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Hu X, Li D, Li H, Piao Y, Wan H, Zhou T, Karimi M, Zhao X, Li Y, Shi L, Liu Y. Reaction-Induced Self-Assembly of Polymyxin Mitigates Cytotoxicity and Reverses Drug Resistance. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2406156. [PMID: 39022883 DOI: 10.1002/adma.202406156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/07/2024] [Indexed: 07/20/2024]
Abstract
Polymyxins have been regarded as an efficient therapeutic against many life-threatening, multidrug resistant Gram-negative bacterial infections; however, the cytotoxicity and emergence of drug resistance associated with polymyxins have greatly hindered their clinical potential. Herein, the reaction-induced self-assembly (RISA) of polymyxins and natural aldehydes in aqueous solution is presented. The resulting assemblies effectively mask the positively charged nature of polymyxins, reducing their cytotoxicity. Moreover, the representative PMBA4 (composed of polymyxin B (PMB) and (E)-2-heptenal (A4)) assemblies demonstrate enhanced binding to Gram-negative bacterial outer membranes and exhibit multiple antimicrobial mechanisms, including increased membrane permeability, elevated bacterial metabolism, suppression of quorum sensing, reduced ATP synthesis, and potential reduction of bacterial drug resistance. Remarkably, PMBA4 assemblies reverse drug resistance in clinically isolated drug-resistant strains of Gram-negative bacteria, demonstrating exceptional efficacy in preventing and eradicating bacterial biofilms. PMBA4 assemblies efficiently eradicate Gram-negative bacterial biofilm infections in vivo and alleviate inflammatory response. This RISA strategy offers a practical and clinically applicable approach to minimize side effects, reverse drug resistance, and prevent the emergence of resistance associated with free polymyxins.
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Affiliation(s)
- Xiaowen Hu
- Joint Centre of Translational Medicine, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
- Department of Orthodontics School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, 325027, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, China
| | - Dongdong Li
- Joint Centre of Translational Medicine, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, China
| | - Huaping Li
- Joint Centre of Translational Medicine, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, China
| | - Yinzi Piao
- Joint Centre of Translational Medicine, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, China
| | - Hongping Wan
- Center for Sustainable Antimicrobials, Department of Pharmacy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Tieli Zhou
- Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Department of Clinical Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Mahdi Karimi
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, 1449614535, Iran
| | - Xinghong Zhao
- Center for Sustainable Antimicrobials, Department of Pharmacy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yuanfeng Li
- Joint Centre of Translational Medicine, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Linqi Shi
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China
| | - Yong Liu
- Joint Centre of Translational Medicine, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, China
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China
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2
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Tajer L, Paillart JC, Dib H, Sabatier JM, Fajloun Z, Abi Khattar Z. Molecular Mechanisms of Bacterial Resistance to Antimicrobial Peptides in the Modern Era: An Updated Review. Microorganisms 2024; 12:1259. [PMID: 39065030 PMCID: PMC11279074 DOI: 10.3390/microorganisms12071259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 06/10/2024] [Accepted: 06/18/2024] [Indexed: 07/28/2024] Open
Abstract
Antimicrobial resistance (AMR) poses a serious global health concern, resulting in a significant number of deaths annually due to infections that are resistant to treatment. Amidst this crisis, antimicrobial peptides (AMPs) have emerged as promising alternatives to conventional antibiotics (ATBs). These cationic peptides, naturally produced by all kingdoms of life, play a crucial role in the innate immune system of multicellular organisms and in bacterial interspecies competition by exhibiting broad-spectrum activity against bacteria, fungi, viruses, and parasites. AMPs target bacterial pathogens through multiple mechanisms, most importantly by disrupting their membranes, leading to cell lysis. However, bacterial resistance to host AMPs has emerged due to a slow co-evolutionary process between microorganisms and their hosts. Alarmingly, the development of resistance to last-resort AMPs in the treatment of MDR infections, such as colistin, is attributed to the misuse of this peptide and the high rate of horizontal genetic transfer of the corresponding resistance genes. AMP-resistant bacteria employ diverse mechanisms, including but not limited to proteolytic degradation, extracellular trapping and inactivation, active efflux, as well as complex modifications in bacterial cell wall and membrane structures. This review comprehensively examines all constitutive and inducible molecular resistance mechanisms to AMPs supported by experimental evidence described to date in bacterial pathogens. We also explore the specificity of these mechanisms toward structurally diverse AMPs to broaden and enhance their potential in developing and applying them as therapeutics for MDR bacteria. Additionally, we provide insights into the significance of AMP resistance within the context of host-pathogen interactions.
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Affiliation(s)
- Layla Tajer
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Department of Cell Culture, EDST, Lebanese University, Tripoli 1300, Lebanon; (L.T.); (Z.F.)
| | - Jean-Christophe Paillart
- CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Université de Strasbourg, 2 Allée Konrad Roentgen, F-67000 Strasbourg, France;
| | - Hanna Dib
- College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait;
| | - Jean-Marc Sabatier
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Université, 13385 Marseille, France
| | - Ziad Fajloun
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Department of Cell Culture, EDST, Lebanese University, Tripoli 1300, Lebanon; (L.T.); (Z.F.)
- Department of Biology, Faculty of Sciences 3, Lebanese University, Campus Michel Slayman Ras Maska, Tripoli 1352, Lebanon
| | - Ziad Abi Khattar
- Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, P.O. Box 100, Tripoli, Lebanon
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3
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Anek P, Kumpangcum S, Roytrakul S, Khanongnuch C, Saenjum C, Phannachet K. Antibacterial Activities of Phenolic Compounds in Miang Extract: Growth Inhibition and Change in Protein Expression of Extensively Drug-Resistant Klebsiella pneumoniae. Antibiotics (Basel) 2024; 13:536. [PMID: 38927202 PMCID: PMC11201136 DOI: 10.3390/antibiotics13060536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/04/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
The rising incidence of extensively drug-resistant (XDR) Klebsiella pneumoniae, including carbapenem- and colistin-resistant strains, leads to the limitation of available effective antibiotics. Miang, known as chewing tea, is produced from Camellia sinensis var. assamica or Assam tea leaves fermentation. Previous studies revealed that the extract of Miang contains various phenolic and flavonoid compounds with numerous biological activities including antibacterial activity. However, the antibacterial activity of Miang against XDR bacteria especially colistin-resistant strains had not been investigated. In this study, the compositions of phenolic and flavonoid compounds in fresh, steamed, and fermented Assam tea leaves were examined by HPLC, and their antibacterial activities were evaluated by the determination of the MIC and MBC. Pyrogallol was detected only in the extract from Miang and showed the highest activities with an MIC of 0.25 mg/mL and an MBC of 0.25-0.5 mg/mL against methicillin-susceptible Staphylococcus aureus, methicillin-resistant S. aureus, Escherichia coli ATCC 25922, colistin-resistant E. coli, and colistin-resistant K. pneumoniae. The effects on morphology and proteomic changes in K. pneumoniae NH54 treated with Miang extract were characterized by SEM and label-free quantitative shotgun proteomics analysis. The results revealed that Miang extract caused the decrease in bacterial cell wall integrity and cell lysis. The up- and downregulated expression with approximately a 2 to >5-fold change in proteins involved in peptidoglycan synthesis and outer membrane, carbohydrate, and amino acid metabolism were identified. These findings suggested that Miang containing pyrogallol and other secondary metabolites from fermentation has potential as an alternative candidate with an antibacterial agent or natural active pharmaceutical ingredient against XDR bacteria including colistin-resistant bacteria.
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Affiliation(s)
- Pannita Anek
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (P.A.); (S.K.)
| | - Sutita Kumpangcum
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (P.A.); (S.K.)
| | - Sittiruk Roytrakul
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Khlong Luang, Pathum Thani 12120, Thailand;
| | - Chartchai Khanongnuch
- Research Center for Innovation in Analytical Science and Technology for Biodiversity-Based Economic and Society (I-ANALY-S-T_B.BES-CMU), Chiang Mai University, Chiang Mai 50200, Thailand;
- Research Center for Multidisciplinary Approaches to Miang, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Chalermpong Saenjum
- Research Center for Innovation in Analytical Science and Technology for Biodiversity-Based Economic and Society (I-ANALY-S-T_B.BES-CMU), Chiang Mai University, Chiang Mai 50200, Thailand;
- Research Center for Multidisciplinary Approaches to Miang, Chiang Mai University, Chiang Mai 50200, Thailand
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Kulwadee Phannachet
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (P.A.); (S.K.)
- Research Center for Innovation in Analytical Science and Technology for Biodiversity-Based Economic and Society (I-ANALY-S-T_B.BES-CMU), Chiang Mai University, Chiang Mai 50200, Thailand;
- Research Center for Multidisciplinary Approaches to Miang, Chiang Mai University, Chiang Mai 50200, Thailand
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4
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Padhy I, Dwibedy SK, Mohapatra SS. A molecular overview of the polymyxin-LPS interaction in the context of its mode of action and resistance development. Microbiol Res 2024; 283:127679. [PMID: 38508087 DOI: 10.1016/j.micres.2024.127679] [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: 07/31/2023] [Revised: 03/03/2024] [Accepted: 03/06/2024] [Indexed: 03/22/2024]
Abstract
With the rising incidences of antimicrobial resistance (AMR) and the diminishing options of novel antimicrobial agents, it is paramount to decipher the molecular mechanisms of action and the emergence of resistance to the existing drugs. Polymyxin, a cationic antimicrobial lipopeptide, is used to treat infections by Gram-negative bacterial pathogens as a last option. Though polymyxins were identified almost seventy years back, their use has been restricted owing to toxicity issues in humans. However, their clinical use has been increasing in recent times resulting in the rise of polymyxin resistance. Moreover, the detection of "mobile colistin resistance (mcr)" genes in the environment and their spread across the globe have complicated the scenario. The mechanism of polymyxin action and the development of resistance is not thoroughly understood. Specifically, the polymyxin-bacterial lipopolysaccharide (LPS) interaction is a challenging area of investigation. The use of advanced biophysical techniques and improvement in molecular dynamics simulation approaches have furthered our understanding of this interaction, which will help develop polymyxin analogs with better bactericidal effects and lesser toxicity in the future. In this review, we have delved deeper into the mechanisms of polymyxin-LPS interactions, highlighting several models proposed, and the mechanisms of polymyxin resistance development in some of the most critical Gram-negative pathogens.
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Affiliation(s)
- Indira Padhy
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India
| | - Sambit K Dwibedy
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India
| | - Saswat S Mohapatra
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India.
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5
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Kelly SD, Duong NH, Nothof JT, Lowary TL, Whitfield C. Three-component systems represent a common pathway for extracytoplasmic addition of pentofuranose sugars into bacterial glycans. Proc Natl Acad Sci U S A 2024; 121:e2402554121. [PMID: 38748580 PMCID: PMC11127046 DOI: 10.1073/pnas.2402554121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 04/18/2024] [Indexed: 05/27/2024] Open
Abstract
Cell surface glycans are major drivers of antigenic diversity in bacteria. The biochemistry and molecular biology underpinning their synthesis are important in understanding host-pathogen interactions and for vaccine development with emerging chemoenzymatic and glycoengineering approaches. Structural diversity in glycostructures arises from the action of glycosyltransferases (GTs) that use an immense catalog of activated sugar donors to build the repeating unit and modifying enzymes that add further heterogeneity. Classical Leloir GTs incorporate α- or β-linked sugars by inverting or retaining mechanisms, depending on the nucleotide sugar donor. In contrast, the mechanism of known ribofuranosyltransferases is confined to β-linkages, so the existence of α-linked ribofuranose in some glycans dictates an alternative strategy. Here, we use Citrobacter youngae O1 and O2 lipopolysaccharide O antigens as prototypes to describe a widespread, versatile pathway for incorporating side-chain α-linked pentofuranoses by extracytoplasmic postpolymerization glycosylation. The pathway requires a polyprenyl phosphoribose synthase to generate a lipid-linked donor, a MATE-family flippase to transport the donor to the periplasm, and a GT-C type GT (founding the GT136 family) that performs the final glycosylation reaction. The characterized system shares similarities, but also fundamental differences, with both cell wall arabinan biosynthesis in mycobacteria, and periplasmic glucosylation of O antigens first discovered in Salmonella and Shigella. The participation of auxiliary epimerases allows the diversification of incorporated pentofuranoses. The results offer insight into a broad concept in microbial glycobiology and provide prototype systems and bioinformatic guides that facilitate discovery of further examples from diverse species, some in currently unknown glycans.
