of Liver and Kidney in Traditional Chinese Medicine, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Hubei Province Academy of Traditional Chinese Medicine, Wuhan, Hubei 430074, P.R. China
| | - Chen-Yang Hui
- Department of Hepatology, Hubei Key Laboratory of The Theory and Application Research of Liver and Kidney in Traditional Chinese Medicine, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Hubei Province Academy of Traditional Chinese Medicine, Wuhan, Hubei 430074, P.R. China
| | - Yue Xu
- Clinical College of Traditional Chinese Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei 430065, P.R. China
| | - Heng-Fei Li
- Department of Hepatology, Hubei Key Laboratory of The Theory and Application Research of Liver and Kidney in Traditional Chinese Medicine, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, Hubei 430061, P.R. China
- Department of Infection, Hubei Province Academy of Traditional Chinese Medicine, Wuhan, Hubei 430074, P.R. China
- Correspondence to: Professor Heng-Fei Li, Department of Hepatology, Hubei Key Laboratory of The Theory and Application Research of Liver and Kidney in Traditional Chinese Medicine, Hubei Provincial Hospital of Traditional Chinese Medicine, Room 4, Garden Hill, Wuchang, Wuhan, Hubei 430061, P.R. China
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15
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Green KD, Thamban Chandrika N, Vu LY, Pang AH, Tsodikov OV, Garneau-Tsodikova S. Aromatic hydrazides: A potential solution for Acinetobacter baumannii infections. Eur J Med Chem 2023; 249:115165. [PMID: 36739749 PMCID: PMC9974912 DOI: 10.1016/j.ejmech.2023.115165] [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: 11/10/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/31/2023]
Abstract
The emergence of multidrug-resistant bacteria and the poor efficacy of available antibiotics against these infections have led to the urgent need for novel antibiotics. Acinetobacter baumannii is one of high-priority pathogens due to its ability to mount resistance to different classes of antibiotics. In an effort to provide novel agents in the fight against infections caused by A. baumannii, we synthesized a series of 46 aromatic hydrazides as potential treatments. In this series, 34 compounds were found to be low- to sub-μM inhibitors of A. baumannii growth, with MIC values in the range of 8 μg/mL to ≤0.125 μg/mL against a broad set of multidrug-resistant clinical isolates. These compounds were not highly active against other bacteria. We showed that one of the most potent compounds, 3e, was bacteriostatic and inhibitory to biofilm formation, although it did not disrupt the preformed biofilm. Additionally, we found that these compounds lacked mammalian cytotoxicity. The high antibacterial potency and the lack of mammalian cytotoxicity make these compounds a promising lead series for development of a novel selective anti-A. baumannii antibiotic.
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Affiliation(s)
- Keith D Green
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Nishad Thamban Chandrika
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Loan Y Vu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Allan H Pang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Oleg V Tsodikov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Sylvie Garneau-Tsodikova
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA.
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16
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McNeilly O, Mann R, Cummins ML, Djordjevic SP, Hamidian M, Gunawan C. Development of Nanoparticle Adaptation Phenomena in Acinetobacter baumannii: Physiological Change and Defense Response. Microbiol Spectr 2023; 11:e0285722. [PMID: 36625664 PMCID: PMC9927149 DOI: 10.1128/spectrum.02857-22] [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: 07/25/2022] [Accepted: 12/17/2022] [Indexed: 01/11/2023] Open
Abstract
The present work describes the evolution of a resistance phenotype to a multitargeting antimicrobial agent, namely, silver nanoparticles (nanosilver; NAg), in the globally prevalent bacterial pathogen Acinetobacter baumannii. The Gram-negative bacterium has recently been listed as a critical priority pathogen requiring novel treatment options by the World Health Organization. Through prolonged exposure to the important antimicrobial nanoparticle, the bacterium developed mutations in genes that encode the protein subunits of organelle structures that are involved in cell-to-surface attachment as well as in a cell envelope capsular polysaccharide synthesis-related gene. These mutations are potentially correlated with stable physiological changes in the biofilm growth behavior and with an evident protective effect against oxidative stress, most likely as a feature of toxicity defense. We further report a different adaptation response of A. baumannii to the cationic form of silver (Ag+). The bacterium developed a tolerance phenotype to Ag+, which was correlated with an indicative surge in respiratory activity and changes in cell morphology, of which these are reported characteristics of tolerant bacterial populations. The findings regarding adaptation phenomena to NAg highlight the risks of the long-term use of the nanoparticle on a priority pathogen. The findings urge the implementation of strategies to overcome bacterial NAg adaptation, to better elucidate the toxicity mechanisms of the nanoparticle, and preserve the efficacy of the potent alternative antimicrobial agent in this era of antimicrobial resistance. IMPORTANCE Several recent studies have reported on the development of bacterial resistance to broad-spectrum antimicrobial silver nanoparticles (nanosilver; NAg). NAg is currently one of the most important alternative antimicrobial agents. However, no studies have yet established whether Acinetobacter baumannii, a globally prevalent nosocomial pathogen, can develop resistance to the nanoparticle. The study herein describes how a model strain of A. baumannii with no inherent silver resistance determinants developed resistance to NAg, following prolonged exposure. The stable physiological changes are correlated with mutations detected in the bacterium genome. These mutations render the bacterium capable of proliferating at a toxic NAg concentration. It was also found that A. baumannii developed a "slower-to-kill" tolerance trait to Ag+, which highlights the unique antimicrobial activities between the nanoparticulate and the ionic forms of silver. Despite the proven efficacy of NAg, the observation of NAg resistance in A. baumannii emphasises the potential risks of the repeated overuse of this agent on a priority pathogen.
