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Schumann A, Gaballa A, Wiedmann M. The multifaceted roles of phosphoethanolamine-modified lipopolysaccharides: from stress response and virulence to cationic antimicrobial resistance. Microbiol Mol Biol Rev 2024:e0019323. [PMID: 39382292 DOI: 10.1128/mmbr.00193-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2024] Open
Abstract
SUMMARYLipopolysaccharides (LPS) are an integral part of the outer membrane of Gram-negative bacteria and play essential structural and functional roles in maintaining membrane integrity as well as in stress response and virulence. LPS comprises a membrane-anchored lipid A group, a sugar-based core region, and an O-antigen formed by repeating oligosaccharide units. 3-Deoxy-D-manno-octulosonic acid-lipid A (Kdo2-lipid A) is the minimum LPS component required for bacterial survival. While LPS modifications are not essential, they play multifaceted roles in stress response and host-pathogen interactions. Gram-negative bacteria encode several distinct LPS-modifying phosphoethanolamine transferases (PET) that add phosphoethanolamine (pEtN) to lipid A or the core region of LPS. The pet genes differ in their genomic locations, regulation mechanisms, and modification targets of the encoded enzyme, consistent with their various roles in different growth niches and under varied stress conditions. The discovery of mobile colistin resistance genes, which represent lipid A-modifying pet genes that are encoded on mobile elements and associated with resistance to the last-resort antibiotic colistin, has led to substantial interest in PETs and pEtN-modified LPS over the last decade. Here, we will review the current knowledge of the functional diversity of pEtN-based LPS modifications, including possible roles in niche-specific fitness advantages and resistance to host-produced antimicrobial peptides, and discuss how the genetic and structural diversities of PETs may impact their function. An improved understanding of the PET group will further enhance our comprehension of the stress response and virulence of Gram-negative bacteria and help contextualize host-pathogen interactions.
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Affiliation(s)
- Anna Schumann
- Department of Food Science, Cornell University, Ithaca, New York, USA
- Graduate Field of Biomedical and Biological Sciences, Cornell University, Ithaca, New York, USA
| | - Ahmed Gaballa
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, New York, USA
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2
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Hanpaibool C, Ounjai P, Yotphan S, Mulholland AJ, Spencer J, Ngamwongsatit N, Rungrotmongkol T. Enhancement by pyrazolones of colistin efficacy against mcr-1-expressing E. coli: an in silico and in vitro investigation. J Comput Aided Mol Des 2023; 37:479-489. [PMID: 37488458 DOI: 10.1007/s10822-023-00519-z] [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: 03/31/2023] [Accepted: 07/05/2023] [Indexed: 07/26/2023]
Abstract
Owing to the emergence of antibiotic resistance, the polymyxin colistin has been recently revived to treat acute, multidrug-resistant Gram-negative bacterial infections. Positively charged colistin binds to negatively charged lipids and damages the outer membrane of Gram-negative bacteria. However, the MCR-1 protein, encoded by the mobile colistin resistance (mcr) gene, is involved in bacterial colistin resistance by catalysing phosphoethanolamine (PEA) transfer onto lipid A, neutralising its negative charge, and thereby reducing its interaction with colistin. Our preliminary results showed that treatment with a reference pyrazolone compound significantly reduced colistin minimal inhibitory concentrations in Escherichia coli expressing mcr-1 mediated colistin resistance (Hanpaibool et al. in ACS Omega, 2023). A docking-MD combination was used in an ensemble-based docking approach to identify further pyrazolone compounds as candidate MCR-1 inhibitors. Docking simulations revealed that 13/28 of the pyrazolone compounds tested are predicted to have lower binding free energies than the reference compound. Four of these were chosen for in vitro testing, with the results demonstrating that all the compounds tested could lower colistin MICs in an E. coli strain carrying the mcr-1 gene. Docking of pyrazolones into the MCR-1 active site reveals residues that are implicated in ligand-protein interactions, particularly E246, T285, H395, H466, and H478, which are located in the MCR-1 active site and which participate in interactions with MCR-1 in ≥ 8/10 of the lowest energy complexes. This study establishes pyrazolone-induced colistin susceptibility in E. coli carrying the mcr-1 gene, providing a method for the development of novel treatments against colistin-resistant bacteria.