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Affiliation(s)
- Steven D. Kelly
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | - Nam Ha Duong
- Institute of Biological Chemistry, Academia Sinica, Nangang, Taipei11529, Taiwan
- Chemical Biology and Molecular Biophysics, Taiwan International Graduate Program, Academia Sinica, Nangang, Taipei11529, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu300044, Taiwan
| | - Jeremy T. Nothof
- Department of Chemistry, University of Alberta, Edmonton, ABT6G 2G2, Canada
| | - Todd L. Lowary
- Institute of Biological Chemistry, Academia Sinica, Nangang, Taipei11529, Taiwan
- Department of Chemistry, University of Alberta, Edmonton, ABT6G 2G2, Canada
- Institute of Biochemical Sciences, National Taiwan University, Taipei10617, Taiwan
| | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
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6
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Baijal K, Abramchuk I, Herrera CM, Mah TF, Trent MS, Lavallée-Adam M, Downey M. Polyphosphate kinase regulates LPS structure and polymyxin resistance during starvation in E. coli. PLoS Biol 2024; 22:e3002558. [PMID: 38478588 PMCID: PMC10962826 DOI: 10.1371/journal.pbio.3002558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 03/25/2024] [Accepted: 02/21/2024] [Indexed: 03/26/2024] Open
Abstract
Polyphosphates (polyP) are chains of inorganic phosphates that can reach over 1,000 residues in length. In Escherichia coli, polyP is produced by the polyP kinase (PPK) and is thought to play a protective role during the response to cellular stress. However, the molecular pathways impacted by PPK activity and polyP accumulation remain poorly characterized. In this work, we used label-free mass spectrometry to study the response of bacteria that cannot produce polyP (Δppk) during starvation to identify novel pathways regulated by PPK. In response to starvation, we found 92 proteins significantly differentially expressed between wild-type and Δppk mutant cells. Wild-type cells were enriched for proteins related to amino acid biosynthesis and transport, while Δppk mutants were enriched for proteins related to translation and ribosome biogenesis, suggesting that without PPK, cells remain inappropriately primed for growth even in the absence of the required building blocks. From our data set, we were particularly interested in Arn and EptA proteins, which were down-regulated in Δppk mutants compared to wild-type controls, because they play a role in lipid A modifications linked to polymyxin resistance. Using western blotting, we confirm differential expression of these and related proteins in K-12 strains and a uropathogenic isolate, and provide evidence that this mis-regulation in Δppk cells stems from a failure to induce the BasRS two-component system during starvation. We also show that Δppk mutants unable to up-regulate Arn and EptA expression lack the respective L-Ara4N and pEtN modifications on lipid A. In line with this observation, loss of ppk restores polymyxin sensitivity in resistant strains carrying a constitutively active basR allele. Overall, we show a new role for PPK in lipid A modification during starvation and provide a rationale for targeting PPK to sensitize bacteria towards polymyxin treatment. We further anticipate that our proteomics work will provide an important resource for researchers interested in the diverse pathways impacted by PPK.
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Affiliation(s)
- Kanchi Baijal
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Iryna Abramchuk
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Carmen M. Herrera
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Thien-Fah Mah
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Ontario, Canada
| | - M. Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Mathieu Lavallée-Adam
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Michael Downey
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Nwabor OF, Chukamnerd A, Terbtothakun P, Nwabor LC, Surachat K, Roytrakul S, Voravuthikunchai SP, Chusri S. Synergistic effects of polymyxin and vancomycin combinations on carbapenem- and polymyxin-resistant Klebsiella pneumoniae and their molecular characteristics. Microbiol Spectr 2023; 11:e0119923. [PMID: 37905823 PMCID: PMC10715205 DOI: 10.1128/spectrum.01199-23] [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: 04/05/2023] [Accepted: 09/27/2023] [Indexed: 11/02/2023] Open
Abstract
IMPORTANCE This study provides insights into the mechanisms of polymyxin resistance in K. pneumoniae clinical isolates and demonstrates potential strategies of polymyxin and vancomycin combinations for combating this resistance. We also identified possible mechanisms that might be associated with the treatment of these combinations against carbapenem- and polymyxin-resistant K. pneumoniae clinical isolates. The findings have significant implications for the development of alternative therapies and the effective management of infections caused by these pathogens.
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Affiliation(s)
- Ozioma Forstinus Nwabor
- Division of Infectious Diseases, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Arnon Chukamnerd
- Division of Infectious Diseases, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Pawarisa Terbtothakun
- Division of Biological Science, Faculty of Science and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Lois Chinwe Nwabor
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Komwit Surachat
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
- Faculty of Medicine, Translational Medicine Research Center, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Sittiruk Roytrakul
- Functional Proteomics Technology Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | - Supayang Piyawan Voravuthikunchai
- Faculty of Science, Center of Antimicrobial Biomaterial Innovation-Southeast Asia and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Sarunyou Chusri
- Division of Infectious Diseases, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
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Liang Z, Huang L, Liu H, Zheng Y, Feng J, Shi Z, Chen Y, Lv M, Zhou J, Zhang L, Chen S. Characterization of the Arn lipopolysaccharide modification system essential for zeamine resistance unveils its new roles in Dickeya oryzae physiology and virulence. MOLECULAR PLANT PATHOLOGY 2023; 24:1480-1494. [PMID: 37740253 PMCID: PMC10632790 DOI: 10.1111/mpp.13386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/14/2023] [Accepted: 08/22/2023] [Indexed: 09/24/2023]
Abstract
The zeamines produced by Dickeya oryzae are potent polyamine antibiotics and phytotoxins that are essential for bacterial virulence. We recently showed that the RND efflux pump DesABC in D. oryzae confers partial resistance to zeamines. To fully elucidate the bacterial self-protection mechanisms, in this study we used transposon mutagenesis to identify the genes encoding proteins involved in zeamine resistance in D. oryzae EC1. This led to the identification of a seven-gene operon, arnEC1 , that encodes enzyme homologues associated with lipopolysaccharide modification. Deletion of the arnEC1 genes in strain EC1 compromised its zeamine resistance 8- to 16-fold. Further deletion of the des gene in the arnEC1 mutant background reduced zeamine resistance to a level similar to that of the zeamine-sensitive Escherichia coli DH5α. Intriguingly, the arnEC1 mutants showed varied bacterial virulence on rice, potato, and Chinese cabbage. Further analyses demonstrated that ArnBCATEC1 are involved in maintenance of the bacterial nonmucoid morphotype by repressing the expression of capsular polysaccharide genes and that ArnBEC1 is a bacterial virulence determinant, influencing transcriptional expression of over 650 genes and playing a key role in modulating bacterial motility and virulence. Taken together, these findings decipher a novel zeamine resistance mechanism in D. oryzae and document new roles of the Arn enzymes in modulation of bacterial physiology and virulence.
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Affiliation(s)
- Zhibin Liang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
| | - Luhao Huang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
| | - Huidi Liu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
| | - Ying Zheng
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
| | - Jiani Feng
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
| | - Zurong Shi
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- School of Biological EngineeringHuainan Normal UniversityHuainanChina
| | - Yufan Chen
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Research Center of Chinese Herbal Resource Science and EngineeringGuangzhou University of Chinese MedicineGuangzhouChina
| | - Mingfa Lv
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- College of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhouChina
| | - Jianuan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
| | - Lian‐Hui Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
| | - Shaohua Chen
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
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9
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Shahzad S, Willcox MDP, Rayamajhee B. A Review of Resistance to Polymyxins and Evolving Mobile Colistin Resistance Gene ( mcr) among Pathogens of Clinical Significance. Antibiotics (Basel) 2023; 12:1597. [PMID: 37998799 PMCID: PMC10668746 DOI: 10.3390/antibiotics12111597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/26/2023] [Accepted: 11/04/2023] [Indexed: 11/25/2023] Open
Abstract
The global rise in antibiotic resistance in bacteria poses a major challenge in treating infectious diseases. Polymyxins (e.g., polymyxin B and colistin) are last-resort antibiotics against resistant Gram-negative bacteria, but the effectiveness of polymyxins is decreasing due to widespread resistance among clinical isolates. The aim of this literature review was to decipher the evolving mechanisms of resistance to polymyxins among pathogens of clinical significance. We deciphered the molecular determinants of polymyxin resistance, including distinct intrinsic molecular pathways of resistance as well as evolutionary characteristics of mobile colistin resistance. Among clinical isolates, Acinetobacter stains represent a diversified evolution of resistance, with distinct molecular mechanisms of intrinsic resistance including naxD, lpxACD, and stkR gene deletion. On the other hand, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa are usually resistant via the PhoP-PhoQ and PmrA-PmrB pathways. Molecular evolutionary analysis of mcr genes was undertaken to show relative relatedness across the ten main lineages. Understanding the molecular determinants of resistance to polymyxins may help develop suitable and effective methods for detecting polymyxin resistance determinants and the development of novel antimicrobial molecules.
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Affiliation(s)
- Shakeel Shahzad
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW 2052, Australia;
| | - Mark D. P. Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW 2052, Australia;
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10
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Muñoz-Escudero D, Breazeale SD, Lee M, Guan Z, Raetz CRH, Sousa MC. Structure and Function of ArnD. A Deformylase Essential for Lipid A Modification with 4-Amino-4-deoxy-l-arabinose and Polymyxin Resistance. Biochemistry 2023; 62:2970-2981. [PMID: 37782650 PMCID: PMC10914315 DOI: 10.1021/acs.biochem.3c00293] [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] [Indexed: 10/04/2023]
Abstract
Covalent modification of lipid A with 4-deoxy-4-amino-l-arabinose (Ara4N) mediates resistance to cationic antimicrobial peptides and polymyxin antibiotics in Gram-negative bacteria. The proteins required for Ara4N biosynthesis are encoded in the pmrE and arnBCADTEF loci, with ArnT ultimately transferring the amino sugar from undecaprenyl-phospho-4-deoxy-4-amino-l-arabinose (C55P-Ara4N) to lipid A. However, Ara4N is N-formylated prior to its transfer to undecaprenyl-phosphate by ArnC, requiring a deformylase activity downstream in the pathway to generate the final C55P-Ara4N donor. Here, we show that deletion of the arnD gene in an Escherichia coli mutant that constitutively expresses the arnBCADTEF operon leads to accumulation of the formylated ArnC product undecaprenyl-phospho-4-deoxy-4-formamido-l-arabinose (C55P-Ara4FN), suggesting that ArnD is the downstream deformylase. Purification of Salmonella typhimurium ArnD (stArnD) shows that it is membrane-associated. We present the crystal structure of stArnD revealing a NodB homology domain structure characteristic of the metal-dependent carbohydrate esterase family 4 (CE4). However, ArnD displays several distinct features: a 44 amino acid insertion, a C-terminal extension in the NodB fold, and sequence divergence in the five motifs that define the CE4 family, suggesting that ArnD represents a new family of carbohydrate esterases. The insertion is responsible for membrane association as its deletion results in a soluble ArnD variant. The active site retains a metal coordination H-H-D triad, and in the presence of Co2+ or Mn2+, purified stArnD efficiently deformylates C55P-Ara4FN confirming its role in Ara4N biosynthesis. Mutations D9N and H233Y completely inactivate stArnD implicating these two residues in a metal-assisted acid-base catalytic mechanism.
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Affiliation(s)
- Daniel Muñoz-Escudero
- Department of Molecular Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309
| | - Steven D. Breazeale
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710
| | - Myeongseon Lee
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710
| | | | - Marcelo C. Sousa
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309
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11
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Riquelme MP, Martinez RW, Brito B, García P, Legarraga P, Wozniak A. Chromosome-Mediated Colistin Resistance in Clinical Isolates of Klebsiella pneumoniae and Escherichia coli: Mutation Analysis in the Light of Genetic Background. Infect Drug Resist 2023; 16:6451-6462. [PMID: 37789836 PMCID: PMC10544214 DOI: 10.2147/idr.s427398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 08/10/2023] [Indexed: 10/05/2023] Open
Abstract
Purpose Colistin resistance mechanisms involving mutations in chromosomal genes associated with LPS modification are not completely understood. Mutations in genes coding for the MgrB regulator frequently account for colistin resistance in Klebsiella pneumoniae, whereas mutations in genes coding for PhoPQ and PmrAB are frequent in E. coli. Our aim was to perform a genetic analysis of chromosomal mutations in colistin-resistant (MIC ≥4 µg/mL) clinical isolates of K. pneumoniae (n = 8) and E. coli (n = 7) of different STs. Methods Isolates were obtained in a 3-year period in a university hospital in Santiago, Chile. Susceptibility to colistin, aminoglycosides, cephalosporins, carbapenems and ciprofloxacin was determined through broth microdilution. Whole genome sequencing was performed for all isolates and chromosomal gene sequences were compared with sequences of colistin-susceptible isolates of the same sequence types. Results None of the isolates carried mcr genes. Most of the isolates were susceptible to all the antibiotics analyzed. E. coli isolates were ST69, ST127, ST59, ST131 and ST14, and K. pneumoniae isolates were ST454, ST45, ST6293, ST380 and ST25. All the isolates had mutations in chromosomal genes analyzed. K. pneumoniae had mutations mainly in mgrB gene, whereas E. coli had mutations in pmrA, pmrB and pmrE genes. Most of the amino acid changes in LPS-modifying enzymes of colistin-resistant isolates were found in colistin-susceptible isolates of the same and/or different ST. Eleven of them were found only in colistin-resistant isolates. Conclusion Colistin resistance mechanisms depend on genetic background, and are due to chromosomal mutations, which implies a lower risk of transmission than plasmid-mediated genes. Colistin resistance is not associated with multidrug-resistance, nor to high-risk sequence types.