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Affiliation(s)
- Oliver McNeilly
- Australian Institute of Microbiology and Infection, University of Technology Sydney, Broadway, New South Wales, Australia
| | - Riti Mann
- Australian Institute of Microbiology and Infection, University of Technology Sydney, Broadway, New South Wales, Australia
| | - Max Laurence Cummins
- Australian Institute of Microbiology and Infection, University of Technology Sydney, Broadway, New South Wales, Australia
- Australian Centre for Genomic Epidemiological Microbiology, University of Technology Sydney, Broadway, New South Wales, Australia
| | - Steven P. Djordjevic
- Australian Institute of Microbiology and Infection, University of Technology Sydney, Broadway, New South Wales, Australia
- Australian Centre for Genomic Epidemiological Microbiology, University of Technology Sydney, Broadway, New South Wales, Australia
| | - Mehrad Hamidian
- Australian Institute of Microbiology and Infection, University of Technology Sydney, Broadway, New South Wales, Australia
| | - Cindy Gunawan
- Australian Institute of Microbiology and Infection, University of Technology Sydney, Broadway, New South Wales, Australia
- School of Chemical Engineering, University of New South Wales, Sydney, New South Wales, Australia
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17
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Lee YL, Ko WC, Hsueh PR. Geographic patterns of Acinetobacter baumannii and carbapenem resistance in the Asia-Pacific Region: results from the Antimicrobial Testing Leadership and Surveillance (ATLAS) program, 2012-2019. Int J Infect Dis 2023; 127:48-55. [PMID: 36516915 DOI: 10.1016/j.ijid.2022.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/12/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVES This study aimed to investigate the geographic distribution of carbapenem-resistant Acinetobacter baumannii (CR-AB) isolates in the Asia-Pacific region. METHODS We collected A. baumannii isolates using the Antimicrobial Testing Leadership and Surveillance program from 2012 to 2019. The minimum inhibitory concentrations (MICs) of the isolates were determined using the broth microdilution method. The major carbapenemase genes were identified using multiplex polymerase chain reaction assays for the isolates collected between 2012 and 2014. CR-AB was defined as isolates with meropenem MICs ≥8 mg/l. RESULTS In total, 2674 A. baumannii isolates were collected from 13 countries, of which 1918 (71.7%) were CR-AB. The carbapenem resistance rates among A. baumannii isolates were as low as 2.8% and 6.5% in Japan and Australia, respectively, but as high as 88% and 87.2% in South Korea and India, respectively. Of the 232 CR-AB isolates that underwent carbapenemase gene screening, 224 (96.6%) harbored at least one carbapenemase gene. A total of 226 carbapenemase genes were detected, with blaOXA-23 (94.7%, 214/226) being the most dominant, followed by blaOXA-72 (2.7%, 6/226), blaOXA-58 (2.2%, 5/226), and blaNDM-1 (0.4%, 1/226). CR-AB isolates had >80% resistance to amikacin, ampicillin/sulbactam, cefepime, ceftazidime, ciprofloxacin, levofloxacin, and piperacillin/tazobactam. The rates of CR-AB resistance to minocycline and colistin were 7.2% (31/429) and 1.7% (23/1368). For cefoperazone/sulbactam and tigecycline, 50.2% (527/1049) and 93.3% (1789/1918) of CR-AB isolates had an MIC ≤16 mg/l and ≤2 mg/l, respectively. CONCLUSION The prevalence of carbapenem resistance in A. baumannii showed significant differences among countries in the Asia-Pacific region, and the treatment options were limited.
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Affiliation(s)
- Yu-Lin Lee
- Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan; Institute of Genomics and Bioinformatics, National Chung-Hsing University, Taichung City, Taiwan
| | - Wen-Chien Ko
- Department of Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Po-Ren Hsueh
- Departments of Laboratory Medicine and Internal Medicine, China Medical University Hospital, Taichung, Taiwan; School of Medicine, China Medical University, Taichung, Taiwan; Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
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Pourhajibagher M, Hosseini N, Bahador A. Antimicrobial activity of D-amino acid in combination with photo-sonoactivated hypericin nanoparticles against Acinetobacter baumannii. BMC Microbiol 2023; 23:23. [PMID: 36658487 PMCID: PMC9850556 DOI: 10.1186/s12866-023-02758-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/06/2023] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND The emergence of multidrug-resistant Acinetobacter baumannii strains is increasing worldwide. To overcome these life-threatening infections, the development of new treatment approaches is critical. For this purpose, this study was conducted to determine the antimicrobial photo-sonodynamic therapy (aPSDT) using hypericin nanoparticles (HypNP) in combination with D-Tryptophan (D-Trp) against A. baumannii. MATERIALS AND METHODS HypNP was synthesized and characterized, followed by the determination of the fractional inhibitory concentration (FIC) index of HypNP and D-Trp by checkerboard assay. Next, the antimicrobial and anti-biofilm potential of HypNP@D-Trp-mediated aPSDT against A. baumannii was evaluated. Finally, the anti-virulence activity of aPSDT using HypNP@D-Trp was accessed following the characterization of HypNP@D-Trp interaction with AbaI using in silico virtual screening and molecular docking. RESULTS A synergistic activity in the combination of HypNP and D-Trp against A. baumannii was observed with a FIC index value of 0.5. There was a 5.10 log10 CFU/mL reduction in the cell viability of A. baumannii when the bacterial cells were treated with 1/2 × MIC of HypNP@D-Trp and subsequently exposed to ultrasound waves and blue light (P < 0.05). Moreover, a significant biofilm degradation effect on biofilm-associated cells of A. baumannii was observed after treatment with aPSDT using 2 × MIC of HypNP@D-Trp in comparison with the control groups (P < 0.05). According to the molecular docking analysis of the protein-ligand complex, Hyp with a high affinity for AbaI showed a binding affinity of - 9.41 kcal/mol. Also, the expression level of abaI gene was significantly downregulated by 10.32-fold in A. baumannii treated with aPSDT as comprised with the control group (P < 0.05). CONCLUSIONS It can be concluded that HypNP@D-Trp-mediated aPSDT can be considered a promising strategy to overcome the infections caused by A. baumannii by reducing the growth of bacterial biofilm and decreasing the expression of abaI as a gene involved in A. baumannii biofilm formation.
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Affiliation(s)
- Maryam Pourhajibagher
- grid.411705.60000 0001 0166 0922Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Nava Hosseini
- grid.23856.3a0000 0004 1936 8390Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, Université Laval, Quebec City, QC G1V 0A6 Canada ,grid.23856.3a0000 0004 1936 8390Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et de Génie, Université Laval, Quebec City, QC G1V 0A6 Canada ,grid.421142.00000 0000 8521 1798Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Quebec City, QC G1V 4G5 Canada
| | - Abbas Bahador
- Fellowship in Clinical Laboratory Sciences, BioHealth Lab, Tehran, Iran ,grid.411705.60000 0001 0166 0922Department of Microbiology, Tehran University of Medical Sciences, Tehran, Iran
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Ghadiri A, Doosti A, Shakhsi-Niaei M. Prevalence, Antimicrobial Susceptibility, and Distribution of Virulence Genes Involved in Biofilm Formation in Multidrug-Resistant Acinetobacter baumannii Isolated from Shahrekord Medical Centers, Chaharmahal and Bakhtiari, Iran. IRANIAN JOURNAL OF MEDICAL MICROBIOLOGY 2023. [DOI: 10.30699/ijmm.17.1.73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
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20
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Nithichanon A, Kewcharoenwong C, Da-oh H, Surajinda S, Khongmee A, Koosakunwat S, Wren BW, Stabler RA, Brown JS, Lertmemongkolchai G. Acinetobacter nosocomialis Causes as Severe Disease as Acinetobacter baumannii in Northeast Thailand: Underestimated Role of A. nosocomialis in Infection. Microbiol Spectr 2022; 10:e0283622. [PMID: 36227120 PMCID: PMC9769887 DOI: 10.1128/spectrum.02836-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/21/2022] [Indexed: 01/09/2023] Open
Abstract
Infections by Acinetobacter species are recognized as a serious global threat due to causing severe disease and their high levels of antibiotic resistance. Acinetobacter baumannii is the most prevalent pathogen in the genus, but infection by Acinetobacter nosocomialis has been reported widely. Diagnosis of patients with A. baumannii infection is often misdiagnosed with other Acinetobacter species, especially A. nosocomialis. This study investigated whether there were significant differences in clinical outcomes between patients infected with A. baumannii versus A. nosocomialis in Northeast Thailand, and to characterize serological responses to infection with these pathogens. The results show that A. baumannii had higher levels of multidrug resistance. Despite this, clinical outcomes for infection with A. baumannii or A. nosocomialis were similar with mortalities of 33% and 36%, respectively. Both pathogens caused community-acquired infections (A. baumannii 35% and A. nosocomialis 29% of cases). Plasma from uninfected healthy controls contained IgG antibody that recognized both organisms, and infected patients did not show a significantly enhanced antibody response from the first week versus 2 weeks later. Finally, the patterns of antigen recognition for plasma IgG were similar for patients infected with A. baumannii or A. nosocomialis infection, and distinct to the pattern for patients infected with non-Acinetobacter. In conclusion, our data revealed that infection with A. nosocomialis was associated with a similarly high level of mortality as infection with A. baumannii, the high rate of community-acquired infection and antibodies in uninfected individuals suggesting that there is significant community exposure to both pathogens. IMPORTANCE Bacterial infections by Acinetobacter species are global threats due to their severity and high levels of antibiotic resistance. A. baumannii is the most common pathogen in the genus; however, infection by A. nosocomialis has also been widely reported but is thought to be less severe. In this study, we have prospectively investigated 48 reported cases of A. baumannii infection in Northeast Thailand, and characterized the serological responses to infection. We found that 14 (29%) of these infections were actually caused by A. nosocomialis. Furthermore, the incidence of antibiotic resistance among A. nosocomialis strains, APACHE II scores, and mortality for patients infected with A. nosocomialis were much higher than published data. Both A. baumannii and A. nosocomialis had unexpectedly mortality rates of over 30%, and both pathogens caused a high rate of community-acquired infections. Importantly, background antibodies in uninfected individuals suggest significant community exposure to both pathogens in the environment.
