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Wan Y, Myall AC, Boonyasiri A, Bolt F, Ledda A, Mookerjee S, Weiße AY, Getino M, Turton JF, Abbas H, Prakapaite R, Sabnis A, Abdolrasouli A, Malpartida-Cardenas K, Miglietta L, Donaldson H, Gilchrist M, Hopkins KL, Ellington MJ, Otter JA, Larrouy-Maumus G, Edwards AM, Rodriguez-Manzano J, Didelot X, Barahona M, Holmes AH, Jauneikaite E, Davies F. Integrated analysis of patient networks and plasmid genomes reveals a regional, multi-species outbreak of carbapenemase-producing Enterobacterales carrying both blaIMP and mcr-9 genes. J Infect Dis 2024:jiae019. [PMID: 38245822 DOI: 10.1093/infdis/jiae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 01/02/2024] [Accepted: 01/19/2024] [Indexed: 01/22/2024] Open
Abstract
BACKGROUND Carbapenemase-producing Enterobacterales (CPE) are challenging in healthcare, with resistance to multiple classes of antibiotics. This study describes the emergence of IMP-encoding CPE amongst diverse Enterobacterales species between 2016 and 2019 across a London regional network. METHODS We performed a network analysis of patient pathways, using electronic health records, to identify contacts between IMP-encoding CPE positive patients. Genomes of IMP-encoding CPE isolates were overlayed with patient contacts to imply potential transmission events. RESULTS Genomic analysis of 84 Enterobacterales isolates revealed diverse species (predominantly Klebsiella spp, Enterobacter spp, E. coli); 86% (72/84) harboured an IncHI2 plasmid carrying blaIMP and colistin resistance gene mcr-9 (68/72). Phylogenetic analysis of IncHI2 plasmids identified three lineages showing significant association with patient contacts and movements between four hospital sites and across medical specialities, which was missed on initial investigations. CONCLUSIONS Combined, our patient network and plasmid analyses demonstrate an interspecies, plasmid-mediated outbreak of blaIMPCPE, which remained unidentified during standard investigations. With DNA sequencing and multi-modal data incorporation, the outbreak investigation approach proposed here provides a framework for real-time identification of key factors causing pathogen spread. Plasmid-level outbreak analysis reveals that resistance spread may be wider than suspected, allowing more interventions to stop transmission within hospital networks.
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Affiliation(s)
- Yu Wan
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Ashleigh C Myall
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Department of Mathematics, Imperial College London, London, United Kingdom
| | - Adhiratha Boonyasiri
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Frances Bolt
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Imperial College Healthcare NHS Trust, London, United Kingdom
- Centre for Antimicrobial Optimisation, Hammersmith Hospital, Imperial College London, Du Cane Road, London, United Kingdom
| | - Alice Ledda
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
- HCAI, Fungal, AMR, AMU & Sepsis Division, UK Health Security Agency, London, United Kingdom
| | | | - Andrea Y Weiße
- School of Biological Sciences, University of Edinburgh, Scotland, United Kingdom
- School of Informatics, University of Edinburgh, Scotland, United Kingdom
| | - Maria Getino
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Jane F Turton
- HCAI, Fungal, AMR, AMU & Sepsis Division, UK Health Security Agency, London, United Kingdom
| | - Hala Abbas
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Department of Microbiology, North West London Pathology, London, United Kingdom
| | - Ruta Prakapaite
- MRC Centre for Molecular Bacteriology and Infection, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | | | - Kenny Malpartida-Cardenas
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, United Kingdom
| | - Luca Miglietta
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, United Kingdom
| | - Hugo Donaldson
- Department of Microbiology, North West London Pathology, London, United Kingdom
| | - Mark Gilchrist
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Katie L Hopkins
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- HCAI, Fungal, AMR, AMU & Sepsis Division, UK Health Security Agency, London, United Kingdom
| | - Matthew J Ellington
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Reference Services Division, UK Health Security Agency, London, United Kingdom
| | - Jonathan A Otter
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Gerald Larrouy-Maumus
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Jesus Rodriguez-Manzano
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Centre for Antimicrobial Optimisation, Hammersmith Hospital, Imperial College London, Du Cane Road, London, United Kingdom
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, United Kingdom
| | - Xavier Didelot
- School of Life Sciences and Department of Statistics, University of Warwick, United Kingdom
| | - Mauricio Barahona
- Department of Mathematics, Imperial College London, London, United Kingdom
| | - Alison H Holmes
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Imperial College Healthcare NHS Trust, London, United Kingdom
- Centre for Antimicrobial Optimisation, Hammersmith Hospital, Imperial College London, Du Cane Road, London, United Kingdom
| | - Elita Jauneikaite
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Frances Davies
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom
- Imperial College Healthcare NHS Trust, London, United Kingdom
- Department of Microbiology, North West London Pathology, London, United Kingdom
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Sabnis A, Edwards AM. Lipopolysaccharide as an antibiotic target. Biochim Biophys Acta Mol Cell Res 2023; 1870:119507. [PMID: 37268022 DOI: 10.1016/j.bbamcr.2023.119507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 04/18/2023] [Accepted: 05/14/2023] [Indexed: 06/04/2023]
Abstract
Gram-negative bacteria, including Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii are amongst the highest priority drug-resistant pathogens, for which new antibiotics are urgently needed. Whilst antibiotic drug development is inherently challenging, this is particularly true for Gram-negative bacteria due to the presence of the outer membrane, a highly selective permeability barrier that prevents the ingress of several classes of antibiotic. This selectivity is largely due to an outer leaflet composed of the glycolipid lipopolysaccharide (LPS), which is essential for the viability of almost all Gram-negative bacteria. This essentiality, coupled with the conservation of the synthetic pathway across species and recent breakthroughs in our understanding of transport and membrane homeostasis has made LPS an attractive target for novel antibiotic drug development. Several different targets have been explored and small molecules developed that show promising activity in vitro. However, these endeavours have met limited success in clinical testing and the polymyxins, discovered more than 70 years ago, remain the only LPS-targeting drugs to enter the clinic thus far. In this review, we will discuss efforts to develop therapeutic inhibitors of LPS synthesis and transport and the reasons for limited success, and explore new developments in understanding polymyxin mode of action and the identification of new analogues with reduced toxicity and enhanced activity.