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Affiliation(s)
- María Paz Riquelme
- Department of Clinical Laboratories - School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rodrigo W Martinez
- Genomics & Resistant Microbes Group (Germ) - Instituto de Ciencias e Innovación en Medicina (ICIM); School of Medicine-Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
- Millennium Nucleus for Collaborative Research on Bacterial Resistance (MICROB-R), SantiagoChile
| | - Bárbara Brito
- Australian Institute for Microbiology & Infection - Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Patricia García
- Department of Clinical Laboratories - School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Nucleus for Collaborative Research on Bacterial Resistance (MICROB-R), SantiagoChile
- Clinical Laboratories Network, Red de Salud UC-CHRISTUS, Santiago, Chile
| | - Paulette Legarraga
- Department of Clinical Laboratories - School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Clinical Laboratories Network, Red de Salud UC-CHRISTUS, Santiago, Chile
| | - Aniela Wozniak
- Department of Clinical Laboratories - School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Nucleus for Collaborative Research on Bacterial Resistance (MICROB-R), SantiagoChile
- Clinical Laboratories Network, Red de Salud UC-CHRISTUS, Santiago, Chile
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12
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Mitchell ME, Gatzeva-Topalova PZ, Bargmann AD, Sammakia T, Sousa MC. Targeting the Conformational Change in ArnA Dehydrogenase for Selective Inhibition of Polymyxin Resistance. Biochemistry 2023; 62:2216-2227. [PMID: 37410993 PMCID: PMC10914316 DOI: 10.1021/acs.biochem.3c00227] [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] [Indexed: 07/08/2023]
Abstract
Polymyxins are important last resort antibiotics for the treatment of infections caused by multidrug-resistant Gram-negative pathogens. However, pathogens have acquired resistance to polymyxins through a pathway that modifies lipid A with 4-amino-4-deoxy-l-arabinose (Ara4N). Inhibition of this pathway is, therefore, a desirable strategy to combat polymyxin resistance. The first pathway-specific reaction is an NAD+-dependent oxidative decarboxylation of UDP-glucuronic acid (UDP-GlcA) catalyzed by the dehydrogenase domain of ArnA (ArnA_DH). We present the crystal structure of Salmonella enterica serovar typhimurium ArnA in complex with UDP-GlcA showing that binding of the sugar nucleotide is sufficient to trigger a conformational change conserved in bacterial ArnA_DHs but absent in its human homologs, as confirmed by structure and sequence analysis. Ligand binding assays show that the conformational change is essential for NAD+ binding and catalysis. Enzyme activity and binding assays show that (i) UDP-GlcA analogs lacking the 6' carboxylic acid bind the enzyme but fail to trigger the conformational change, resulting in poor inhibition, and (ii) the uridine monophosphate moiety of the substrate provides most of the ligand binding energy. Mutation of asparagine 492 to alanine (N492A) disrupts the ability of ArnA_DH to undergo the conformational change while retaining substrate binding, suggesting that N492 is involved in sensing the 6' carboxylate in the substrate. These results identify the UDP-GlcA-induced conformational change in ArnA_DH as an essential mechanistic step in bacterial enzymes, providing a platform for selective inhibition.
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Affiliation(s)
- Megan E. Mitchell
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309
| | | | - Austin D. Bargmann
- Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Tarek Sammakia
- Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Marcelo C. Sousa
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309
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13
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Baijal K, Abramchuk I, Herrera CM, Stephen Trent M, Lavallée-Adam M, Downey M. Proteomics analysis reveals a role for E. coli polyphosphate kinase in membrane structure and polymyxin resistance during starvation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.06.546892. [PMID: 37461725 PMCID: PMC10350021 DOI: 10.1101/2023.07.06.546892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Polyphosphates (polyP) are chains of inorganic phosphates that can reach over 1000 residues in length. In Escherichia coli, polyP is produced by the polyP kinase (PPK) and is thought to play a protective role during the response to cellular stress. However, the molecular pathways impacted by PPK activity and polyP accumulation remain poorly characterized. In this work we used label-free mass spectrometry to study the response of bacteria that cannot produce polyP (∆ppk) during starvation to identify novel pathways regulated by PPK. In response to starvation, we found 92 proteins significantly differentially expressed between wild-type and ∆ppk mutant cells. Wild-type cells were enriched for proteins related to amino acid biosynthesis and transport, while Δppk mutants were enriched for proteins related to translation and ribosome biogenesis, suggesting that without PPK, cells remain inappropriately primed for growth even in the absence of required building blocks. From our dataset, we were particularly interested in Arn and EptA proteins, which were downregulated in ∆ppk mutants compared to wild-type controls, because they play a role in lipid A modifications linked to polymyxin resistance. Using western blotting, we confirm differential expression of these and related proteins, and provide evidence that this mis-regulation in ∆ppk cells stems from a failure to induce the BasS/BasR two-component system during starvation. We also show that ∆ppk mutants unable to upregulate Arn and EptA expression lack the respective L-Ara4N and pEtN modifications on lipid A. In line with this observation, loss of ppk restores polymyxin sensitivity in resistant strains carrying a constitutively active basR allele. Overall, we show a new role for PPK in lipid A modification during starvation and provide a rationale for targeting PPK to sensitize bacteria towards polymyxin treatment. We further anticipate that our proteomics work will provide an important resource for researchers interested in the diverse pathways impacted by PPK.
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Affiliation(s)
- Kanchi Baijal
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Iryna Abramchuk
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Carmen M. Herrera
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - M. Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Mathieu Lavallée-Adam
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Michael Downey
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
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14
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Carfrae LA, Rachwalski K, French S, Gordzevich R, Seidel L, Tsai CN, Tu MM, MacNair CR, Ovchinnikova OG, Clarke BR, Whitfield C, Brown ED. Inhibiting fatty acid synthesis overcomes colistin resistance. Nat Microbiol 2023:10.1038/s41564-023-01369-z. [PMID: 37127701 DOI: 10.1038/s41564-023-01369-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 03/23/2023] [Indexed: 05/03/2023]
Abstract
Treating multidrug-resistant infections has increasingly relied on last-resort antibiotics, including polymyxins, for example colistin. As polymyxins are given routinely, the prevalence of their resistance is on the rise and increases mortality rates of sepsis patients. The global dissemination of plasmid-borne colistin resistance, driven by the emergence of mcr-1, threatens to diminish the therapeutic utility of polymyxins from an already shrinking antibiotic arsenal. Restoring sensitivity to polymyxins using combination therapy with sensitizing drugs is a promising approach to reviving its clinical utility. Here we describe the ability of the biotin biosynthesis inhibitor, MAC13772, to synergize with colistin exclusively against colistin-resistant bacteria. MAC13772 indirectly disrupts fatty acid synthesis (FAS) and restores sensitivity to the last-resort antibiotic, colistin. Accordingly, we found that combinations of colistin and other FAS inhibitors, cerulenin, triclosan and Debio1452-NH3, had broad potential against both chromosomal and plasmid-mediated colistin resistance in chequerboard and lysis assays. Furthermore, combination therapy with colistin and the clinically relevant FabI inhibitor, Debio1452-NH3, showed efficacy against mcr-1 positive Klebsiella pneumoniae and colistin-resistant Escherichia coli systemic infections in mice. Using chemical genomics, lipidomics and transcriptomics, we explored the mechanism of the interaction. We propose that inhibiting FAS restores colistin sensitivity by depleting lipid synthesis, leading to changes in phospholipid composition. In all, this work reveals a surprising link between FAS and colistin resistance.
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Affiliation(s)
- Lindsey A Carfrae
- Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Kenneth Rachwalski
- Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Shawn French
- Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Rodion Gordzevich
- Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Laura Seidel
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Caressa N Tsai
- Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Megan M Tu
- Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Craig R MacNair
- Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Olga G Ovchinnikova
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Bradley R Clarke
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Eric D Brown
- Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
- Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
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15
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Hanafin PO, Abdul Rahim N, Sharma R, Cess CG, Finley SD, Bergen PJ, Velkov T, Li J, Rao GG. Proof-of-concept for incorporating mechanistic insights from multi-omics analyses of polymyxin B in combination with chloramphenicol against Klebsiella pneumoniae. CPT Pharmacometrics Syst Pharmacol 2023; 12:387-400. [PMID: 36661181 PMCID: PMC10014067 DOI: 10.1002/psp4.12923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/21/2022] [Accepted: 12/30/2022] [Indexed: 01/21/2023] Open
Abstract
Carbapenemase-resistant Klebsiella pneumoniae (KP) resistant to multiple antibiotic classes necessitates optimized combination therapy. Our objective is to build a workflow leveraging omics and bacterial count data to identify antibiotic mechanisms that can be used to design and optimize combination regimens. For pharmacodynamic (PD) analysis, previously published static time-kill studies (J Antimicrob Chemother 70, 2015, 2589) were used with polymyxin B (PMB) and chloramphenicol (CHL) mono and combination therapy against three KP clinical isolates over 24 h. A mechanism-based model (MBM) was developed using time-kill data in S-ADAPT describing PMB-CHL PD activity against each isolate. Previously published results of PMB (1 mg/L continuous infusion) and CHL (Cmax : 8 mg/L; bolus q6h) mono and combination regimens were evaluated using an in vitro one-compartment dynamic infection model against a KP clinical isolate (108 CFU/ml inoculum) over 24 h to obtain bacterial samples for multi-omics analyses. The differentially expressed genes and metabolites in these bacterial samples served as input to develop a partial least squares regression (PLSR) in R that links PD responses with the multi-omics responses via a multi-omics pathway analysis. PMB efficacy was increased when combined with CHL, and the MBM described the observed PD well for all strains. The PLSR consisted of 29 omics inputs and predicted MBM PD response (R2 = 0.946). Our analysis found that CHL downregulated metabolites and genes pertinent to lipid A, hence limiting the emergence of PMB resistance. Our workflow linked insights from analysis of multi-omics data with MBM to identify biological mechanisms explaining observed PD activity in combination therapy.
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Affiliation(s)
- Patrick O Hanafin
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | | | - Rajnikant Sharma
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Colin G Cess
- Department of Biomedical Engineering Viterbi School of Engineering, University of Southern California, Los Angeles, California, USA
| | - Stacey D Finley
- Department of Biomedical Engineering Viterbi School of Engineering, University of Southern California, Los Angeles, California, USA
| | - Phillip J Bergen
- Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Tony Velkov
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jian Li
- Department of Microbiology, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences and Biomedicine Discovery Institute, Monash University, Parkville, Victoria, Australia
| | - Gauri G Rao
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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16
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Leigh RJ, McKenna C, McWade R, Lynch B, Walsh F. Comparative genomics and pangenomics of vancomycin-resistant and susceptible Enterococcus faecium from Irish hospitals. J Med Microbiol 2022; 71. [DOI: 10.1099/jmm.0.001590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Introduction.
Enterococcus faecium
has emerged as an important nosocomial pathogen, which is increasingly difficult to treat due to the genetic acquisition of vancomycin resistance. Ireland has a recalcitrant vancomycin-resistant bloodstream infection rate compared to other developed countries.
Hypothesis/Gap statement. Vancomycin resistance rates persist amongst
E. faecium
isolates from Irish hospitals. The evolutionary genomics governing these trends have not been fully elucidated.
Methodology. A set of 28 vancomycin-resistant isolates was sequenced to construct a dataset alongside 61 other publicly available Irish genomes. This dataset was extensively analysed using in silico methodologies (comparative genomics, pangenomics, phylogenetics, genotypics and comparative functional analyses) to uncover distinct evolutionary, coevolutionary and clinically relevant population trends.
Results. These results suggest that a stable (in terms of genome size, GC% and number of genes), yet genetically diverse population (in terms of gene content) of
E. faecium
persists in Ireland with acquired resistance arising via plasmid acquisition (vanA) or, to a lesser extent, chromosomal recombination (vanB). Population analysis revealed five clusters with one cluster partitioned into four clades which transcend isolation dates. Pangenomic and recombination analyses revealed an open (whole genome and chromosomal specific) pangenome illustrating a rampant evolutionary pattern. Comparative resistomics and virulomics uncovered distinct chromosomal and mobilomal propensity for multidrug resistance, widespread chromosomal point-mutation-mediated resistance and chromosomally harboured arsenals of virulence factors. Interestingly, a potential difference in biofilm formation strategies was highlighted by coevolutionary analysis, suggesting differential biofilm genotypes between vanA and vanB isolates.
Conclusions. These results highlight the evolutionary history of Irish
E. faecium
isolates and may provide insight into underlying infection dynamics in a clinical setting. Due to the apparent ease of vancomycin resistance acquisition over time, susceptible
E. faecium
should be concurrently reduced in Irish hospitals to mitigate potential resistant infections.
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Affiliation(s)
- Robert J. Leigh
- Department of Biology, Maynooth University, Mariavilla, Maynooth, Co. Kildare, Ireland
| | - Chloe McKenna
- Department of Biology, Maynooth University, Mariavilla, Maynooth, Co. Kildare, Ireland
| | - Robert McWade
- Department of Microbiology, Mater Misericordiae University Hospital, Eccles St., Dublin 7, D07 R2WY, Ireland
| | - Breda Lynch
- Department of Microbiology, Mater Misericordiae University Hospital, Eccles St., Dublin 7, D07 R2WY, Ireland
| | - Fiona Walsh
- Department of Biology, Maynooth University, Mariavilla, Maynooth, Co. Kildare, Ireland
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17
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Burata OE, Yeh TJ, Macdonald CB, Stockbridge RB. Still rocking in the structural era: A molecular overview of the small multidrug resistance (SMR) transporter family. J Biol Chem 2022; 298:102482. [PMID: 36100040 PMCID: PMC9574504 DOI: 10.1016/j.jbc.2022.102482] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/24/2022] [Accepted: 09/07/2022] [Indexed: 11/20/2022] Open
Abstract
The small multidrug resistance (SMR) family is composed of widespread microbial membrane proteins that fulfill different transport functions. Four functional SMR subtypes have been identified, which variously transport the small, charged metabolite guanidinium, bulky hydrophobic drugs and antiseptics, polyamines, and glycolipids across the membrane bilayer. The transporters possess a minimalist architecture, with ∼100-residue subunits that require assembly into homodimers or heterodimers for transport. In part because of their simple construction, the SMRs are a tractable system for biochemical and biophysical analysis. Studies of SMR transporters over the last 25 years have yielded deep insights for diverse fields, including membrane protein topology and evolution, mechanisms of membrane transport, and bacterial multidrug resistance. Here, we review recent advances in understanding the structures and functions of SMR transporters. New molecular structures of SMRs representing two of the four functional subtypes reveal the conserved structural features that have permitted the emergence of disparate substrate transport functions in the SMR family and illuminate structural similarities with a distantly related membrane transporter family, SLC35/DMT.