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Affiliation(s)
- Arnone Nithichanon
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Research and Diagnostic Center for Emerging Infectious Diseases (RCEID), Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Chidchamai Kewcharoenwong
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Hudadini Da-oh
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Sirithorn Surajinda
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Aranya Khongmee
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | | | - Brendan W. Wren
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Infectious and Tropical Disease, London, United Kingdom
| | - Richard A. Stabler
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Infectious and Tropical Disease, London, United Kingdom
| | - Jeremy S. Brown
- Centre for Inflammation and Tissue Repair, UCL Respiratory, London, United Kingdom
| | - Ganjana Lertmemongkolchai
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
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Bai B, Eales BM, Huang W, Ledesma KR, Merlau PR, Li G, Yu Z, Tam VH. Clinical and genomic analysis of virulence-related genes in bloodstream infections caused by Acinetobacter baumannii. Virulence 2022; 13:1920-1927. [PMID: 36308002 PMCID: PMC9621070 DOI: 10.1080/21505594.2022.2132053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Acinetobacter baumannii has emerged as a common cause of bloodstream infections, which is associated with high mortality and long periods of hospitalization. To advance the medical care of our patients, the study was designed to identify microbial characteristics associated with poor clinical outcomes. A collection of 32 A. baumannii bloodstream isolates with diverse genetic backgrounds (as determined by multilocus sequence typing) was studied. These isolates were recovered by unique patients (18 males, 14 females; age range: 17 days to 87 years) between 2011 and 2018. A sequential screening approach (cross-referencing analyses using different endpoints) was used to identify isolates with the best correlation between bacterial virulence and clinical prognosis. Isolates associated with more rapid in vitro growth rate, shorter median survival time in pre-clinical infection models, and hospital mortality were selected as candidates for high virulence, while those with opposite characteristics were selected as controls with low virulence. Whole genome sequencing was undertaken in the most promising clinical isolates. We found five virulence genes (beta-hemolysin/cytolysin, Cpi-1a + Cpi-1 (SPI-1 like), enhanced entry proteins, FbpABC, Paa) and 1 secretory system (T6SS) only present in a highly virulent isolate (AB23), compared to a low virulence control isolate (AB6). These genetic elements could be associated with the poor prognosis of A. baumannii bacteraemia and further investigations are warranted.
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Affiliation(s)
- Bing Bai
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, Shenzhen, Guangdong, China,Department of Pharmacy Practice and Translational Research, University of Houston, Houston, Texas, USA
| | - Brianna M. Eales
- Department of Pharmacy Practice and Translational Research, University of Houston, Houston, Texas, USA
| | - Wei Huang
- Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen Institute of Respiratory Diseases, Shenzhen People’s Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, China
| | - Kimberly R. Ledesma
- Department of Pharmacy Practice and Translational Research, University of Houston, Houston, Texas, USA
| | - Paul R. Merlau
- Department of Pharmacy Practice and Translational Research, University of Houston, Houston, Texas, USA
| | - Guiqiu Li
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, Shenzhen, Guangdong, China
| | - Zhijian Yu
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6th Affiliated Hospital of Shenzhen University Health Center, Shenzhen, Guangdong, China,Department of Pharmacy Practice and Translational Research, University of Houston, Houston, Texas, USA
| | - Vincent H. Tam
- Department of Pharmacy Practice and Translational Research, University of Houston, Houston, Texas, USA,CONTACT Vincent H. Tam
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Tomlinson BR, Denham GA, Torres NJ, Brzozowski RS, Allen JL, Jackson JK, Eswara PJ, Shaw LN. Assessing the Role of Cold-Shock Protein C: a Novel Regulator of Acinetobacter baumannii Biofilm Formation and Virulence. Infect Immun 2022; 90:e0037622. [PMID: 36121221 PMCID: PMC9584223 DOI: 10.1128/iai.00376-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 08/30/2022] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii is a formidable opportunistic pathogen that is notoriously difficult to eradicate from hospital settings. This resilience is often attributed to a proclivity for biofilm formation, which facilitates a higher tolerance toward external stress, desiccation, and antimicrobials. Despite this, little is known regarding the mechanisms orchestrating A. baumannii biofilm formation. Here, we performed RNA sequencing (RNA-seq) on biofilm and planktonic populations for the multidrug-resistant isolate AB5075 and identified 438 genes with altered expression. To assess the potential role of genes upregulated within biofilms, we tested the biofilm-forming capacity of their respective mutants from an A. baumannii transposon library. In so doing, we uncovered 24 genes whose disruption led to reduced biofilm formation. One such element, cold shock protein C (cspC), had a highly mucoid colony phenotype, enhanced tolerance to polysaccharide degradation, altered antibiotic tolerance, and diminished adherence to abiotic surfaces. RNA-seq of the cspC mutant revealed 201 genes with altered expression, including the downregulation of pili and fimbria genes and the upregulation of multidrug efflux pumps. Using transcriptional arrest assays, it appears that CspC mediates its effects, at least in part, through RNA chaperone activity, influencing the half-life of several important transcripts. Finally, we show that CspC is required for survival during challenge by the human immune system and is key for A. baumannii dissemination and/or colonization during systemic infection. Collectively, our work identifies a cadre of new biofilm-associated genes within A. baumannii and provides unique insight into the global regulatory network of this emerging human pathogen.