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Affiliation(s)
- Chonnikan Hanpaibool
- Center of Excellence in Biocatalyst and Sustainable Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Puey Ounjai
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
- Center of Excellence On Environmental Health and Toxicology, Office of Higher Education Commission, Ministry of Education, Bangkok, 10400, Thailand
| | - Sirilata Yotphan
- Center of Excellence for Innovation in Chemistry (PERCH-CIC), Department of Chemistry, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
| | - James Spencer
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - Natharin Ngamwongsatit
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand.
- Laboratory of Bacteria, Veterinary Diagnostic Center, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand.
| | - Thanyada Rungrotmongkol
- Center of Excellence in Biocatalyst and Sustainable Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
- Program in Bioinformatics and Computational Biology, Graduate School, Chulalongkorn University, Bangkok, 10330, Thailand.
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3
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Rogga V, Kosalec I. Untying the anchor for the lipopolysaccharide: lipid A structural modification systems offer diagnostic and therapeutic options to tackle polymyxin resistance. Arh Hig Rada Toksikol 2023; 74:145-166. [PMID: 37791675 PMCID: PMC10549895 DOI: 10.2478/aiht-2023-74-3717] [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: 01/01/2023] [Revised: 01/01/2023] [Accepted: 07/01/2023] [Indexed: 10/05/2023] Open
Abstract
Polymyxin antibiotics are the last resort for treating patients in intensive care units infected with multiple-resistant Gram-negative bacteria. Due to their polycationic structure, their mode of action is based on an ionic interaction with the negatively charged lipid A portion of the lipopolysaccharide (LPS). The most prevalent polymyxin resistance mechanisms involve covalent modifications of lipid A: addition of the cationic sugar 4-amino-L-arabinose (L-Ara4N) and/or phosphoethanolamine (pEtN). The modified structure of lipid A has a lower net negative charge, leading to the repulsion of polymyxins and bacterial resistance to membrane disruption. Genes encoding the enzymatic systems involved in these modifications can be transferred either through chromosomes or mobile genetic elements. Therefore, new approaches to resistance diagnostics have been developed. On another note, interfering with these enzymatic systems might offer new therapeutic targets for drug discovery. This literature review focuses on diagnostic approaches based on structural changes in lipid A and on the therapeutic potential of molecules interfering with these changes.
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Affiliation(s)
- Vanessa Rogga
- University of Zagreb Faculty of Pharmacy and Biochemistry, Department of Microbiology, Zagreb, Croatia
| | - Ivan Kosalec
- University of Zagreb Faculty of Pharmacy and Biochemistry, Department of Microbiology, Zagreb, Croatia
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4
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Li X, Jiang T, Wu C, Kong Y, Ma Y, Wu J, Xie X, Zhang J, Ruan Z. Molecular epidemiology and genomic characterization of a plasmid-mediated mcr-10 and blaNDM-1 co-harboring multidrug-resistant Enterobacter asburiae. Comput Struct Biotechnol J 2023; 21:3885-3893. [PMID: 37602227 PMCID: PMC10433016 DOI: 10.1016/j.csbj.2023.08.004] [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: 02/06/2023] [Revised: 07/29/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023] Open
Abstract
Colistin is considered as one of the last-resort antimicrobial agents for treating multidrug-resistant bacterial infections. Multidrug-resistant E. asburiae has been increasingly isolated from clinical patients, which posed a great challenge for antibacterial treatment. This study aimed to report a mcr-10 and blaNDM-1 co-carrying E. asburiae clinical isolate 5549 conferred a high-level resistance against colistin. Antibiotic susceptibility testing was performed using the microdilution broth method. Transferability of mcr-10 and blaNDM-1-carrying plasmids were investigated by conjugation experiments. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to identify modifications in lipid A. Whole genome sequencing and phylogenetic analysis between strain 5549 and a total of 301 E. asburiae genomes retrieved from NCBI database were performed. The genetic characteristics of mcr-10 and blaNDM-1-bearing plasmids were also analyzed. Our study indicated that strain 5549 showed extensively antibiotic-resistant trait, including colistin and carbapenem resistance. The mcr-10 and blaNDM-1 were carried by IncFIB/IncFII type p5549_mcr-10 (159417 bp) and IncN type p5549_NDM-1 (63489 bp), respectively. Conjugation assays identified that only the blaNDM-1-carrying plasmid could be successfully transferred to E. coli J53. Interestingly, mcr-10 did not mediate colistin resistance when it was cloned into E. coli DH5α. Mass spectrometry analysis showed the lipid A palmitoylation of the C-lacyl-oxo-acyl chain to the chemical structure of lipid A at m/z 2063 in strain 5549. In summary, this study is the first to report a mcr-10 and blaNDM-1 co-occurrence E. asburiae recovered from China. Our investigation revealed the distribution of different clonal lineage of E. asburiae with epidemiology perspective and the underlying mechanisms of colistin resistance. Active surveillance is necessary to control the further dissemination of multidrug-resistant E. asburiae.