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Affiliation(s)
- Olive E Burata
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Trevor Justin Yeh
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Randy B Stockbridge
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA; Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA; Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA.
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18
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Mutation of PA4292 in Pseudomonas aeruginosa Increases β-Lactam Resistance through Upregulating Pyocyanin Production. Antimicrob Agents Chemother 2022; 66:e0042122. [PMID: 35695577 PMCID: PMC9295561 DOI: 10.1128/aac.00421-22] [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] [Indexed: 12/15/2022] Open
Abstract
Metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa is increasingly reported worldwide and usually causes infections with high mortality rates. Aztreonam/avibactam is a β-lactam/β-lactamase inhibitor (BLBLI) combination that is under clinical trials. The advantage of aztreonam/avibactam over the currently used BLBLIs lies in its effectiveness against MBL-producing pathogens, making it one of the few drugs that can be used to treat infections caused by MBL-producing P. aeruginosa. However, the molecular mechanisms underlying aztreonam/avibactam resistance development remain unexplored. Here, in this study, we performed an in vitro evolution assay by using a previously identified MBL-producing P. aeruginosa clinical isolate, NKPa-71, and found mutations in a novel gene, PA4292, in the aztreonam/avibactam-resistant mutants. By mutation of PA4292 in the reference strain PA14, we verified the role of PA4292 in the resistance to aztreonam/avibactam and β-lactams. Transcriptomic analyses revealed upregulation of pyocyanin biosynthesis genes among the most overexpressed in the PA4292 mutant. We further demonstrated that pyocyanin overproduction in the PA4292 mutant increased the bacterial resistance to β-lactams by reducing drug influx. These data revealed a novel mechanism that might lead to the development of resistance to aztreonam/avibactam and β-lactams.
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19
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The Role of Colistin in the Era of New β-Lactam/β-Lactamase Inhibitor Combinations. Antibiotics (Basel) 2022; 11:antibiotics11020277. [PMID: 35203879 PMCID: PMC8868358 DOI: 10.3390/antibiotics11020277] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 02/06/2023] Open
Abstract
With the current crisis related to the emergence of carbapenem-resistant Gram-negative bacteria (CR-GNB), classical treatment approaches with so-called “old-fashion antibiotics” are generally unsatisfactory. Newly approved β-lactam/β-lactamase inhibitors (BLBLIs) should be considered as the first-line treatment options for carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) infections. However, colistin can be prescribed for uncomplicated lower urinary tract infections caused by CR-GNB by relying on its pharmacokinetic and pharmacodynamic properties. Similarly, colistin can still be regarded as an alternative therapy for infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) until new and effective agents are approved. Using colistin in combination regimens (i.e., including at least two in vitro active agents) can be considered in CRAB infections, and CRE infections with high risk of mortality. In conclusion, new BLBLIs have largely replaced colistin for the treatment of CR-GNB infections. Nevertheless, colistin may be needed for the treatment of CRAB infections and in the setting where the new BLBLIs are currently unavailable. In addition, with the advent of rapid diagnostic methods and novel antimicrobials, the application of personalized medicine has gained significant importance in the treatment of CRE infections.
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20
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He Z, Yang Y, Li W, Ma X, Zhang C, Zhang J, Sun B, Ding T, Tian GB. Comparative genomic analyses of Polymyxin-resistant Enterobacteriaceae strains from China. BMC Genomics 2022; 23:88. [PMID: 35100991 PMCID: PMC8805313 DOI: 10.1186/s12864-022-08301-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 01/11/2022] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Mobile colistin resistance like gene (mcr-like gene) is a new type of polymyxin resistance gene that can be horizontally transferred in the Enterobacteriaceae. This has brought great challenges to the treatment of multidrug-resistant Escherichia coli and K. pneumoniae. RESULTS K. pneumoniae 16BU137 and E. coli 17MR471 were isolated from the bus and subway handrails in Guangzhou, China. K. pneumoniae 19PDR22 and KP20191015 were isolated from patients with urinary tract infection and severe pneumonia in Anhui, China. Sequence analysis indicated that the mcr-1.1 gene was present on the chromosome of E. coli 17MR471, and the gene was in the gene cassette containing pap2 and two copies of ISApl1.The mcr-1.1 was found in the putative IncX4 type plasmid p16BU137_mcr-1.1 of K. pneumoniae 16BU137, but ISApl1 was not found in its flanking sequence. Mcr-8 variants were found in the putative IncFIB/ IncFII plasmid pKP20191015_mcr-8 of K. pneumoniae KP20191015 and flanked by ISEcl1 and ISKpn26. CONCLUSION This study provides timely information on Enterobacteriaceae bacteria carrying mcr-like genes, and provides a reference for studying the spread of mcr-1 in China and globally.
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Affiliation(s)
- Zhien He
- Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, China
| | - Yongqiang Yang
- Department of Microbiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, 510006, China
| | - Wei Li
- Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, China
| | - Xiaoling Ma
- Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, China
| | - Changfeng Zhang
- Clinical Laboratory of the First Affiliated Hospital, Anhui University of Chinese Medicine, Hefei, 230031, Anhui, China
| | - Jingxiang Zhang
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Baolin Sun
- Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, China.
| | - Tao Ding
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China.
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
| | - Guo-Bao Tian
- Department of Microbiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China.
- Xizang Minzu University School of Medicine, Xianyang, China.
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21
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Nang SC, Li M, Harper M, Mandela E, Bergen PJ, Rolain JM, Zhu Y, Velkov T, Li J. Polymyxin causes cell envelope remodeling and stress responses in mcr-1-harboring Escherichia coli. Int J Antimicrob Agents 2021; 59:106505. [PMID: 34954369 DOI: 10.1016/j.ijantimicag.2021.106505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/11/2021] [Accepted: 12/17/2021] [Indexed: 11/28/2022]
Abstract
Polymyxins remain important last-line antibiotics against multidrug-resistant Gram-negative bacteria. Unfortunately, polymyxin resistance is emerging and the mobile polymyxin resistance gene, mcr is contributing to the wide dissemination of polymyxin resistance, especially among Escherichia coli, with mcr-1 being the most commonly found variant. The objective of this study was to provide mechanistic insights into concentration-dependent transcriptomic responses of mcr-harboring E. coli following polymyxin treatment. An mcr-1-carrying clinical isolate of E. coli (LH30) was treated with polymyxin B at 2 and 8 mg/L. Bacterial cultures were collected before and 1 h following treatment for viable counting and transcriptomic analysis. Growth of E. coli LH30 was unaffected by 2 mg/L polymyxin B, whereas killing of ∼2 log10 cfu/mL occurred with 8 mg/L at 1 h. All four phosphoethanolamine (pEtN) transferase genes (mcr-1, eptA, eptB and eptC) were upregulated (FC=2.4-4.0) by 8 mg/L polymyxin B, indicating that pEtN modifications were the preferred polymyxin resistance mechanism. The higher polymyxin B concentration also affected the expression of genes involved in fatty acid, lipopolysaccharide, lipid A, phospholipid biosynthesis, iron homeostasis and oxidative stress pathways. Our transcriptomic analysis revealed that cell envelope remodeling, pEtN modification, iron acquisition and oxidative stress protective mechanisms play a key role in the survival of mcr-carrying E. coli treated with polymyxin. These findings provide new mechanistic information at the gene expression level to counter polymyxin resistance.
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Affiliation(s)
- Sue C Nang
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Victoria, Australia
| | - Mengyao Li
- Department of Critical Care Medicine, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, China; Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, China
| | - Marina Harper
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Victoria, Australia
| | - Eric Mandela
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Victoria, Australia
| | - Phillip J Bergen
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jean-Marc Rolain
- Aix Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Faculté de Médecine et de Pharmacie, Marseille, France
| | - Yan Zhu
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Victoria, Australia
| | - Tony Velkov
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria, Australia
| | - Jian Li
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Victoria, Australia.
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22
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Masood KI, Umar S, Hasan Z, Farooqi J, Razzak SA, Jabeen N, Rao J, Shakoor S, Hasan R. Lipid A-Ara4N as an alternate pathway for (colistin) resistance in Klebsiella pneumonia isolates in Pakistan. BMC Res Notes 2021; 14:449. [PMID: 34906210 PMCID: PMC8670247 DOI: 10.1186/s13104-021-05867-3] [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: 09/29/2021] [Accepted: 11/29/2021] [Indexed: 11/23/2022] Open
Abstract
Objectives This study aimed to explore mechanism of colistin resistance amongst Klebsiella pneumoniae isolates through plasmid mediated mcr-1 gene in Pakistan. Carbapenem and Colistin resistant K. pneumoniae isolates (n = 34) stored at − 80 °C as part of the Aga Khan University Clinical Laboratory strain bank were randomly selected and subjected to mcr-1 gene PCR. To investigate mechanisms of resistance, other than plasmid mediated mcr-1 gene, whole genome sequencing was performed on 8 clinical isolates, including 6 with colistin resistance (MIC > 4 μg/ml) and 2 with intermediate resistance to colistin (MIC > 2 μg/ml). Results RT-PCR conducted revealed absence of mcr-1 gene in all isolates tested. Whole genome sequencing results revealed modifications in Lipid A-Ara4N pathway. Modifications in Lipid A-Ara4N pathway were detected in ArnA_ DH/FT, UgdH, ArnC and ArnT genes. Mutation in ArnA_ DH/FT gene were detected in S3, S5, S6 and S7 isolates. UgdH gene modifications were found in all isolates except S3, mutations in ArnC were present in all except S1, S2 and S8 and ArnT were detected in all except S4 and S7. In the absence of known mutations linked with colistin resistance, lipid pathway modifications may possibly explain the phenotype resistance to colistin, but this needs further exploration. Supplementary Information The online version contains supplementary material available at 10.1186/s13104-021-05867-3.
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Affiliation(s)
- Kiran Iqbal Masood
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Seema Umar
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Zahra Hasan
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Joveria Farooqi
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Safina Abdul Razzak
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Nazish Jabeen
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Jason Rao
- Health Security Partners, Washington, DC, 20009, USA
| | - Sadia Shakoor
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Rumina Hasan
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan. .,Department of Infection Biology, Faculty Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
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23
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A Genome-Scale Antibiotic Screen in Serratia marcescens Identifies YdgH as a Conserved Modifier of Cephalosporin and Detergent Susceptibility. Antimicrob Agents Chemother 2021; 65:e0078621. [PMID: 34491801 DOI: 10.1128/aac.00786-21] [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: 11/20/2022] Open
Abstract
Serratia marcescens, a member of the order Enterobacterales, is adept at colonizing health care environments and is an important cause of invasive infections. Antibiotic resistance is a daunting problem in S. marcescens because, in addition to plasmid-mediated mechanisms, most isolates have considerable intrinsic resistance to multiple antibiotic classes. To discover endogenous modifiers of antibiotic susceptibility in S. marcescens, a high-density transposon insertion library was subjected to sub-MICs of two cephalosporins, cefoxitin, and cefepime, as well as the fluoroquinolone ciprofloxacin. Comparisons of transposon insertion abundance before and after antibiotic exposure identified hundreds of potential modifiers of susceptibility to these agents. Using single-gene deletions, we validated several candidate modifiers of cefoxitin susceptibility and chose ydgH, a gene of unknown function, for further characterization. In addition to cefoxitin, deletion of ydgH in S. marcescens resulted in decreased susceptibility to multiple third-generation cephalosporins and, in contrast, to increased susceptibility to both cationic and anionic detergents. YdgH is highly conserved throughout the Enterobacterales, and we observed similar phenotypes in Escherichia coli O157:H7 and Enterobacter cloacae mutants. YdgH is predicted to localize to the periplasm, and we speculate that it may be involved there in cell envelope homeostasis. Collectively, our findings provide insight into chromosomal mediators of antibiotic resistance in S. marcescens and will serve as a resource for further investigations of this important pathogen.
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24
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Scarbrough BA, Eade CR, Reid AJ, Williams TC, Troutman JM. Lipopolysaccharide Is a 4-Aminoarabinose Donor to Exogenous Polyisoprenyl Phosphates through the Reverse Reaction of the Enzyme ArnT. ACS OMEGA 2021; 6:25729-25741. [PMID: 34632229 PMCID: PMC8495848 DOI: 10.1021/acsomega.1c04036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Indexed: 05/11/2023]
Abstract
Modification of the lipid A portion of LPS with cationic monosaccharides provides resistance to polymyxins, which are often employed as a last resort to treat multidrug-resistant bacterial infections. Here, we describe the use of fluorescent polyisoprenoids, liquid chromatography-mass spectrometry, and bacterial genetics to probe the activity of membrane-localized proteins that utilize the 55-carbon lipid carrier bactoprenyl phosphate (BP). We have discovered that a substantial background reaction occurs when B-strain E. coli cell membrane fractions are supplemented with exogenous BP. This reaction involves proteins associated with the arn operon, which is necessary for the covalent modification of lipid A with the cationic 4-aminoarabinose (Ara4N). Using a series of arn operon gene deletion mutants, we identified that the modification was dependent on ArnC, which is responsible for forming BP-linked Ara4N, or ArnT, which transfers Ara4N to lipid A. Surprisingly, we found that the majority of the Ara4N-modified isoprenoid was due to the reverse reaction catalyzed by ArnT and demonstrate this using heat-inactivated membrane fractions, isolated lipopolysaccharide fractions, and analyses of a purified ArnT. This work provides methods that will facilitate thorough and rapid investigation of bacterial outer membrane remodeling and the evaluation of polyisoprenoid precursors required for covalent glycan modifications.