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Affiliation(s)
- Brooke R. Tomlinson
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Grant A. Denham
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Nathanial J. Torres
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Robert S. Brzozowski
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Jessie L. Allen
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Jessica K. Jackson
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Prahathees J. Eswara
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
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Hou S, Wu H, Chen S, Li X, Zhang Z, Cheng Y, Chen Y, He M, An Q, Man C, Du L, Chen Q, Wang F. Bovine skin fibroblasts mediated immune responses to defend against bovine Acinetobacter baumannii infection. Microb Pathog 2022; 173:105806. [PMID: 36179976 DOI: 10.1016/j.micpath.2022.105806] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 09/13/2022] [Accepted: 09/22/2022] [Indexed: 10/14/2022]
Abstract
Acinetobacter baumannii (A. baumannii) is an opportunistic pathogen which can cause pneumonia, sepsis and infections of skin and soft tissue. The host mostly relies on innate immune responses to defend against the infection of A. baumannii. Currently, it has been confirmed that fibroblasts involved in innate immune responses. Therefore, to explore how bovine skin fibroblasts mediated immune responses to defend against A. baumannii infection, we analyzed the differential transcripts data of bovine skin fibroblasts infected with bovine A. baumannii by RNA-sequencing (RNA-seq). We found that there were 3014 differentially expressed genes (DEGs) at 14h with bovine A. baumannii infection, including 1940 up-regulated genes and 1074 down-regulated genes. Gene Ontology (GO) enrichment showed that ubiquitin protein ligase binding, IL-6 receptor complex, ERK1 and ERK2 cascade terms were mainly enriched. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment showed that innate immune pathways were significantly enriched, such as TNF, IL-17, NLR, MAPK, NF-κB, endocytosis, apoptosis and HIF-1 signaling pathways. Furthermore, Gene Set Enrichment Analysis (GSEA) revealed that GO terms such as chemokine receptor binding and Th17 cell differentiation and KEGG pathways such as TLR and cytokine-cytokine receptor interaction pathways were up-regulated. In addition, CASP3 and JUN were the core functional genes of apoptosis, while IL-6, ERBB2, EGFR, CHUK and MAPK8 were the core functional genes of immunity by Protein-Protein Interaction (PPI) analysis. Our study provided an in-depth understanding of the molecular mechanisms of fibroblasts against A. baumannii infection. It also lays the foundation for the development of new therapeutic targets for the diseases caused by A. baumannii infection and formulates effective therapeutic strategies for the prevention and control of the diseases caused by A. baumannii.
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Affiliation(s)
- Simeng Hou
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Haotian Wu
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Si Chen
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Xubo Li
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Zhenxing Zhang
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Yiwen Cheng
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Yuanyuan Chen
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Meirong He
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Qi An
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Churiga Man
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Li Du
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Qiaoling Chen
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
| | - Fengyang Wang
- Hainan Key Lab of Tropical Animal Reproduction, Breeding and Epidemic Disease Research, Animal Genetic Engineering Key Lab of Haikou, College of Animal Science and Technology, Hainan University, Haikou, Hainan, China.
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Dolma KG, Khati R, Paul AK, Rahmatullah M, de Lourdes Pereira M, Wilairatana P, Khandelwal B, Gupta C, Gautam D, Gupta M, Goyal RK, Wiart C, Nissapatorn V. Virulence Characteristics and Emerging Therapies for Biofilm-Forming Acinetobacter baumannii: A Review. BIOLOGY 2022; 11:biology11091343. [PMID: 36138822 PMCID: PMC9495682 DOI: 10.3390/biology11091343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/04/2022] [Accepted: 09/08/2022] [Indexed: 11/20/2022]
Abstract
Simple Summary Acinetobacter baumannii (A. baumannii) is one of the ESKAPE organisms and has the competency to build biofilms. These biofilms account for the most nosocomial infections all over the world. This review reflects on the various physicochemical and environmental factors such as adhesion, pili expression, growth surfaces, drug-resistant genes, and virulence factors that profoundly affect its resistant forte. Emerging drug-resistant issues and limitations to newer drugs are other factors affecting the hospital environment. Here, we discuss newer and alternative methods that can significantly enhance the susceptibility to Acinetobacter spp. Many new antibiotics are under trials, such as GSK-3342830, The Cefiderocol (S-649266), Fimsbactin, and similar. On the other hand, we can also see the impact of traditional medicine and the secondary metabolites of these natural products’ application in searching for new treatments. The field of nanoparticles has demonstrated effective antimicrobial actions and has exhibited encouraging results in the field of nanomedicine. The use of various phages such as vWUPSU and phage ISTD as an alternative treatment for its specificity and effectiveness is being investigated. Cathelicidins obtained synthetically or from natural sources can effectively produce antimicrobial activity in the micromolar range. Radioimmunotherapy and photodynamic therapy have boundless prospects if explored as a therapeutic antimicrobial strategy. Abstract Acinetobacter species is one of the most prevailing nosocomial pathogens with a potent ability to develop antimicrobial resistance. It commonly causes infections where there is a prolonged utilization of medical devices such as CSF shunts, catheters, endotracheal tubes, and similar. There are several strains of Acinetobacter (A) species (spp), among which the majority are pathogenic to humans, but A. baumannii are entirely resistant to several clinically available antibiotics. The crucial mechanism that renders them a multidrug-resistant strain is their potent ability to synthesize biofilms. Biofilms provide ample opportunity for the microorganisms to withstand the harsh environment and further cause chronic infections. Several studies have enumerated multiple physiological and virulence factors responsible for the production and maintenance of biofilms. To further enhance our understanding of this pathogen, in this review, we discuss its taxonomy, pathogenesis, current treatment options, global resistance rates, mechanisms of its resistance against various groups of antimicrobials, and future therapeutics.
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Affiliation(s)
- Karma G. Dolma
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Rachana Khati
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Alok K. Paul
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7001, Australia
| | - Mohammed Rahmatullah
- Department of Biotechnology & Genetic Engineering, University of Development Alternative, Lalmatia, Dhaka 1207, Bangladesh
| | - Maria de Lourdes Pereira
- CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
- Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Correspondence: (P.W.); (V.N.)
| | - Bidita Khandelwal
- Department of Medicine, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Chamma Gupta
- Department of Biotechnology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Deepan Gautam
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Madhu Gupta
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Ramesh K. Goyal
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Christophe Wiart
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Veeranoot Nissapatorn
- School of Allied Health Sciences and World Union for Herbal Drug Discovery (WUHeDD), Walailak University, Nakhon Si Thammarat 80160, Thailand
- Correspondence: (P.W.); (V.N.)
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Gautam LK, Sharma P, Capalash N. Structural insight into substrate binding of Acinetobacter baumannii polyphosphate-AMP phosphotransferase (PPK2), a novel drug target. Biochem Biophys Res Commun 2022; 626:107-113. [PMID: 35987095 DOI: 10.1016/j.bbrc.2022.07.090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 07/23/2022] [Indexed: 11/02/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen known for high morbidity and mortality. It causes life-threatening infections, such as ventilator-associated pneumonia (VAP), bacteremia, meningitis, wound and urinary tract infections (UTI). Increase in carbapenem resistance exhibited by A. baumannii has accentuated the need for novel targets for effective treatment. Despite the pronounced relevance of PPK2 as a pathogenicity determinant in several pathogens, it has not been explored as a drug target in A. baumannii. The present study was piloted to investigate the substrate binding by A. baumannii PPK2 (AbPPK2), a two-domain Class II polyphosphate kinase 2. A homology model of AbPPK2 was developed and validated for molecular docking of ATP and ADP in the predicted binding pocket. Further analysis of AbPPK2 revealed a set of common residues in the catalytic cleft interacting with ATP and ADP which would be useful for the screening of inhibitors against A. baumannii.
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Affiliation(s)
- Lalit Kumar Gautam
- Department of Biotechnology, Panjab University, BMS Block-I, Sector- 25, Chandigarh, 160014, India.
| | - Prince Sharma
- Department of Microbiology, Panjab University, BMS Block-I, Sector- 25, Chandigarh, 160014, India.
| | - Neena Capalash
- Department of Biotechnology, Panjab University, BMS Block-I, Sector- 25, Chandigarh, 160014, India.