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Affiliation(s)
- Xinyang Li
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Tian Jiang
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Clinical Laboratory, The Affiliated Wenling Hospital, Wenzhou Medical University, Taizhou, China
| | - Chenghao Wu
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yingying Kong
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Yilei Ma
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Jianyong Wu
- Department of Clinical Laboratory, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China
| | - Xinyou Xie
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Jun Zhang
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Zhi Ruan
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
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5
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Seethalakshmi PS, Rajeev R, Prabhakaran A, Kiran GS, Selvin J. The menace of colistin resistance across globe: Obstacles and opportunities in curbing its spread. Microbiol Res 2023; 270:127316. [PMID: 36812837 DOI: 10.1016/j.micres.2023.127316] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 11/27/2022] [Accepted: 02/01/2023] [Indexed: 02/11/2023]
Abstract
Colistin-resistance in bacteria is a big concern for public health, since it is a last resort antibiotic to treat infectious diseases of multidrug resistant and carbapenem resistant Gram-negative pathogens in clinical settings. The emergence of colistin resistance in aquaculture and poultry settings has escalated the risks associated with colistin resistance in environment as well. The staggering number of reports pertaining to the rise of colistin resistance in bacteria from clinical and non-clinical settings is disconcerting. The co-existence of colistin resistant genes with other antibiotic resistant genes introduces new challenges in combatting antimicrobial resistance. Some countries have banned the manufacture, sale and distribution of colistin and its formulations for food producing animals. However, to tackle the issue of antimicrobial resistance, a one health approach initiative, inclusive of human, animal, and environmental health needs to be developed. Herein, we review the recent reports in colistin resistance in bacteria of clinical and non-clinical settings, deliberating on the new findings obtained regarding the development of colistin resistance. This review also discusses the initiatives implemented globally in mitigating colistin resistance, their strength and weakness.
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Affiliation(s)
- P S Seethalakshmi
- Department of Microbiology, Pondicherry University, Puducherry 605014, India.
| | - Riya Rajeev
- Department of Microbiology, Pondicherry University, Puducherry 605014, India.
| | | | - George Seghal Kiran
- Department of Food Science and Technology, Pondicherry University, Puducherry 605014, India.
| | - Joseph Selvin
- Department of Microbiology, Pondicherry University, Puducherry 605014, India.
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6
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Onyedibe KI, Nemeth AM, Dayal N, Smith RD, Lamptey J, Ernst RK, Melander RJ, Melander C, Sintim HO. Re-sensitization of Multidrug-Resistant and Colistin-Resistant Gram-Negative Bacteria to Colistin by Povarov/Doebner-Derived Compounds. ACS Infect Dis 2023; 9:283-295. [PMID: 36651182 PMCID: PMC10547215 DOI: 10.1021/acsinfecdis.2c00417] [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: 01/19/2023]
Abstract
Colistin, typically viewed as the antibiotic of last resort to treat infections caused by multidrug-resistant (MDR) Gram-negative bacteria, had fallen out of favor due to toxicity issues. The recent increase in clinical usage of colistin has resulted in colistin-resistant isolates becoming more common. To counter this threat, we have investigated previously reported compounds, HSD07 and HSD17, and developed 13 compounds with more desirable drug-like properties for colistin sensitization against 16 colistin-resistant bacterial strains, three of which harbor the plasmid-borne mobile colistin resistance (mcr-1). Lead compound HSD1624, which has a lower LogDpH7.4 (2.46) compared to HSD07 (>5.58), reduces the minimum inhibitory concentration (MIC) of colistin against Pseudomonas aeruginosa strain TRPA161 to 0.03 μg/mL from 1024 μg/mL (34,000-fold reduction). Checkerboard assays revealed that HSD1624 and analogues are also synergistic with colistin against colistin-resistant strains of Escherichia coli, Acinetobacter baumannii, and Klebsiella pneumoniae. Preliminary mechanism of action studies indicate that HSD1624 exerts its action differently depending on the bacterial species. Time-kill studies suggested that HSD1624 in combination with 0.5 μg/mL colistin was bactericidal to extended-spectrum beta-lactamase (ESBL)-producing E. coli, as well as to E. coli harboring mcr-1, while against P. aeruginosa TRPA161, the combination was bacteriostatic. Mechanistically, HSD1624 increased membrane permeability in K. pneumoniae harboring a plasmid containing the mcr-1 gene but did not increase radical oxygen species (ROS), while a combination of 15 μM HSD1624 and 0.5 μg/mL colistin significantly increased ROS in P. aeruginosa TRPA161. HSD1624 was not toxic to mammalian red blood cells (up to 226 μM).