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Affiliation(s)
- Beth A. Scarbrough
- Nanoscale
Science Program, The University of North
Carolina at Charlotte, Charlotte, North Carolina 28223-0001, United States
| | - Colleen R. Eade
- Department
of Chemistry, The University of North Carolina
at Charlotte, Charlotte, North Carolina 28223-0001, United States
| | - Amanda J. Reid
- Nanoscale
Science Program, The University of North
Carolina at Charlotte, Charlotte, North Carolina 28223-0001, United States
| | - Tiffany C. Williams
- Department
of Chemistry, The University of North Carolina
at Charlotte, Charlotte, North Carolina 28223-0001, United States
| | - Jerry M. Troutman
- Department
of Chemistry, The University of North Carolina
at Charlotte, Charlotte, North Carolina 28223-0001, United States
- Nanoscale
Science Program, The University of North
Carolina at Charlotte, Charlotte, North Carolina 28223-0001, United States
- . Phone: 704-687-5180
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25
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Microbiological and Toxicological Hazards in Sewage Treatment Plant Bioaerosol and Dust. Toxins (Basel) 2021; 13:toxins13100691. [PMID: 34678984 PMCID: PMC8540054 DOI: 10.3390/toxins13100691] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 11/17/2022] Open
Abstract
Despite the awareness that work in the sewage treatment plant is associated with biological hazards, they have not been fully recognised so far. The research aims to comprehensively evaluate microbiological and toxicological hazards in the air and settled dust in workstations in a sewage treatment plant. The number of microorganisms in the air and settled dust was determined using the culture method and the diversity was evaluated using high-throughput sequencing. Endotoxin concentration was assessed with GC-MS (gas chromatography-mass spectrometry) while secondary metabolites with LC-MS/MS (liquid chromatography coupled to tandem mass spectrometry). Moreover, cytotoxicity of settled dust against a human lung epithelial lung cell line was determined with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and UHPLC-Q-ToF-UHRMS (ultra-high-performance liquid chromatography-quadrupole time-of-flight ultrahigh-resolution mass spectrometry) analysis was performed to determine the source of cytotoxicity. The total dust concentration in the sewage treatment plant was low and ranged from 0.030 mg m-3 to 0.044 mg m-3. The highest microbiological contamination was observed in sludge thickening building and screenings storage. Three secondary metabolites were detected in the air and sixteen in the settled dust. They were dominated by compounds typical of lichen and plants and Aspergillus, Penicillium and Fusarium genera mould. The settled dust from the sludge thickening building revealed high cytotoxicity to human lung epithelial cells A-549 (IC50 = 6.98 after 72 h). This effect can be attributed to a biocidal compound-didecyldimethylammonium chloride (DDAC-C10) and seven toxic compounds: 4-hydroxynonenal, carbofuran, cerulenin, diethylphosphate, fenpropimorph, naphthalene and onchidal. The presence of DDAC-C10 and other biocidal substances in the sewage treatment plant environment may bring negative results for biological sewage treatment and the natural environment in the future and contribute to microorganisms' increasing antibiotics resistance. Therefore, the concentration of antibiotics, pesticides and disinfectants in sewage treatment plant workstations should be monitored.
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26
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Gogry FA, Siddiqui MT, Sultan I, Haq QMR. Current Update on Intrinsic and Acquired Colistin Resistance Mechanisms in Bacteria. Front Med (Lausanne) 2021; 8:677720. [PMID: 34476235 PMCID: PMC8406936 DOI: 10.3389/fmed.2021.677720] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 07/09/2021] [Indexed: 01/07/2023] Open
Abstract
Colistin regained global interest as a consequence of the rising prevalence of multidrug-resistant Gram-negative Enterobacteriaceae. In parallel, colistin-resistant bacteria emerged in response to the unregulated use of this antibiotic. However, some Gram-negative species are intrinsically resistant to colistin activity, such as Neisseria meningitides, Burkholderia species, and Proteus mirabilis. Most identified colistin resistance usually involves modulation of lipid A that decreases or removes early charge-based interaction with colistin through up-regulation of multistep capsular polysaccharide expression. The membrane modifications occur by the addition of cationic phosphoethanolamine (pEtN) or 4-amino-l-arabinose on lipid A that results in decrease in the negative charge on the bacterial surface. Therefore, electrostatic interaction between polycationic colistin and lipopolysaccharide (LPS) is halted. It has been reported that these modifications on the bacterial surface occur due to overexpression of chromosomally mediated two-component system genes (PmrAB and PhoPQ) and mutation in lipid A biosynthesis genes that result in loss of the ability to produce lipid A and consequently LPS chain, thereafter recently identified variants of plasmid-borne genes (mcr-1 to mcr-10). It was hypothesized that mcr genes derived from intrinsically resistant environmental bacteria that carried chromosomal pmrC gene, a part of the pmrCAB operon, code three proteins viz. pEtN response regulator PmrA, sensor kinase protein PmrAB, and phosphotransferase PmrC. These plasmid-borne mcr genes become a serious concern as they assist in the dissemination of colistin resistance to other pathogenic bacteria. This review presents the progress of multiple strategies of colistin resistance mechanisms in bacteria, mainly focusing on surface changes of the outer membrane LPS structure and other resistance genetic determinants. New handier and versatile methods have been discussed for rapid detection of colistin resistance determinants and the latest approaches to revert colistin resistance that include the use of new drugs, drug combinations and inhibitors. Indeed, more investigations are required to identify the exact role of different colistin resistance determinants that will aid in developing new less toxic and potent drugs to treat bacterial infections. Therefore, colistin resistance should be considered a severe medical issue requiring multisectoral research with proper surveillance and suitable monitoring systems to report the dissemination rate of these resistant genes.
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Affiliation(s)
| | | | - Insha Sultan
- Department of Biosciences, Jamia Millia Islamia, New Delhi, India
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27
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Rodríguez-Santiago J, Cornejo-Juárez P, Silva-Sánchez J, Garza-Ramos U. Polymyxin resistance in Enterobacterales: overview and epidemiology in the Americas. Int J Antimicrob Agents 2021; 58:106426. [PMID: 34419579 DOI: 10.1016/j.ijantimicag.2021.106426] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 08/07/2021] [Accepted: 08/15/2021] [Indexed: 12/30/2022]
Abstract
The worldwide spread of carbapenem- and polymyxin-resistant Enterobacterales represents an urgent public-health threat. However, for most countries in the Americas, the available data are limited, although Latin America has been suggested as a silent spreading reservoir for isolates carrying plasmid-mediated polymyxin resistance mechanisms. This work provides an overall update on polymyxin and polymyxin resistance and focuses on uses, availability and susceptibility testing. Moreover, a comprehensive review of the current polymyxin resistance epidemiology in the Americas is provided. We found that reports in the English and Spanish literature show widespread carbapenemase-producing and colistin-resistant Klebsiella pneumoniae in the Americas determined by the clonal expansion of the pandemic clone ST258 and mgrB-mediated colistin resistance. In addition, widespread IncI2 and IncX4 plasmids carrying mcr-1 in Escherichia coli come mainly from human sources; however, plasmid-mediated colistin resistance in the Americas is underreported in the veterinary sector. These findings demonstrate the urgent need for the implementation of polymyxin resistance surveillance in Enterobacterales as well as appropriate regulatory measures for antimicrobial use in veterinary medicine.
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Affiliation(s)
- J Rodríguez-Santiago
- Instituto Nacional de Salud Pública (INSP), Centro de Investigación sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Cuernavaca, Morelos, México; Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - P Cornejo-Juárez
- Departamento de Infectología, Instituto Nacional de Cancerología (INCan), Ciudad de México, México
| | - J Silva-Sánchez
- Instituto Nacional de Salud Pública (INSP), Centro de Investigación sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Cuernavaca, Morelos, México
| | - U Garza-Ramos
- Instituto Nacional de Salud Pública (INSP), Centro de Investigación sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Cuernavaca, Morelos, México.
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28
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Salam LB, Obayori OS, Ilori MO, Amund OO. Impact of spent engine oil contamination on the antibiotic resistome of a tropical agricultural soil. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:1251-1271. [PMID: 33993436 DOI: 10.1007/s10646-021-02422-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
Profiling of hydrocarbon-contaminated soils for antibiotic resistance genes (ARGs) is becoming increasingly important due to emerging realities of their preponderance in hydrocarbon-inundated matrices. In this study, the antibiotic resistome of an agricultural soil (1S) and agricultural soil contaminated with spent engine oil (AB1) were evaluated via functional annotation of the open reading frames (ORFs) of their metagenomes using the comprehensive antibiotic database (CARD) and KEGG KofamKOALA. CARD analysis of AB1 metagenome revealed the detection of 24 AMR (antimicrobial resistance) gene families, 66 ARGs, and the preponderance (69.7%) of ARGs responsible for antibiotic efflux in AB1 metagenome. CARD analysis of 1S metagenome revealed four AMR gene families and five ARGs. Functional annotation of the two metagenomes using KofamKOALA showed 171 ARGs in AB1 and 29 ARGs in 1S, respectively. Majority of the detected ARGs in AB1 (121; 70.8%) and 1S (16; 55.2%) using KofamKOALA are responsible for antibiotic efflux while ARGs for other resistance mechanisms were also detected. All the five major antibiotic efflux pump systems were detected in AB1 metagenome, though majority of the ARGs for antibiotic efflux belong to the RND (resistance-nodulation-cell division) and MFS (major facilitator superfamily) efflux systems. Significant differences observed in the ARGs recovered from 1S and AB1 metagenomes were statistically validated (P < 0.05). SEO contamination is believed to be responsible for ARGs increase in AB1 metagenome via mechanisms of cross-resistance especially with efflux pumps. The detection of these ARGs is of great public health concern in this era of multidrug resistant isolates resurgence.
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Affiliation(s)
- Lateef Babatunde Salam
- Department of Biological Sciences, Microbiology Unit, Summit University, Offa, Kwara, Nigeria.
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29
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Chin CY, Zhao J, Llewellyn AC, Golovliov I, Sjöstedt A, Zhou P, Weiss DS. Francisella FlmX broadly affects lipopolysaccharide modification and virulence. Cell Rep 2021; 35:109247. [PMID: 34133919 DOI: 10.1016/j.celrep.2021.109247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 01/14/2021] [Accepted: 05/20/2021] [Indexed: 10/21/2022] Open
Abstract
The outer membrane protects Gram-negative bacteria from the host environment. Lipopolysaccharide (LPS), a major outer membrane constituent, has distinct components (lipid A, core, O-antigen) generated by specialized pathways. In this study, we describe the surprising convergence of these pathways through FlmX, an uncharacterized protein in the intracellular pathogen Francisella. FlmX is in the flippase family, which includes proteins that traffic lipid-linked envelope components across membranes. flmX deficiency causes defects in lipid A modification, core remodeling, and O-antigen addition. We find that an F. tularensis mutant lacking flmX is >1,000,000-fold attenuated. Furthermore, FlmX is required to resist the innate antimicrobial LL-37 and the antibiotic polymyxin. Given FlmX's central role in LPS modification and its conservation in intracellular pathogens Brucella, Coxiella, and Legionella, FlmX may represent a novel drug target whose inhibition could cripple bacterial virulence and sensitize bacteria to innate antimicrobials and antibiotics.
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Affiliation(s)
- Chui-Yoke Chin
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30329, USA
| | - Jinshi Zhao
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Anna C Llewellyn
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30329, USA
| | - Igor Golovliov
- Clinical Bacteriology, and Laboratory for Molecular Infection Medicine Sweden, Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden
| | - Anders Sjöstedt
- Clinical Bacteriology, and Laboratory for Molecular Infection Medicine Sweden, Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden
| | - Pei Zhou
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - David S Weiss
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30329, USA; Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA.
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30
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Campos PAD, Fuga B, Ferreira ML, Brígido RTES, Lincopan N, Gontijo-Filho PP, Ribas RM. Genetic Alterations Associated with Polymyxin B Resistance in Nosocomial KPC-2-Producing Klebsiella pneumoniae from Brazil. Microb Drug Resist 2021; 27:1677-1684. [PMID: 34129401 DOI: 10.1089/mdr.2020.0531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The rapid increased multidrug resistance in Klebsiella pneumoniae has led to a renewed interest in polymyxin antibiotics, such as colistin, as antibiotics of last resort, not least in low/middle income countries. We conducted a genomic survey of clinical polymyxin-resistant K. pneumoniae to investigate the genetic alterations in isolates harboring blaKPC-2. Whole-genome sequencing was performed using an Illumina NextSeq 500 paired-end reads. Mutations and insertion sequence detection were analyzed to seven isolates recovered from clinical specimens of patients hospitalized in Brazil, focusing on key genes associated with polymyxin resistance. Furthermore, the levels of mRNA expression of genes associated with resistance to polymyxin B and other antimicrobials were evaluated by quantitative real-time PCR. Eighty-five percent of the isolates were assigned to clonal complex 258, with a minimum inhibitory concentration range of 4 to >256 mg/L for polymyxin B. It was possible to observe the presence of one important insertion element, ISKpn13, in a strain recovered from the blood that have blaKPC-2. Deleterious mutations reported in PmrB (R256G), YciM (N212T), and AcrB (T598A) were common, and mobile colistin resistance (mcr) genes were absent in all the isolates. RT-qPCR analysis revealed an overexpression of the pmrC (1.160-fold), pmrD (2.258-fold), and kpnE (1.530-fold) genes in the polymyxin B-resistant isolates compared with the expression of the polymyxin B-susceptible K. pneumoniae isolate. Overall, these results demonstrate the diversity of genetic variations in polymyxin-resistant populations derived from the different clonal strains, but the same sequence types, and suggest that there are still unknown mechanisms of polymyxin resistance in K. pneumoniae.