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Hussain EA, Qasim Hameed H, Mujahid Al-Shuwaikh A, Mujahid Abdullah R. Detection of the aadA1 and aac (3)-1V resistance genes in Acinetobacter baumannii. ARCHIVES OF RAZI INSTITUTE 2022; 77:959-966. [PMID: 36618317 PMCID: PMC9759248 DOI: 10.22092/ari.2022.357271.2010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 01/16/2022] [Indexed: 01/10/2023]
Abstract
Acinetobacter baumannii is a gram-negative aerobic bacterium that can be found in different environments, such as food, containing vegetables, meat, and fish; moreover, it can be present in soil and freshwater. A. baumannii has globally considered an opportunistic nosocomial bacterium in the healthcare setting contributing to increased morbidity and mortality. The current study aimed to detect the aminoglycoside genes in A. baumannii isolated from different clinical causes. In total, 20 isolates of A. baumannii were obtained from different clinical cases. Bacterial isolate DNA was extracted using a DNA extraction kit. Quantus Fluorometer was used to detect the concentration of the extracted DNA in order to detect the goodness of samples. 1 μl of DNA and 199 μl of diluted QuantiFlour Dye were mixed. After 5 min incubation at room temperature, DNA concentration values were evaluated, and following the initial amplification of the A. baumannii aadA1 gene, 20 μl of PCR product with F and R primers were sent to Sanger sequencing. The results of the antimicrobial susceptibility revealed that A. baumannii isolates were resistant to Gentamicin (95%), Amikacin (90%), and Tobramycin (60%). Molecular investigation of the aadA1 and aac (3)-IV genes exhibited that the aadA1 gene was detected in 15% of the isolates. However, the aac (3)-IV gene was not detected in any of the isolates. The gel electrophoresis revealed that the molecular weight of the aadA1 gene was 490bp. The DNA sequence of the aadA1 gene was conducted in this study, and the results exhibited no mutations in all isolates.
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Affiliation(s)
- E. A Hussain
- Department of Biology, College of Education for Pure Science Ibn-Al Haitham, University of Baghdad, Baghdad, Iraq
| | - H Qasim Hameed
- Department of Biology, College of Education for Pure Science Ibn-Al Haitham, University of Baghdad, Baghdad, Iraq
| | | | - R Mujahid Abdullah
- Department of Biology, College of Education for Pure Science Ibn-Al Haitham, University of Baghdad, Baghdad, Iraq
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27
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Wijers CDM, Pham L, Douglass MV, Skaar EP, Palmer LD, Noto MJ. Gram-negative bacteria act as a reservoir for aminoglycoside antibiotics that interact with host factors to enhance bacterial killing in a mouse model of pneumonia. FEMS MICROBES 2022; 3:xtac016. [PMID: 35909464 PMCID: PMC9326624 DOI: 10.1093/femsmc/xtac016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/04/2022] [Accepted: 05/11/2022] [Indexed: 01/28/2023] Open
Abstract
In vitro exposure of multiple Gram-negative bacteria to an aminoglycoside (AG) antibiotic has previously been demonstrated to result in bacterial alterations that interact with host factors to suppress Gram-negative pneumonia. However, the mechanisms resulting in suppression are not known. Here, the hypothesis that Gram-negative bacteria bind and retain AGs, which are introduced into the lung and interact with host defenses to affect bacterial killing, was tested. Following in vitro exposure of one of several, pathogenic Gram-negative bacteria to the AG antibiotics kanamycin or gentamicin, AGs were detected in bacterial cell pellets (up to 208 μg/mL). Using inhibitors of AG binding and internalization, the bacterial outer membrane was implicated as the predominant kanamycin and gentamicin reservoir. Following intranasal administration of gentamicin-bound bacteria or gentamicin solution at the time of infection with live, AG-naïve bacteria, gentamicin was detected in the lungs of infected mice (up to 8 μg/g). Co-inoculation with gentamicin-bound bacteria resulted in killing of AG-naïve bacteria by up to 3-log10, mirroring the effects of intranasal gentamicin treatment. In vitro killing of AG-naïve bacteria mediated by kanamycin-bound bacteria required the presence of detergents or pulmonary surfactant, suggesting that increased bacterial killing inside the murine lung is facilitated by the detergent component of pulmonary surfactant. These findings demonstrate that Gram-negative bacteria bind and retain AGs that can interact with host-derived pulmonary surfactant to enhance bacterial killing in the lung. This may help explain why AGs appear to have unique efficacy in the lung and might expand their clinical utility.
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Affiliation(s)
- Christiaan D M Wijers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt
University Medical Center, 1161 21st Avenue South, Nashville, TN 37232,
United States,Vanderbilt Institute for Infection, Immunology, and Inflammation,
Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville,
TN 37232, United States
| | - Ly Pham
- Department of Pathology, Microbiology, and Immunology, Vanderbilt
University Medical Center, 1161 21st Avenue South, Nashville, TN 37232,
United States,Vanderbilt Institute for Infection, Immunology, and Inflammation,
Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville,
TN 37232, United States
| | - Martin V Douglass
- Department of Pathology, Microbiology, and Immunology, Vanderbilt
University Medical Center, 1161 21st Avenue South, Nashville, TN 37232,
United States,Vanderbilt Institute for Infection, Immunology, and Inflammation,
Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville,
TN 37232, United States
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt
University Medical Center, 1161 21st Avenue South, Nashville, TN 37232,
United States,Vanderbilt Institute for Infection, Immunology, and Inflammation,
Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville,
TN 37232, United States
| | - Lauren D Palmer
- Department of Microbiology and Immunology, University of Illinois
Chicago, 835 South Wolcott Avenue, Chicago, IL 60612, United States
| | - Michael J Noto
- Corresponding author: Room 205H Whitehead Biomedical Research Building, Emory
University, 615 Michael Street, Atlanta, GA 30322, United States. Tel: (+404)712-2988;
E-mail:
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28
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Stapling of Peptides Potentiates: The Antibiotic Treatment of Acinetobacter baumannii In Vivo. Antibiotics (Basel) 2022; 11:antibiotics11020273. [PMID: 35203875 PMCID: PMC8868297 DOI: 10.3390/antibiotics11020273] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/15/2022] [Accepted: 02/18/2022] [Indexed: 11/21/2022] Open
Abstract
The rising incidence of multidrug resistance in Gram-negative bacteria underlines the urgency for novel treatment options. One promising new approach is the synergistic combination of antibiotics with antimicrobial peptides. However, the use of such peptides is not straightforward; they are often sensitive to proteolytic degradation, which greatly limits their clinical potential. One approach to increase stability is to apply a hydrocarbon staple to the antimicrobial peptide, thereby fixing them in an α-helical conformation, which renders them less exposed to proteolytic activity. In this work we applied several different hydrocarbon staples to two previously described peptides shown to act on the outer membrane, L6 and L8, and tested their activity in a zebrafish embryo infection model using a clinical isolate of Acinetobacter baumannii as a pathogen. We show that the introduction of such a hydrocarbon staple to the peptide L8 improves its in vivo potentiating activity on antibiotic treatment, without increasing its in vivo antimicrobial activity, toxicity or hemolytic activity.