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Affiliation(s)
- Kenneth I Onyedibe
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana47907, United States
- Center for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, Indiana47906, United States
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, West Lafayette, Indiana47906, United States
| | - Ansley M Nemeth
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana46556, United States
| | - Neetu Dayal
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana47907, United States
- Center for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, Indiana47906, United States
| | - Richard D Smith
- Department of Microbial Pathogenesis, University of Maryland-Baltimore, Baltimore, Maryland21201, United States
| | - Jones Lamptey
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana47907, United States
- Center for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, Indiana47906, United States
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland-Baltimore, Baltimore, Maryland21201, United States
| | - Roberta J Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana46556, United States
| | - Christian Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana46556, United States
| | - Herman O Sintim
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana47907, United States
- Center for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, Indiana47906, United States
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, West Lafayette, Indiana47906, United States
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7
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Feng S, Liang W, Li J, Chen Y, Zhou D, Liang L, Lin D, Li Y, Zhao H, Du H, Dai M, Qin LN, Bai F, Doi Y, Zhong LL, Tian GB. MCR-1-dependent lipid remodelling compromises the viability of Gram-negative bacteria. Emerg Microbes Infect 2022; 11:1236-1249. [PMID: 35437117 PMCID: PMC9067951 DOI: 10.1080/22221751.2022.2065934] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The global dissemination of the mobilized colistin resistance gene, mcr-1, threatens human health. Recent studies by our group and others have shown that the withdrawal of colistin as a feed additive dramatically reduced the prevalence of mcr-1. Although it is accepted that the rapid reduction in mcr-1 prevalence may have resulted, to some extent, from the toxic effects of MCR-1, the detailed mechanism remains unclear. Here, we found that MCR-1 damaged the outer membrane (OM) permeability in Escherichia coli and Klebsiella pneumonia and that this event was associated with MCR-1-mediated cell shrinkage and death during the stationary phase. Notably, the capacity of MCR-1-expressing cells for recovery from the stationary phase under improved conditions was reduced in a time-dependent manner. We also showed that mutations in the potential lipid-A-binding pocket of MCR-1, but not in the catalytic domain, restored OM permeability and cell viability. During the stationary phase, PbgA, a sensor of periplasmic lipid-A and LpxC production that performed the first step in lipid-A synthesis, was reduced after MCR-1 expression, suggesting that MCR-1 disrupted lipid homeostasis. Consistent with this, the overexpression of LpxC completely reversed the MCR-1-induced OM permeability defect. We propose that MCR-1 causes lipid remodelling that results in an OM permeability defect, thus compromising the viability of Gram-negative bacteria. These findings extended our understanding of the effect of MCR-1 on bacterial physiology and provided a potential strategy for eliminating drug-resistant bacteria.