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Affiliation(s)
- Paola Amaral de Campos
- Laboratório de Microbiologia Molecular, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Bruna Fuga
- Laboratório de Microbiologia Molecular, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil.,Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil
| | - Melina Lorraine Ferreira
- Laboratório de Microbiologia Molecular, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | | | - Nilton Lincopan
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil
| | - Paulo P Gontijo-Filho
- Laboratório de Microbiologia Molecular, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Rosineide Marques Ribas
- Laboratório de Microbiologia Molecular, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
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Moyer TB, Purvis AL, Wommack AJ, Hicks LM. Proteomic response of Escherichia coli to a membrane lytic and iron chelating truncated Amaranthus tricolor defensin. BMC Microbiol 2021; 21:110. [PMID: 33845758 PMCID: PMC8042948 DOI: 10.1186/s12866-021-02176-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 03/31/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. RESULTS Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. CONCLUSIONS This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.
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Affiliation(s)
- Tessa B Moyer
- Department of Chemistry, University of North Carolina at Chapel Hill, 125 South Rd. CB#3290, Chapel Hill, NC, 27599, USA
| | | | - Andrew J Wommack
- Department of Chemistry, High Point University, High Point, NC, USA
| | - Leslie M Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, 125 South Rd. CB#3290, Chapel Hill, NC, 27599, USA.
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Abstract
Antibiotic resistance is a major global health challenge and, worryingly, several key Gram negative pathogens can become resistant to most currently available antibiotics. Polymyxins have been revived as a last-line therapeutic option for the treatment of infections caused by multidrug-resistant Gram negative bacteria, in particular Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacterales. Polymyxins were first discovered in the late 1940s but were abandoned soon after their approval in the late 1950s as a result of toxicities (e.g., nephrotoxicity) and the availability of "safer" antibiotics approved at that time. Therefore, knowledge on polymyxins had been scarce until recently, when enormous efforts have been made by several research teams around the world to elucidate the chemical, microbiological, pharmacokinetic/pharmacodynamic, and toxicological properties of polymyxins. One of the major achievements is the development of the first scientifically based dosage regimens for colistin that are crucial to ensure its safe and effective use in patients. Although the guideline has not been developed for polymyxin B, a large clinical trial is currently being conducted to optimize its clinical use. Importantly, several novel, safer polymyxin-like lipopeptides are developed to overcome the nephrotoxicity, poor efficacy against pulmonary infections, and narrow therapeutic windows of the currently used polymyxin B and colistin. This review discusses the latest achievements on polymyxins and highlights the major challenges ahead in optimizing their clinical use and discovering new-generation polymyxins. To save lives from the deadly infections caused by Gram negative "superbugs," every effort must be made to improve the clinical utility of the last-line polymyxins. SIGNIFICANCE STATEMENT: Antimicrobial resistance poses a significant threat to global health. The increasing prevalence of multidrug-resistant (MDR) bacterial infections has been highlighted by leading global health organizations and authorities. Polymyxins are a last-line defense against difficult-to-treat MDR Gram negative pathogens. Unfortunately, the pharmacological information on polymyxins was very limited until recently. This review provides a comprehensive overview on the major achievements and challenges in polymyxin pharmacology and clinical use and how the recent findings have been employed to improve clinical practice worldwide.
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Affiliation(s)
- Sue C Nang
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Mohammad A K Azad
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Tony Velkov
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Qi Tony Zhou
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Jian Li
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
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Guest RL, Rutherford ST, Silhavy TJ. Border Control: Regulating LPS Biogenesis. Trends Microbiol 2021; 29:334-345. [PMID: 33036869 PMCID: PMC7969359 DOI: 10.1016/j.tim.2020.09.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 12/20/2022]
Abstract
The outer membrane (OM) is a defining feature of Gram-negative bacteria that serves as a permeability barrier and provides rigidity to the cell. Critical to OM function is establishing and maintaining an asymmetrical bilayer structure with phospholipids in the inner leaflet and the complex glycolipid lipopolysaccharide (LPS) in the outer leaflet. Cells ensure this asymmetry by regulating the biogenesis of lipid A, the conserved and essential anchor of LPS. Here we review the consequences of disrupting the regulatory components that control lipid A biogenesis, focusing on the rate-limiting step performed by LpxC. Dissection of these processes provides critical insights into bacterial physiology and potential new targets for antibiotics able to overcome rapidly spreading resistance mechanisms.
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Affiliation(s)
- Randi L Guest
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Steven T Rutherford
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA, USA
| | - Thomas J Silhavy
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
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34
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Gadishaw-Lue C, Banaag A, Birstonas S, Francis AS, Barnett Foster D. Bile Salts Differentially Enhance Resistance of Enterohemorrhagic Escherichia coli O157:H7 to Host Defense Peptides. Infect Immun 2021; 89:e00719-20. [PMID: 33229368 PMCID: PMC7822141 DOI: 10.1128/iai.00719-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 11/13/2020] [Indexed: 12/28/2022] Open
Abstract
During passage through the human gastrointestinal tract, enterohemorrhagic Escherichia coli (EHEC) is exposed to membrane-damaging bile in the small intestine. We previously reported that EHEC treatment with a physiological bile salt mixture upregulates basRS, encoding a two-component system, and arnBCADTEF, encoding the aminoarabinose lipid A modification pathway (J. V. Kus, A. Gebremedhin, V. Dang, S. L. Tran, A. Serbanescu, and D. Barnett Foster, J Bacteriol 193: 4509-4515, 2011, https://doi.org/10.1128/JB.00200-11). The present study examined the effect of bile salt mix (BSM) treatment on EHEC resistance to three human gastrointestinal defense peptides-HD-5, HNP-1, and LL-37-as well as the role of basRS and arnT in the respective responses. After BSM treatment, EHEC resistance to HD-5 and HNP-1 was significantly increased in a BSM-, defensin dose-dependent manner. The resistance phenotype was dependent on both basRS and arnT However, the BSM treatment did not alter EHEC resistance to LL-37, even when the ompT gene, encoding an LL-37 cleavage protease, was disrupted. Interestingly, enteropathogenic E. coli, a related pathogen that infects the small intestine, showed a similar BSM-induced resistance phenotype. Using a model of EHEC infection in Galleria mellonella, we found significantly lower survival rates in wax moth larvae infected with BSM-treated wild-type EHEC than in those infected with a BSM-treated basS mutant, suggesting that treatment with a physiological BSM enhances virulence through a basS-mediated pathway. The results of this investigation provide persuasive evidence that bile salts typically encountered during transit through the small intestine can serve as an environmental cue for EHEC, enhancing resistance to several key host defense peptides.
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Affiliation(s)
- Crystal Gadishaw-Lue
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Alyssa Banaag
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Sarah Birstonas
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Aju-Sue Francis
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Debora Barnett Foster
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
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35
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Panta PR, Doerrler WT. A Burkholderia thailandensis DedA Family Membrane Protein Is Required for Proton Motive Force Dependent Lipid A Modification. Front Microbiol 2021; 11:618389. [PMID: 33510730 PMCID: PMC7835334 DOI: 10.3389/fmicb.2020.618389] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/17/2020] [Indexed: 12/18/2022] Open
Abstract
The DedA family is a conserved membrane protein family found in most organisms. A Burkholderia thailandensis DedA family protein, named DbcA, is required for high-level colistin (polymyxin E) resistance, but the mechanism awaits elucidation. Modification of lipopolysaccharide lipid A with the cationic sugar aminoarabinose (Ara4N) is required for colistin resistance and is dependent upon protonmotive force (PMF) dependent transporters. B. thailandensis ΔdbcA lipid A contains only small amounts of Ara4N, likely leading to colistin sensitivity. Two B. thailandensis operons are required for lipid A modification with Ara4N, one needed for biosynthesis of undecaprenyl-P-Ara4N and one for transport of the lipid linked sugar and subsequent lipid A modification. Here, we directed overexpression of each arn operon by genomic insertion of inducible promoters. We found that overexpression of arn operons in ΔdbcA can partially, but not completely, restore Ara4N modification of lipid A and colistin resistance. Artificially increasing the PMF by lowering the pH of the growth media also increased membrane potential, amounts of Ara4N, and colistin resistance of ΔdbcA. In addition, the products of arn operons are essential for acid tolerance, suggesting a physiological function of Ara4N modification. Finally, we show that ΔdbcA is sensitive to bacitracin and expression of a B. thailandensis UppP/BacA homolog (BTH_I1512) can partially restore resistance to bacitracin. Expression of a different UppP/BacA homolog (BTH_I2750) can partially restore colistin resistance, without changing the lipid A profile. This work suggests that maintaining optimal membrane potential at slightly alkaline pH media by DbcA is responsible for proper modification of lipid A by Ara4N and provides evidence of lipid A modification-dependent and -independent mechanisms of colistin resistance in B. thailandensis.
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Affiliation(s)
- Pradip R Panta
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - William T Doerrler
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
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36
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Kunwar CB, Birstonas S, McPhee JB, Barnett Foster D. Molecular basis of bile-salt- and iron-induced enterohaemorrhagic E. coli resistance to cationic antimicrobial peptides. MICROBIOLOGY-SGM 2020; 166:1149-1159. [PMID: 33205745 DOI: 10.1099/mic.0.000988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Colonization of the gastrointestinal tract by enterohaemorrhagic Escherichia coli (EHEC) is critically dependent on its ability to sense and respond to various microenvironments within the host. EHEC exposure to physiologically relevant levels of bile salts upregulates the two-component system, pmrAB, and the arnBCADTEF operon, resulting in lipopolysaccharide modification and increased resistance to the cationic antimicrobial peptide, polymyxin B (PMB). A similar pmrAB- and arn-dependent PMB resistance has been observed in Salmonella enterica in the presence of ferric iron. Limiting magnesium levels and mild acid can also induce Salmonella resistance to PMB through another two-component system, PhoPQ and the connector protein, PmrD. This study aims to evaluate the relative contributions of a bile-salt mix (BSM), iron, limiting magnesium as well as the roles of pmrAB, phoPQ and pmrD to EHEC's resistance to PMB. Killing assays show that EHEC treatment with the BSM or iron under excess magnesium and neutral pH conditions induces a pmrAB-dependent, phoP-independent PMB resistance. By contrast, exposure to limiting magnesium triggers a pmrB-, phoP- and pmrD-dependent PMB resistance. The iron-induced PMB resistance is independent of phoP and pmrD under limiting magnesium conditions while the bile-salt-induced PMB resistance is independent of pmrD only under non-PhoP-inducing conditions. GFP-pmrD transcriptional reporter studies reveal that the limiting magnesium enhances pmrD expression, which is repressed upon additional exposure to either BSM or iron. Our results also show that exposure to mild acid enhances PMB resistance in a pmrD-independent manner and GFP reporter results confirm minimal expression of pmrD at this pH regardless of the magnesium level. This study provides novel insights into how EHEC differentially employs PmrAB, PhoPQ and PmrD to monitor and respond to bile salts, iron, acidic pH and magnesium typically encountered within the gastrointestinal tract in order to modulate its survival against cationic antimicrobial peptides.
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Affiliation(s)
- Chhatra B Kunwar
- Department of Chemistry & Biology, Ryerson University, Toronto, ON, Canada
| | - Sarah Birstonas
- Department of Chemistry & Biology, Ryerson University, Toronto, ON, Canada
| | - Joseph B McPhee
- Department of Chemistry & Biology, Ryerson University, Toronto, ON, Canada
| | - Debora Barnett Foster
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.,Department of Chemistry & Biology, Ryerson University, Toronto, ON, Canada
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The Efflux Pump MexXY/OprM Contributes to the Tolerance and Acquired Resistance of Pseudomonas aeruginosa to Colistin. Antimicrob Agents Chemother 2020; 64:AAC.02033-19. [PMID: 31964794 DOI: 10.1128/aac.02033-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 01/13/2020] [Indexed: 12/29/2022] Open
Abstract
The intrinsic resistance of Pseudomonas aeruginosa to polymyxins in part relies on the addition of 4-amino-4-deoxy-l-arabinose (Ara4N) molecules to the lipid A of lipopolysaccharide (LPS), through induction of operon arnBCADTEF-ugd (arn) expression. As demonstrated previously, at least three two-component regulatory systems (PmrAB, ParRS, and CprRS) are able to upregulate this operon when bacteria are exposed to colistin. In the present study, gene deletion experiments with the bioluminescent strain PAO1::lux showed that ParRS is a key element in the tolerance of P. aeruginosa to this last-resort antibiotic (i.e., resistance to early drug killing). Other loci of the ParR regulon, such as those encoding the efflux proteins MexXY (mexXY), the polyamine biosynthetic pathway PA4773-PA4774-PA4775, and Ara4N LPS modification process (arnBCADTEF-ugd), also contribute to the bacterial tolerance in an intricate way with ParRS. Furthermore, we found that both stable upregulation of the arn operon and drug-induced ParRS-dependent overexpression of the mexXY genes accounted for the elevated resistance of pmrB mutants to colistin. Deletion of the mexXY genes in a constitutively activated ParR mutant of PAO1 was associated with significantly increased expression of the genes arnA, PA4773, and pmrA in the absence of colistin exposure, thereby highlighting a functional link between the MexXY/OprM pump, the PA4773-PA4774-PA4775 pathway, and Ara4N-based modification of LPS. The role played by MexXY/OprM in the adaptation of P. aeruginosa to polymyxins opens new perspectives for restoring the susceptibility of resistant mutants through the use of efflux inhibitors.