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29
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Tobramycin Stress Induced Differential Gene Expression in Acinetobacter baumannii. Curr Microbiol 2022; 79:88. [PMID: 35129693 DOI: 10.1007/s00284-022-02788-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 01/24/2022] [Indexed: 11/03/2022]
Abstract
Acinetobacter baumannii is a multidrug-resistant bacteria responsible for nosocomial infections with significant fatality rates globally. Therapeutic failure and relapse of infection has been associated with persister cells formation which can also lead to resistance in A. baumannii. In the present study, we observed that A. baumannii ATCC 17978 in exponential phase survived lethal concentrations of amikacin, rifampicin and ciprofloxacin by generating persister cells but was unable to survive tobramycin treatment. The transcriptome of A. baumannii ATCC 17978 was analyzed following exposure to a high concentration of tobramycin (10 × MIC) for a short period of time to study the possible mechanisms responsible for lethality. Tobramycin reduced the expression of genes involved in energy production (nuoH, nuoN, nuoM, cydA, sucC), oxidative stress protection (tauD, cysD), and nutrition uptake (ompW) significantly. In addition, hemerythrin (non-heme di-iron oxygen-binding protein) was found to be the most downregulated gene in response to tobramycin which needs to be further studied for its role in susceptibility to antibiotics. Tobramycin upregulated the expression of genes that are mainly involved in stress response (leucine catabolism, DNA repair and HicAB toxin-antitoxin system). The differentially expressed genes highlighted in the study provided insight into the probable molecular mechanism of tobramycin-induced cell death and revealed some novel targets that can be explored further for their potential to control A. baumannii.
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30
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Magda M, Bettoni S, Laabei M, Fairley D, Russo TA, Riesbeck K, Blom AM. Clinical Isolates of Acinetobacter spp. Are Highly Serum Resistant Despite Efficient Recognition by the Complement System. Front Immunol 2022; 13:814193. [PMID: 35173727 PMCID: PMC8841485 DOI: 10.3389/fimmu.2022.814193] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/13/2022] [Indexed: 11/13/2022] Open
Abstract
Gram-negative bacteria from the genus Acinetobacter are responsible for life-threating hospital-related infections such as pneumonia, septicemia, and meningitis, especially in immunocompromised patients. Worryingly, Acinetobacter have become multi- and extensively drug resistant (MDR/XDR) over the last few decades. The complement system is the first line of defense against microbes, thus it is highly important to increase our understanding of evasion mechanisms used by Acinetobacter spp. Here, we studied clinical isolates of Acinetobacter spp. (n=50), aiming to characterize their recognition by the complement system. Most isolates tested survived 1 h incubation in 30% serum, and only 8 isolates had a lower survival rate, yet none of those isolates were fully killed. Intriguingly, four isolates survived in human whole blood containing all cell component. Their survival was, however, significantly reduced. Flow cytometry analyses revealed that most of the isolates were detected by human IgG and IgM. Interestingly, we could not detect any significant concentration of deposited C1q, despite observing C4b deposition that was abolished in C1q-deficient serum, indicating transient binding of C1q to bacteria. Moreover, several isolates were recognized by MBL, with C4b deposition abolished in MBL-deficient serum. C3b was deposited on most isolates, but this was not, however, seen with respect to C5b and formation of the membrane attack complex (MAC), indicating that many isolates could avoid complement-mediated lysis. India ink staining showed that isolates were capsulated, and capsule thickness varied significantly between isolates. Studies performed on a wild-type strain and capsule mutant strains, demonstrated that the production of a capsular polysaccharide is one mechanism that mediates resistance to complement-mediated bactericidal activity by preventing MAC deposition and lysis. Our data showed that most clinical Acinetobacter spp. isolates are highly serum resistant despite being efficiently recognized by the complement system.
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Affiliation(s)
- Michal Magda
- Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Serena Bettoni
- Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Maisem Laabei
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Derek Fairley
- Department of Microbiology, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Thomas A. Russo
- Veterans Administration Western New York Healthcare System, Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, University Buffalo, Buffalo, NY, United States
| | - Kristian Riesbeck
- Clinical Microbiology, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Anna M. Blom
- Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
- *Correspondence: Anna M. Blom,
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31
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OUP accepted manuscript. J Antimicrob Chemother 2022; 77:934-943. [DOI: 10.1093/jac/dkac010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 12/26/2021] [Indexed: 11/14/2022] Open
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32
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Kumar S, Anwer R, Azzi A. Virulence Potential and Treatment Options of Multidrug-Resistant (MDR) Acinetobacter baumannii. Microorganisms 2021; 9:microorganisms9102104. [PMID: 34683425 PMCID: PMC8541637 DOI: 10.3390/microorganisms9102104] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/18/2021] [Accepted: 09/21/2021] [Indexed: 12/12/2022] Open
Abstract
Acinetobacter baumannii is an opportunistic pathogen which is undoubtedly known for a high rate of morbidity and mortality in hospital-acquired infections. A. baumannii causes life-threatening infections, including; ventilator-associated pneumonia (VAP), meningitis, bacteremia, and wound and urinary tract infections (UTI). In 2017, the World Health Organization listed A. baumannii as a priority-1 pathogen. The prevalence of A. baumannii infections and outbreaks emphasizes the direct need for the use of effective therapeutic agents for treating such infections. Available antimicrobials, such as; carbapenems, tigecycline, and colistins have insufficient effectiveness due to the appearance of multidrug-resistant strains, accentuating the need for alternative and novel therapeutic remedies. To understand and overcome this menace, the knowledge of recent discoveries on the virulence factors of A. baumannii is needed. Herein, we summarized the role of various virulence factors, including; outer membrane proteins, efflux pumps, biofilm, penicillin-binding proteins, and siderophores/iron acquisition systems. We reviewed the recent scientific literature on different A. baumannii virulence factors and the effective antimicrobial agents for the treatment and management of bacterial infections.
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Affiliation(s)
- Sunil Kumar
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to Be University), Mullana, Ambala 133207, India;
| | - Razique Anwer
- Department of Pathology, College of Medicine, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 13317-4233, Saudi Arabia;
| | - Arezki Azzi
- Department of Biochemistry, College of Medicine, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 13317-4233, Saudi Arabia
- Correspondence:
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33
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Milani ES, Hasani A, Varschochi M, Sadeghi J, Memar MY, Hasani A. Biocide resistance in Acinetobacter baumannii: appraising the mechanisms. J Hosp Infect 2021; 117:135-146. [PMID: 34560167 DOI: 10.1016/j.jhin.2021.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 11/17/2022]
Abstract
A global upsurge in antibiotic-resistant Acinetobacter baumannii requires supervised selection of biocides and disinfectants to avert nosocomial infections by reducing its spread. Moreover, inadequate and improper biocides have been reported as a contributing factor in antimicrobial resistance. Regardless of the manner of administration, a biocidal concentration that does not kill the target bacteria creates a stress response, propagating the resistance mechanisms. This is an essential aspect of the disinfection programme and the overall bio-contamination management plan. Knowing the mechanisms of action of biocides and resistance modalities may open new avenues to discover novel agents. This review describes the mechanisms of action of some biocides, resistance mechanisms, and approaches to study susceptibility/resistance to these agents.