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Affiliation(s)
- Siyuan Feng
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China
| | - Wanfei Liang
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China
| | - Jiachen Li
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China
| | - Yong Chen
- School of Laboratory Medicine, Chengdu Medical College, Chengdu, People's Republic of China
| | - Dianrong Zhou
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China
| | - Lujie Liang
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China
| | - Daixi Lin
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China
| | - Yaxin Li
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China
| | - Hui Zhao
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
| | - Huihui Du
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing, People's Republic of China
| | - Min Dai
- School of Laboratory Medicine, Chengdu Medical College, Chengdu, People's Republic of China
| | - Li-Na Qin
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Fan Bai
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing, People's Republic of China.,Beijing Advanced Innovation Center for Genomics (ICG), Peking University, Beijing, People's Republic of China
| | - Yohei Doi
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Microbiology and Infectious Diseases, School of Medicine, Fujita Health University, Aichi, Japan
| | - Lan-Lan Zhong
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China
| | - Guo-Bao Tian
- Program in Pathobiology, The Fifth Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangdong, People's Republic of China.,Key Laboratory of Tropical Diseases Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, People's Republic of China.,School of Medicine, Xizang Minzu University, Xianyang, People's Republic of China
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8
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Synergistic Membrane Disturbance Improves the Antibacterial Performance of Polymyxin B. Polymers (Basel) 2022; 14:polym14204316. [PMID: 36297894 PMCID: PMC9611124 DOI: 10.3390/polym14204316] [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: 09/12/2022] [Revised: 09/29/2022] [Accepted: 10/09/2022] [Indexed: 01/24/2023] Open
Abstract
Drug-resistant Gram-negative bacteria pose a serious threat to public health, and polymyxin B (PMB) is clinically used as a last-line therapy for the treatment of infections caused by these pathogens. However, the appearance of PMB resistance calls for an effort to develop new approaches to improve its antibacterial performance. In this work, a new type of nanocomposite, composed of PMB molecules being chemically decorated on the surface of graphene oxide (GO) nanosheets, was designed, which showed potent antibacterial ability through synergistically and physically disturbing the bacterial membrane. The as-fabricated PMB@GO nanocomposites demonstrated an enhanced bacterial-killing efficiency, with a minimum inhibitory concentration (MIC) value half of that of free PMB (with an MIC value as low as 0.5 μg mL-1 over Escherichia coli), and a bacterial viability less than one fourth of that of PMB (with a bacterial reduction of 60% after 3 h treatment, and 90% after 6 h incubation). Furthermore, the nanocomposite displayed moderate cytotoxicity or hemolysis effect, with cellular viabilities over 85% at concentrations up to 16 times the MIC value. Studies on antibacterial mechanism revealed that the synergy between PMB molecules and GO nanosheets greatly facilitated the vertical insertion of the nanocomposite into the lipid membrane, leading to membrane disturbance and permeabilization. Our results demonstrate a physical mechanism for improving the antibacterial performance of PMB and developing advanced antibacterial agents for better clinic uses.
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9
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Fu L, Li X, Zhang S, Dong Y, Fang W, Gao L. Polymyxins induce lipid scrambling and disrupt the homeostasis of Gram-negative bacteria membrane. Biophys J 2022; 121:3486-3498. [PMID: 35964158 PMCID: PMC9515121 DOI: 10.1016/j.bpj.2022.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/01/2022] [Accepted: 08/10/2022] [Indexed: 11/30/2022] Open
Abstract
Polymyxins are increasingly used as the last-line therapeutic option for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, efforts to address the resistance in superbugs are compromised by a poor understanding of the bactericidal modes because high-resolution detection of the cell structure is still lacking. By performing molecular dynamics simulations at a coarse-grained level, here we show that polymyxin B (PmB) disrupts Gram-negative bacterial membranes by altering lipid homeostasis and asymmetry. We found that the binding of PmBs onto the asymmetric outer membrane (OM) loosens the packing of lipopolysaccharides (LPS) and induces unbalanced bending torque between the inner and outer leaflets, which in turn triggers phospholipids to flip from the inner leaflet to the outer leaflet to compensate for the stress deformation. Meanwhile, some LPSs may be detained on the inner membrane (IM). Then, the lipid-scrambled OM undergoes phase separation. Defects are created at the boundaries between LPS-rich domains and phospholipid-rich domains, which consequently facilitate the uptake of PmB across the OM. Finally, PmBs target LPSs detained on the IM and similarly perturb the IM. This lipid Scramble, membrane phase Separation, and peptide Translocation model depicts a novel mechanism by which polymyxins kill bacteria and sheds light on developing a new generation of polymyxins or antibiotic adjuvants with improved killing activities and higher therapeutic indices.
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Affiliation(s)
- Lei Fu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Xiangyuan Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Shan Zhang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Yi Dong
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Weihai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Lianghui Gao
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China.
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