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38
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Ranjith K, SaiAbhilash CR, Sai Prashanthi G, Padakandla SR, Sharma S, Shivaji S. Phylogenetic Grouping of Human Ocular Escherichia coli Based on Whole-Genome Sequence Analysis. Microorganisms 2020; 8:microorganisms8030422. [PMID: 32192112 PMCID: PMC7143957 DOI: 10.3390/microorganisms8030422] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/10/2020] [Accepted: 03/14/2020] [Indexed: 01/12/2023] Open
Abstract
Escherichia coli is a predominant bacterium in the intestinal tracts of animals. Phylogenetically, strains have been classified into seven phylogroups, A, B1, B2, C, D, E, and F. Pathogenic strains have been categorized into several pathotypes such as Enteropathogenic (EPEC), Enterotoxigenic (ETEC), Enteroinvasive (EIEC), Enteroaggregative (EAEC), Diffusely adherent (DAEC), Uropathogenic (UPEC), Shiga-toxin producing (STEC) or Enterohemorrhagic (EHEC) and Extra-intestinal pathogenic E. coli (ExPEC). E. coli also survives as a commensal on the ocular surface. However, under conditions of trauma and immune-compromised states, E. coli causes conjunctivitis, keratitis, endopthalmitis, dacyrocystitis, etc. The phylogenetic affiliation and the pathotype status of these ocular E. coli strains is not known. For this purpose, the whole-genome sequencing of the 10 ocular E. coli strains was accomplished. Based on whole-genome SNP variation, the ocular E. coli strains were assigned to phylogenetic groups A (two isolates), B2 (seven isolates), and C (one isolate). Furthermore, results indicated that ocular E. coli originated either from feces (enteropathogenic and enterotoxigenic), urine (uropathogenic), or from extra-intestinal sources (extra-intestinal pathogenic). A high concordance was observed between the presence of AMR (Antimicrobial Resistance) genes and antibiotic resistance in the ocular E. coli strains. Furthermore, several virulent genes (fimB to fimI, papB to papX, etc.) and prophages (Enterobacteria phage HK97, Enterobacteria phage P1, Escherichia phage D108 etc.) were unique to ocular E. coli. This is the first report on a whole-genome analysis of ocular E. coli strains.
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39
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Rismondo J, Haddad TFM, Shen Y, Loessner MJ, Gründling A. GtcA is required for LTA glycosylation in Listeria monocytogenes serovar 1/2a and Bacillus subtilis. ACTA ACUST UNITED AC 2020; 6:100038. [PMID: 32743150 PMCID: PMC7389260 DOI: 10.1016/j.tcsw.2020.100038] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/16/2020] [Accepted: 02/11/2020] [Indexed: 11/26/2022]
Abstract
The cell wall polymers wall teichoic acid (WTA) and lipoteichoic acid (LTA) are often modified with glycosyl and D-alanine residues. Recent studies have shown that a three-component glycosylation system is used for the modification of LTA in several Gram-positive bacteria including Bacillus subtilis and Listeria monocytogenes. In the L. monocytogenes 1/2a strain 10403S, the cytoplasmic glycosyltransferase GtlA is thought to use UDP-galactose to produce the C55-P-galactose lipid intermediate, which is transported across the membrane by an unknown flippase. Next, the galactose residue is transferred onto the LTA backbone on the outside of the cell by the glycosyltransferase GtlB. Here we show that GtcA is necessary for the glycosylation of LTA in L. monocytogenes 10403S and B. subtilis 168 and we hypothesize that these proteins act as C55-P-sugar flippases. With this we revealed that GtcA is involved in the glycosylation of both teichoic acid polymers in L. monocytogenes 10403S, namely WTA with N-acetylglucosamine and LTA with galactose residues. These findings indicate that the L. monocytogenes GtcA protein can act on different C55-P-sugar intermediates. Further characterization of GtcA in L. monocytogenes led to the identification of residues essential for its overall function as well as residues, which predominately impact WTA or LTA glycosylation.
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Affiliation(s)
- Jeanine Rismondo
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Talal F M Haddad
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Yang Shen
- Institute of Food, Nutrition and Health, ETH Zurich, 8092 Zurich, Switzerland
| | - Martin J Loessner
- Institute of Food, Nutrition and Health, ETH Zurich, 8092 Zurich, Switzerland
| | - Angelika Gründling
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
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40
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Bencivenga-Barry NA, Lim B, Herrera CM, Trent MS, Goodman AL. Genetic Manipulation of Wild Human Gut Bacteroides. J Bacteriol 2020; 202:e00544-19. [PMID: 31712278 PMCID: PMC6964735 DOI: 10.1128/jb.00544-19] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/01/2019] [Indexed: 12/30/2022] Open
Abstract
Bacteroides is one of the most prominent genera in the human gut microbiome, and study of this bacterial group provides insights into gut microbial ecology and pathogenesis. In this report, we introduce a negative selection system for rapid and efficient allelic exchange in wild Bacteroides species that does not require any alterations to the genetic background or a nutritionally defined culture medium. In this approach, dual antibacterial effectors normally delivered via type VI secretion are targeted to the bacterial periplasm under the control of tightly regulated anhydrotetracycline (aTC)-inducible promoters. Introduction of aTC selects for recombination events producing the desired genetic modification, and the dual effector design allows for broad applicability across strains that may have immunity to one counterselection effector. We demonstrate the utility of this approach across 21 human gut Bacteroides isolates representing diverse species, including strains isolated directly from human donors. We use this system to establish that antimicrobial peptide resistance in Bacteroides vulgatus is determined by the product of a gene that is not included in the genomes of previously genetically tractable members of the human gut microbiome.IMPORTANCE Human gut Bacteroides species exhibit strain-level differences in their physiology, ecology, and impact on human health and disease. However, existing approaches for genetic manipulation generally require construction of genetically modified parental strains for each microbe of interest or defined medium formulations. In this report, we introduce a robust and efficient strategy for targeted genetic manipulation of diverse wild-type Bacteroides species from the human gut. This system enables genetic investigation of members of human and animal microbiomes beyond existing model organisms.
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Affiliation(s)
- Natasha A Bencivenga-Barry
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
| | - Bentley Lim
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
| | - Carmen M Herrera
- Department of Infectious Diseases, University of Georgia at Athens, College of Veterinary Medicine, Athens, Georgia, USA
- Center for Vaccines and Immunology, University of Georgia at Athens, College of Veterinary Medicine, Athens, Georgia, USA
| | - M Stephen Trent
- Department of Infectious Diseases, University of Georgia at Athens, College of Veterinary Medicine, Athens, Georgia, USA
- Center for Vaccines and Immunology, University of Georgia at Athens, College of Veterinary Medicine, Athens, Georgia, USA
- Department of Microbiology, University of Georgia at Athens, College of Arts and Sciences, Athens, Georgia, USA
| | - Andrew L Goodman
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
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Yu L, Zhang J, Fu Y, Zhao Y, Wang Y, Zhao J, Guo Y, Li C, Zhang X. Synergetic Effects of Combined Treatment of Colistin With Meropenem or Amikacin on Carbapenem-Resistant Klebsiella pneumoniae in vitro. Front Cell Infect Microbiol 2019; 9:422. [PMID: 31921701 PMCID: PMC6916149 DOI: 10.3389/fcimb.2019.00422] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/28/2019] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to investigate the synergistic and bactericidal effects of combinations of colistin with meropenem or amikacin in vitro and provide laboratory data needed for development of therapeutic strategies for the treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection. We found that minimum inhibitory concentration (MIC) of colistin, meropenem and amikacin were 2~32, 4~256, and 1~16384 μg/ml, respectively. The minimum bactericidal concentration of the antibiotics was either 1× or 2×MIC. Treatments of 6 CRKP isolates at 1 μg/ml colistin completely killed 2 of them and suppressed 4 others growth. 4 CRKP isolates at 16 μg/ml meropenem or amikacin completely killed and suppressed 2 others growth. 2 CRKP isolates showed synergic effects in all colistin combination and 3 CRKP isolates showed synergic effects in part of colistin combination. Our data suggest that colistin in combination with either meropenem or amikacin could be a valid therapeutic option against colistin-resistant CRKP isolates. Moreover, the combination of colistin-amikacin is less expensive to treat CRKP infections in Eastern Heilongjiang Province.
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Affiliation(s)
- Lan Yu
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Jisheng Zhang
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yanjun Fu
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yongxin Zhao
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yong Wang
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Jing Zhao
- Department of Scientific Research Section, Jiamusi University School of Clinical Medicine, Jiamusi, China
| | - Yuhang Guo
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Chunjiang Li
- Department of Pathogenic Biology, Jiamusi University School of Basic Medicine, Jiamusi, China
| | - Xiaoli Zhang
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
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42
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Panta PR, Kumar S, Stafford CF, Billiot CE, Douglass MV, Herrera CM, Trent MS, Doerrler WT. A DedA Family Membrane Protein Is Required for Burkholderia thailandensis Colistin Resistance. Front Microbiol 2019; 10:2532. [PMID: 31827463 PMCID: PMC6849406 DOI: 10.3389/fmicb.2019.02532] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/21/2019] [Indexed: 12/15/2022] Open
Abstract
Colistin is a “last resort” antibiotic for treatment of infections caused by some multidrug resistant Gram-negative bacterial pathogens. Resistance to colistin varies between bacterial species. Some Gram-negative bacteria such as Burkholderia spp. are intrinsically resistant to very high levels of colistin with minimal inhibitory concentrations (MIC) often above 0.5 mg/ml. We have previously shown DedA family proteins YqjA and YghB are conserved membrane transporters required for alkaline tolerance and resistance to several classes of dyes and antibiotics in Escherichia coli. Here, we show that a DedA family protein in Burkholderia thailandensis (DbcA; DedA of Burkholderia required for colistin resistance) is a membrane transporter required for resistance to colistin. Mutation of dbcA results in >100-fold greater sensitivity to colistin. Colistin resistance is often conferred via covalent modification of lipopolysaccharide (LPS) lipid A. Mass spectrometry of lipid A of ΔdbcA showed a sharp reduction of aminoarabinose in lipid A compared to wild type. Complementation of colistin sensitivity of B. thailandensis ΔdbcA was observed by expression of dbcA, E. coli yghB or E. coli yqjA. Many proton-dependent transporters possess charged amino acids in transmembrane domains that take part in the transport mechanism and are essential for function. Site directed mutagenesis of conserved and predicted membrane embedded charged amino acids suggest that DbcA functions as a proton-dependent transporter. Direct measurement of membrane potential shows that B. thailandensis ΔdbcA is partially depolarized suggesting that loss of protonmotive force can lead to alterations in LPS structure and severe colistin sensitivity in this species.
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Affiliation(s)
- Pradip R Panta
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Sujeet Kumar
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Caroline F Stafford
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Caitlin E Billiot
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Martin V Douglass
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, United States.,Center for Vaccines and Immunology, University of Georgia College of Veterinary Medicine, Athens, GA, United States
| | - Carmen M Herrera
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, United States.,Center for Vaccines and Immunology, University of Georgia College of Veterinary Medicine, Athens, GA, United States
| | - M Stephen Trent
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, United States.,Center for Vaccines and Immunology, University of Georgia College of Veterinary Medicine, Athens, GA, United States
| | - William T Doerrler
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
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43
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Kim S, Woo JH, Kim N, Kim MH, Kim SY, Son JH, Moon DC, Lim SK, Shin M, Lee JC. Characterization Of Chromosome-Mediated Colistin Resistance In Escherichia coli Isolates From Livestock In Korea. Infect Drug Resist 2019; 12:3291-3299. [PMID: 31695448 PMCID: PMC6815941 DOI: 10.2147/idr.s225383] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/25/2019] [Indexed: 02/06/2023] Open
Abstract
Purpose Colistin resistance in gram-negative bacteria from humans and livestock has been increasingly reported worldwide. The aim of this study was to investigate the underlying mechanisms of chromosome-mediated colistin resistance in Escherichia coli isolates from livestock in Korea. Materials and methods Thirty mcr-1-negative isolates were selected from a collection of colistin-resistant E. coli isolates collected from livestock in 2005 and 2015 in Korea. Amino acid alterations in PmrAB, PhoPQ, MgrB, and PmrD were investigated. Colistin-resistant derivatives were produced by serial passage of colistin-susceptible E. coli isolates in colistin-containing media. Results Thirty colistin-resistant mcr-negative E. coli isolates were classified into 26 sequence types. Twenty-two isolates carried diverse amino acid alterations in PmrB, PhoP, PhoQ, MgrB, and/or PmrD, whereas no mutation in any of these genes was found in the remaining eight isolates. Sixteen out of the 22 isolates shared a total of nine polymorphic positions that were found in colistin-susceptible E. coli strains. Colistin-resistant derivatives from two colistin-susceptible isolates showed the same genetic alterations that were observed in colistin-resistant clinical isolates. Conclusion Our results suggest that the mechanism underlying chromosome-mediated colistin resistance remain to be discovered in E. coli. Selective pressure of colistin in vitro induced the same genetic mutations associated with colistin resistance in vivo. Efforts to reduce colistin consumption in livestock should be redoubled, to prevent the occurrence of colistin-resistant E. coli strains.