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Affiliation(s)
- E S Milani
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - A Hasani
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Clinical Research Development Unit, Sina Educational, Research and Treatment Centre, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - M Varschochi
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
| | - J Sadeghi
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - M Y Memar
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
| | - A Hasani
- Department of Clinical Biochemistry and Laboratory Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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34
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Crippen CS, Glushka J, Vinogradov E, Szymanski CM. Trehalose-deficient Acinetobacter baumannii exhibits reduced virulence by losing capsular polysaccharide and altering membrane integrity. Glycobiology 2021; 31:1520-1530. [PMID: 34473830 DOI: 10.1093/glycob/cwab096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/14/2021] [Accepted: 08/15/2021] [Indexed: 12/20/2022] Open
Abstract
A. baumannii has become the leading cause of bacterial nosocomial infections in part due to its ability to resist desiccation, disinfection and antibiotics. Several factors contribute to the tenacity and virulence of this pathogen, including production of a broad range of surface glycoconjugates, secretory systems and efflux pumps. We became interested in examining the importance of trehalose in A. baumannii after comparing intact bacterial cells by high resolution magic angle spinning NMR and noting high levels of this disaccharide obscuring all other resonances in the spectrum. Since this was observed under normal growth conditions, we speculated that trehalose must serve additional functions beyond osmolyte homeostasis. Using the virulent isolate A. baumannii AB5075 and mutants in the trehalose synthesis pathway, ∆otsA and ∆otsB, we found that the trehalose-deficient ∆otsA showed increased sensitivity to desiccation, colistin, serum complement and peripheral blood mononuclear cells while trehalose-6-phosphate producing ∆otsB behaved similar to the wildtype. The ∆otsA mutant also demonstrated increased membrane permeability and loss of capsular polysaccharide. These findings demonstrate that trehalose deficiency leads to loss of virulence in A. baumannii AB5075.
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Affiliation(s)
- Clay S Crippen
- Department of Microbiology, University of Georgia, Athens, GA, USA.,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - John Glushka
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Evgeny Vinogradov
- Human Health Therapeutics, National Research Council, Ottawa, ON, Canada
| | - Christine M Szymanski
- Department of Microbiology, University of Georgia, Athens, GA, USA.,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
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35
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Crippen CS, Zhou B, Andresen S, Patry RT, Muszyński A, Parker CT, Cooper KK, Szymanski CM. RNA and Sugars, Unique Properties of Bacteriophages Infecting Multidrug Resistant Acinetobacter radioresistens Strain LH6. Viruses 2021; 13:1652. [PMID: 34452516 PMCID: PMC8402811 DOI: 10.3390/v13081652] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/14/2021] [Accepted: 08/16/2021] [Indexed: 11/17/2022] Open
Abstract
Bacteriophages (phages) are predicted to be the most ubiquitous biological entity on earth, and yet, there are still vast knowledge gaps in our understanding of phage diversity and phage-host interactions. Approximately one hundred Acinetobacter-infecting DNA viruses have been identified, and in this report, we describe eight more. We isolated two typical dsDNA lytic podoviruses (CAP1-2), five unique dsRNA lytic cystoviruses (CAP3-7), and one dsDNA lysogenic siphovirus (SLAP1), all capable of infecting the multidrug resistant isolate Acinetobacter radioresistens LH6. Using transmission electron microscopy, bacterial mutagenesis, phage infectivity assays, carbohydrate staining, mass-spectrometry, genomic sequencing, and comparative studies, we further characterized these phages. Mutation of the LH6 initiating glycosyltransferase homolog, PglC, necessary for both O-linked glycoprotein and capsular polysaccharide (CPS) biosynthesis, prevented infection by the lytic podovirus CAP1, while mutation of the pilin protein, PilA, prevented infection by CAP3, representing the lytic cystoviruses. Genome sequencing of the three dsRNA segments of the isolated cystoviruses revealed low levels of homology, but conserved synteny with the only other reported cystoviruses that infect Pseudomonas species. In Pseudomonas, the cystoviruses are known to be enveloped phages surrounding their capsids with the inner membrane from the infected host. To characterize any membrane-associated glycoconjugates in the CAP3 cystovirus, carbohydrate staining was used to identify a low molecular weight lipid-linked glycoconjugate subsequently identified by mutagenesis and mass-spectrometry as bacterial lipooligosaccharide. Together, this study demonstrates the isolation of new Acinetobacter-infecting phages and the determination of their cell receptors. Further, we describe the genomes of a new genus of Cystoviruses and perform an initial characterization of membrane-associated glycoconjugates.
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Affiliation(s)
- Clay S. Crippen
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (C.S.C.); (B.Z.); (S.A.); (R.T.P.)
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA;
| | - Bibi Zhou
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (C.S.C.); (B.Z.); (S.A.); (R.T.P.)
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA;
| | - Silke Andresen
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (C.S.C.); (B.Z.); (S.A.); (R.T.P.)
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA;
| | - Robert T. Patry
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (C.S.C.); (B.Z.); (S.A.); (R.T.P.)
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA;
| | - Artur Muszyński
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA;
| | - Craig T. Parker
- Produce Safety and Microbiology Research Unit, Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA 94710, USA;
| | - Kerry K. Cooper
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ 85721, USA;
| | - Christine M. Szymanski
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (C.S.C.); (B.Z.); (S.A.); (R.T.P.)
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA;
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36
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Rangel K, Chagas TPG, De-Simone SG. Acinetobacter baumannii Infections in Times of COVID-19 Pandemic. Pathogens 2021; 10:pathogens10081006. [PMID: 34451470 PMCID: PMC8399974 DOI: 10.3390/pathogens10081006] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 12/15/2022] Open
Abstract
The COVID-19 pandemic has generated an overuse of antimicrobials in critically ill patients. Acinetobacter baumannii frequently causes nosocomial infections, particularly in intensive care units (ICUs), where the incidence has increased over time. Since the WHO declared the COVID-19 pandemic on 12 March 2020, the disease has spread rapidly, and many of the patients infected with SARS-CoV-2 needed to be admitted to the ICU. Bacterial co-pathogens are commonly identified in viral respiratory infections and are important causes of morbidity and mortality. However, we cannot neglect the increased incidence of antimicrobial resistance, which may be attributed to the excess use of antimicrobial agents during the COVID-19 pandemic. Patients with COVID-19 could be vulnerable to other infections owing to multiple comorbidities with severe COVID-19, prolonged hospitalization, and SARS-CoV-2-associated immune dysfunction. These patients have acquired secondary bacterial infections or superinfections, mainly bacteremia and urinary tract infections. This review will summarize the prevalence of A. baumannii coinfection and secondary infection in patients with COVID-19.
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Affiliation(s)
- Karyne Rangel
- FIOCRUZ, Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation in Neglected Population Diseases (INCT-IDPN), Rio de Janeiro 21040-900, Brazil
- Correspondence: (K.R.); (S.G.D.-S.); Tel.: +55-213865-8240 (K.R. & S.G.D.-S.)
| | | | - Salvatore Giovanni De-Simone
- FIOCRUZ, Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation in Neglected Population Diseases (INCT-IDPN), Rio de Janeiro 21040-900, Brazil
- Department of Molecular and Cellular Biology, Biology Institute, Federal Fluminense University, Niterói 24220-008, Brazil
- Correspondence: (K.R.); (S.G.D.-S.); Tel.: +55-213865-8240 (K.R. & S.G.D.-S.)
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37
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Cameranesi MM, Kurth D, Repizo GD. Acinetobacter defence mechanisms against biological aggressors and their use as alternative therapeutic applications. Crit Rev Microbiol 2021; 48:21-41. [PMID: 34289313 DOI: 10.1080/1040841x.2021.1939266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Several Acinetobacter strains are important nosocomial pathogens, with Acinetobacter baumannii being the species of greatest worldwide concern due to its multi-drug resistance and the recent appearance of hyper-virulent strains in the clinical setting. Colonisation of this environment is associated with a multitude of bacterial factors, and the molecular features that promote environmental persistence in abiotic surfaces, including intrinsic desiccation resistance, biofilm formation and motility, have been previously addressed. On the contrary, mechanisms enabling Acinetobacter spp. survival when faced against other biological competitors are starting to be characterised. Among them, secretion systems (SS) of different types, such as the T5bSS (Contact-dependent inhibition systems) and the T6SS, confer adaptive advantages against bacterial aggressors. Regarding mechanisms of defence against bacteriophages, such as toxin-antitoxin, restriction-modification, Crispr-Cas and CBASS, among others, have been identified but remain poorly characterised. In view of this, we aimed to summarise the present knowledge on defence mechanisms that enable niche establishment in members of the Acinetobacter genus. Different proposals are also described for the use of some components of these systems as molecular tools to treat Acinetobacter infections.
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Affiliation(s)
- María Marcela 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
| | - Daniel Kurth
- Planta Piloto de Procesos Industriales Microbiológicos (PROIMI, CONICET), San Miguel de Tucumán, Argentina
| | - Guillermo Daniel 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
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Pepi M, Focardi S. Antibiotic-Resistant Bacteria in Aquaculture and Climate Change: A Challenge for Health in the Mediterranean Area. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:5723. [PMID: 34073520 PMCID: PMC8198758 DOI: 10.3390/ijerph18115723] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/11/2021] [Accepted: 05/22/2021] [Indexed: 12/30/2022]
Abstract
Aquaculture is the productive activity that will play a crucial role in the challenges of the millennium, such as the need for proteins that support humans and the respect for the environment. Aquaculture is an important economic activity in the Mediterranean basin. A great impact is presented, however, by aquaculture practices as they involve the use of antibiotics for treatment and prophylaxis. As a consequence of the use of antibiotics in aquaculture, antibiotic resistance is induced in the surrounding bacteria in the column water, sediment, and fish-associated bacterial strains. Through horizontal gene transfer, bacteria can diffuse antibiotic-resistance genes and mobile resistance genes further spreading genetic determinants. Once triggered, antibiotic resistance easily spreads among aquatic microbial communities and, from there, can reach human pathogenic bacteria, making vain the use of antibiotics for human health. Climate change claims a significant role in this context, as rising temperatures can affect cell physiology in bacteria in the same way as antibiotics, causing antibiotic resistance to begin with. The Mediterranean Sea represents a 'hot spot' in terms of climate change and aspects of antibiotic resistance in aquaculture in this area can be significantly amplified, thus increasing threats to human health. Practices must be adopted to counteract negative impacts on human health, with a reduction in the use of antibiotics as a pivotal point. In the meantime, it is necessary to act against climate change by reducing anthropogenic impacts, for example by reducing CO2 emissions into the atmosphere. The One Health type approach, which involves the intervention of different skills, such as veterinary, ecology, and medicine in compliance with the principles of sustainability, is necessary and strongly recommended to face these important challenges for human and animal health, and for environmental safety in the Mediterranean area.
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Affiliation(s)
- Milva Pepi
- Stazione Zoologica Anton Dohrn, Fano Marine Centre, Viale Adriatico 1-N, 61032 Fano, Italy;
| | - Silvano Focardi
- Department of Environmental Sciences, Università di Siena, Via Mattioli, 4, 53100 Siena, Italy
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Luo CH, Hsu YH, Wu WJ, Chang KC, Yeh CS. Phage Digestion of a Bacterial Capsule Imparts Resistance to Two Antibiotic Agents. Microorganisms 2021; 9:microorganisms9040794. [PMID: 33920206 PMCID: PMC8069232 DOI: 10.3390/microorganisms9040794] [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: 03/19/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 01/10/2023] Open
Abstract
Bacteriophages are viruses that infect bacteria, replicating and multiplying using host resources. For specific infections, bacteriophages have developed extraordinary proteins for recognizing and degrading their host. Inspired by the remarkable development of viral proteins, we used the tail fiber protein to treat multiple drug-resistant Acinetobacter baumannii. The tail fiber protein exhibits polysaccharide depolymerases activity which specifically degrades exopolysaccharide (EPS) during the phage–host interaction. However, EPS-degraded cells are observed altering host susceptibility to bacterial lysis peptide, the endolysin-derived peptide. Notably, endolysin is necessary in the process of progeny liberation by breaking the bacterial cell wall. Surprisingly, peeling the EPS animated host to resist colistin, the last-resort antibiotic used in multidrug-resistant Gram-negative bacteria infection. Tail fiber-modified cell wall reduces colistin attachment, causing temporary antibiotic-resistance and possibly raising clinical risks in treating multiple drug-resistant A. baumannii.
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Affiliation(s)
- Cheng-Hung Luo
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan;
- Center of Applied Nanomedicine, National Cheng Kung University, Tainan 701, Taiwan
- Correspondence: (C.-H.L.); (K.-C.C.); (C.-S.Y.)
| | - Ya-Han Hsu
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan;
| | - Wen-Jui Wu
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien 970, Taiwan;
| | - Kai-Chih Chang
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien 970, Taiwan;
- Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien 970, Taiwan
- Correspondence: (C.-H.L.); (K.-C.C.); (C.-S.Y.)
| | - Chen-Sheng Yeh
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan;
- Center of Applied Nanomedicine, National Cheng Kung University, Tainan 701, Taiwan
- Correspondence: (C.-H.L.); (K.-C.C.); (C.-S.Y.)
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Acinetobacter baumannii: An Ancient Commensal with Weapons of a Pathogen. Pathogens 2021; 10:pathogens10040387. [PMID: 33804894 PMCID: PMC8063835 DOI: 10.3390/pathogens10040387] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 12/22/2022] Open
Abstract
Acinetobacter baumannii is regarded as a life-threatening pathogen associated with community-acquired and nosocomial infections, mainly pneumonia. The rise in the number of A. baumannii antibiotic-resistant strains reduces effective therapies and increases mortality. Bacterial comparative genomic studies have unraveled the innate and acquired virulence factors of A. baumannii. These virulence factors are involved in antibiotic resistance, environmental persistence, host-pathogen interactions, and immune evasion. Studies on host–pathogen interactions revealed that A. baumannii evolved different mechanisms to adhere to in order to invade host respiratory cells as well as evade the host immune system. In this review, we discuss current data on A. baumannii genetic features and virulence factors. An emphasis is given to the players in host–pathogen interaction in the respiratory tract. In addition, we report recent investigations into host defense systems using in vitro and in vivo models, providing new insights into the innate immune response to A. baumannii infections. Increasing our knowledge of A. baumannii pathogenesis may help the development of novel therapeutic strategies based on anti-adhesive, anti-virulence, and anti-cell to cell signaling pathways drugs.
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