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Affiliation(s)
- Shukho Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Jung Hwa Woo
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Nayeong Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Mi Hyun Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Se Yeon Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Joo Hee Son
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Dong Chan Moon
- Bacterial Disease Division, Animal and Plant Quarantine Agency, Gimcheon-si, Gyeongsangbuk-do, Republic of Korea
| | - Suk-Kyung Lim
- Bacterial Disease Division, Animal and Plant Quarantine Agency, Gimcheon-si, Gyeongsangbuk-do, Republic of Korea
| | - Minsang Shin
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Je Chul Lee
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
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44
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Ligowska-Marzęta M, Hancock V, Ingmer H, M Aarestrup F. Comparison of Gene Expression Profiles of Uropathogenic Escherichia Coli CFT073 after Prolonged Exposure to Subinhibitory Concentrations of Different Biocides. Antibiotics (Basel) 2019; 8:antibiotics8040167. [PMID: 31569631 PMCID: PMC6963283 DOI: 10.3390/antibiotics8040167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/19/2019] [Accepted: 09/23/2019] [Indexed: 01/24/2023] Open
Abstract
Biocides are chemical compounds widely used for sterilization and disinfection. The aim of this study was to examine whether exposure to subinhibitory biocide concentrations influenced transcriptional expression of genes that could improve a pathogen’s drug resistance or fitness. We used DNA microarrays to investigate the transcriptome of the uropathogenic Escherichia coli strain CFT073 in response to prolonged exposure to subinhibitory concentrations of four biocides: benzalkonium chloride, chlorhexidine, hydrogen peroxide and triclosan. Transcription of a gene involved in polymyxin resistance, arnT, was increased after treatment with benzalkonium chloride. However, pretreatment of the bacteria with this biocide did not result in cross-resistance to polymyxin in vitro. Genes encoding products related to transport formed the functional group that was most affected by biocides, as 110 out of 884 genes in this category displayed altered transcription. Transcripts of genes involved in cysteine uptake, sulfate assimilation, dipeptide transport, as well as cryptic phage genes were also more abundant in response to several biocides. Additionally, we identified groups of genes with transcription changes unique to single biocides that might include potential targets for the biocides. The biocides did not increase the resistance potential of the pathogen to other antimicrobials.
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Affiliation(s)
- Małgorzata Ligowska-Marzęta
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, 2300 Copenhagen, Denmark.
- Research Group for Genomic Epidemiology, National Food Institute, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Viktoria Hancock
- Renal Research & Innovation, Baxter International Inc., SE-220 10 Lund, Sweden.
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark.
| | - Frank M Aarestrup
- Research Group for Genomic Epidemiology, National Food Institute, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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45
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Cheng YH, Lin TL, Lin YT, Wang JT. A putative RND-type efflux pump, H239_3064, contributes to colistin resistance through CrrB in Klebsiella pneumoniae. J Antimicrob Chemother 2019; 73:1509-1516. [PMID: 29506266 PMCID: PMC5961088 DOI: 10.1093/jac/dky054] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 01/27/2018] [Indexed: 12/20/2022] Open
Abstract
Background Colistin is one of the last-resort antibiotics used to treat carbapenem-resistant Klebsiella pneumoniae infection. Our previous studies indicated that clinical strains encoding CrrB with amino acid substitutions exhibited higher colistin resistance (MICs ≥512 mg/L) than did colistin-resistant strains encoding mutant MgrB, PmrB or PhoQ. Objectives CrrAB may regulate another unknown mechanism(s) contributing to colistin resistance, besides modifications of LPS with 4-amino-4-deoxy-l-arabinose and phosphoethanolamine. Methods To identify these potential unknown mechanism(s), a transposon mutant library of A4528 crrB(N141I) was constructed. Loci that might contribute to colistin resistance and were regulated by crrB were confirmed by deletion and complementation experiments. Results Screening of 2976 transposon mutants identified 47 mutants in which the MICs of colistin were significantly decreased compared with that for the parent. Besides crrAB, crrC and pmrHFIJKLM operons, these 47 transposon insertion mutants included another 13 loci. Notably, transcript levels of one of these insertion targets, H239_3064 (encoding a putative RND-type efflux pump), were significantly increased in A4528 crrB(N141I) compared with the A4528 parent strain. Deletion of H239_3064 in the A4528 crrB(N141I) background resulted in an 8-fold decrease in the MIC of colistin; complementation of the deletion mutant with H239_3064 restored resistance to colistin. Susceptibilities of A4528-derived strains to other antibiotics were also tested. Mutations of crrB resulted in decreased susceptibility to tetracycline and tigecycline, and deletion of H239_3064 in A4528 crrB(N141I) attenuated this phenomenon. Conclusions This study demonstrated that missense mutations of K. pneumoniae crrB lead to increased expression of H239_3064, leading in turn to decreased susceptibility to colistin, tetracycline and tigecycline.
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Affiliation(s)
- Yi-Hsiang Cheng
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Tzu-Lung Lin
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yi-Tsung Lin
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Emergency and Critical Care Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Jin-Town Wang
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
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46
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Cathelicidin Peptides Restrict Bacterial Growth via Membrane Perturbation and Induction of Reactive Oxygen Species. mBio 2019; 10:mBio.02021-19. [PMID: 31506312 PMCID: PMC6737244 DOI: 10.1128/mbio.02021-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Antimicrobial peptides (AMPs) are an important part of the mammalian innate immune system in the battle against microbial infection. How AMPs function to control bacteria is not clear, as nearly all activity studies use nonphysiological levels of AMPs. We monitored peptide action in live bacterial cells over short time frames with single-cell resolution and found that the primary effect of cathelicidin peptides is to increase the production of oxidative molecules that cause cellular damage in Gram-positive and Gram-negative bacteria. All metazoans produce antimicrobial peptides (AMPs) that have both broad antimicrobial and immunomodulatory activity. Cathelicidins are AMPs that preferentially kill Gram-negative bacteria in vitro, purportedly by assembling into higher-order structures that perforate the membrane. We utilized high-resolution, single-cell fluorescence microscopy to examine their mechanism of action in real time. Engineered cathelicidins rapidly bound to Gram-negative and Gram-positive cells and penetrated the cytoplasmic membrane. Rapid failure of the peptidoglycan superstructure in regions of active turnover caused leakage of cytoplasmic contents and the formation of membrane-bound blebs. A mutation anticipated to destabilize interactions between cathelicidin subunits had no effect on bactericidal activity, suggesting that cathelicidins have activities beyond perforating the membrane. Nanomolar concentrations of cathelicidins, although not bactericidal, reduced the growth rate of Gram-negative and Gram-positive bacteria. The cells exhibited expression changes in multiple essential processes, including protein synthesis, peptidoglycan biosynthesis, respiration, and the detoxification of reactive oxygen species (ROS). Time-lapse imaging revealed that ROS accumulation preceded bleb formation, and treatments that reduced cellular ROS levels overcame these bactericidal effects. We propose that that the primary effect of cathelicidins is to induce the production of ROS that damage bacterial molecules, leading to slowed growth or cell death. Given their low circulating levels in vivo, AMPs may serve to slow bacterial population expansion so that cellular immunity systems can respond to and battle the infection.
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47
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Li Z, Cao Y, Yi L, Liu JH, Yang Q. Emergent Polymyxin Resistance: End of an Era? Open Forum Infect Dis 2019; 6:5550895. [PMID: 31420655 PMCID: PMC6767968 DOI: 10.1093/ofid/ofz368] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Indexed: 12/03/2022] Open
Abstract
Until recently, the polymyxin antibiotics were used sparingly due to dose limiting toxicities. However, the lack of therapeutic alternatives for infections caused by highly resistant Gram-negative bacteria has led to the increased use of the polymyxins. Unfortunately, the world has witnessed increased rates of polymyxin resistance in the last decade, which is likely in part due to its irrational use in human and veterinary medicine. The spread of polymyxin resistance has been aided by the dissemination of the transferable polymyxin-resistance gene, mcr, in humans and the environment. The mortality of colistin-resistant bacteria (CoRB) infections varies in different reports. However, poor clinical outcome was associated with prior colistin treatment, illness severity, complications, and multidrug resistance. Detection of polymyxin resistance in the clinic is possible through multiple robust and practical tests, including broth microdilution susceptibility testing, chromogenic agar testing, and molecular biology assays. There are multiple risk factors that increase a person’s risk for infection with a polymyxin-resistant bacteria, including age, prior colistin treatment, hospitalization, and ventilator support. For patients that are determined to be infected by polymyxin-resistant bacteria, various antibiotic treatment options currently exist. The rising trend of polymyxin resistance threatens patient care and warrants effective control.
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Affiliation(s)
- Zekun Li
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China.,Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Yuping Cao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Lingxian Yi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jian-Hua Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Qiwen Yang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
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48
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Intermembrane transport: Glycerophospholipid homeostasis of the Gram-negative cell envelope. Proc Natl Acad Sci U S A 2019; 116:17147-17155. [PMID: 31420510 PMCID: PMC6717313 DOI: 10.1073/pnas.1902026116] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This perspective addresses recent advances in lipid transport across the Gram-negative inner and outer membranes. While we include a summary of previously existing literature regarding this topic, we focus on the maintenance of lipid asymmetry (Mla) pathway. Discovered in 2009 by the Silhavy group [J. C. Malinverni, T. J. Silhavy, Proc. Natl. Acad. Sci. U.S.A. 106, 8009–8014 (2009)], Mla has become increasingly appreciated for its role in bacterial cell envelope physiology. Through the work of many, we have gained an increasingly mechanistic understanding of the function of Mla via genetic, biochemical, and structural methods. Despite this, there is a degree of controversy surrounding the directionality in which Mla transports lipids. While the initial discovery and subsequent studies have posited that it mediated retrograde lipid transport (removing glycerophospholipids from the outer membrane and returning them to the inner membrane), others have asserted the opposite. This Perspective aims to lay out the evidence in an unbiased, yet critical, manner for Mla-mediated transport in addition to postulation of mechanisms for anterograde lipid transport from the inner to outer membranes.
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49
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Zhang H, Srinivas S, Xu Y, Wei W, Feng Y. Genetic and Biochemical Mechanisms for Bacterial Lipid A Modifiers Associated with Polymyxin Resistance. Trends Biochem Sci 2019; 44:973-988. [PMID: 31279652 DOI: 10.1016/j.tibs.2019.06.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 06/02/2019] [Accepted: 06/05/2019] [Indexed: 01/29/2023]
Abstract
Polymyxins are a group of detergent-like antimicrobial peptides that are the ultimate line of defense against carbapenem-resistant pathogens in clinical settings. Polymyxin resistance primarily originates from structural remodeling of lipid A anchored on bacterial surfaces. We integrate genetic, structural, and biochemical aspects of three major types of lipid A modifiers that have been shown to confer intrinsic colistin resistance. Namely, we highlight ArnT, a glycosyltransferase, EptA, a phosphoethanolamine transferase, and the AlmEFG tripartite system, which is restricted to EI Tor biotype of Vibrio cholerae O1. We also discuss the growing family of mobile colistin resistance (MCR) enzymes, each of which is analogous to EptA, and which pose great challenges to global public health.
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Affiliation(s)
- Huimin Zhang
- Department of Pathogen Biology and Microbiology, and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Swaminath Srinivas
- Department of Pathogen Biology and Microbiology, and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China; Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yongchang Xu
- Department of Pathogen Biology and Microbiology, and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wenhui Wei
- Department of Pathogen Biology and Microbiology, and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Youjun Feng
- Department of Pathogen Biology and Microbiology, and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China; College of Animal Sciences, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.
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50
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Aghapour Z, Gholizadeh P, Ganbarov K, Bialvaei AZ, Mahmood SS, Tanomand A, Yousefi M, Asgharzadeh M, Yousefi B, Kafil HS. Molecular mechanisms related to colistin resistance in Enterobacteriaceae. Infect Drug Resist 2019; 12:965-975. [PMID: 31190901 PMCID: PMC6519339 DOI: 10.2147/idr.s199844] [Citation(s) in RCA: 184] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 03/04/2019] [Indexed: 12/16/2022] Open
Abstract
Colistin is an effective antibiotic for treatment of most multidrug-resistant Gram-negative bacteria. It is used currently as a last-line drug for infections due to severe Gram-negative bacteria followed by an increase in resistance among Gram-negative bacteria. Colistin resistance is considered a serious problem, due to a lack of alternative antibiotics. Some bacteria, including Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacteriaceae members, such as Escherichia coli, Salmonella spp., and Klebsiella spp. have an acquired resistance against colistin. However, other bacteria, including Serratia spp., Proteus spp. and Burkholderia spp. are naturally resistant to this antibiotic. In addition, clinicians should be alert to the possibility of colistin resistance among multidrug-resistant bacteria and development through mutation or adaptation mechanisms. Rapidly emerging bacterial resistance has made it harder for us to rely completely on the discovery of new antibiotics; therefore, we need to have logical approaches to use old antibiotics, such as colistin. This review presents current knowledge about the different mechanisms of colistin resistance.
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Affiliation(s)
- Zahra Aghapour
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Pourya Gholizadeh
- Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | | | - Suhad Saad Mahmood
- Department of Biotechnology, College of Science, University of Baghdad, Baghdad, Iraq
| | - Asghar Tanomand
- Department of Microbiology, Maragheh University of Medical Sciences, Maragheh, Iran
| | - Mehdi Yousefi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Asgharzadeh
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Bahman Yousefi
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Samadi Kafil
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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