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Affiliation(s)
- Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London SW7 2AZ, UK
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London SW7 2AZ, UK.
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Wan Y, Sabnis A, Mumin Z, Potterill I, Jauneikaite E, Brown CS, Ellington MJ, Edwards A, Sriskandan S. IS 1-related large-scale deletion of chromosomal regions harbouring the oxygen-insensitive nitroreductase gene nfsB causes nitrofurantoin heteroresistance in Escherichia coli. Microb Genom 2023; 9:001102. [PMID: 37672334 PMCID: PMC10569738 DOI: 10.1099/mgen.0.001102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/16/2023] [Indexed: 09/07/2023] Open
Abstract
Nitrofurantoin is a broad-spectrum first-line antimicrobial used for managing uncomplicated urinary tract infection (UTI). Loss-of-function mutations in chromosomal genes nfsA, nfsB and ribE of Escherichia coli are known to reduce nitrofurantoin susceptibility. Here, we report the discovery of nitrofurantoin heteroresistance in E. coli clinical isolates and a novel genetic mechanism associated with this phenomenon. Subpopulations with lower nitrofurantoin susceptibility than major populations (hereafter, nitrofurantoin-resistant subpopulations) in two E. coli blood isolates (previously whole-genome sequenced) were identified using population analysis profiling. Each isolate was known to have a loss-of-function mutation in nfsA. From each isolate, four nitrofurantoin-resistant isolates were derived at a nitrofurantoin concentration of 32 mg l-1, and a comparator isolate was obtained without any nitrofurantoin exposure. Genomes of derived isolates were sequenced on Illumina and Nanopore MinION systems. Genetic variation between isolates was determined based on genome assemblies and read mapping. Nitrofurantoin minimum inhibitory concentrations (MICs) of both blood isolates were 64 mg l-1, with MICs of major nitrofurantoin-susceptible populations varying from 4 to 8 mg l-1. Two to 99 c.f.u. per million demonstrated growth at the nitrofurantoin concentration of 32 mg l-1, which is distinct from that of a homogeneously susceptible or resistant isolate. Derived nitrofurantoin-resistant isolates had 11-66 kb deletions in chromosomal regions harbouring nfsB, and all deletions were immediately adjacent to IS1-family insertion sequences. Our findings demonstrate that the IS1-associated large-scale genetic deletion is a hitherto unrecognized mechanism of nitrofurantoin heteroresistance and could compromise UTI management. Further, frequencies of resistant subpopulations from nitrofurantoin-heteroresistant isolates may challenge conventional nitrofurantoin susceptibility testing in clinical settings.
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Affiliation(s)
- Yu Wan
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, UK
- HCAI, Fungal, AMR, AMU and Sepsis Division, UK Health Security Agency, London, UK
| | - Akshay Sabnis
- Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Zaynab Mumin
- Reference Services Division, National Infection Service, UK Health Security Agency, London, UK
| | - Isabelle Potterill
- Reference Services Division, National Infection Service, UK Health Security Agency, London, UK
| | - Elita Jauneikaite
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, UK
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, UK
| | - Colin S. Brown
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, UK
- HCAI, Fungal, AMR, AMU and Sepsis Division, UK Health Security Agency, London, UK
| | - Matthew J. Ellington
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, UK
- HCAI, Fungal, AMR, AMU and Sepsis Division, UK Health Security Agency, London, UK
| | - Andrew Edwards
- Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Shiranee Sriskandan
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, UK
- Centre for Bacterial Resistance Biology, Imperial College London, London, UK
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Murphy RA, Coates M, Thrane S, Sabnis A, Harrison J, Schelenz S, Edwards AM, Vorup-Jensen T, Davies JC. Synergistic Activity of Repurposed Peptide Drug Glatiramer Acetate with Tobramycin against Cystic Fibrosis Pseudomonas aeruginosa. Microbiol Spectr 2022; 10:e0081322. [PMID: 35727066 PMCID: PMC9430792 DOI: 10.1128/spectrum.00813-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 06/01/2022] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is the most common pathogen infecting the lungs of people with cystic fibrosis (CF), causing both acute and chronic infections. Intrinsic and acquired antibiotic resistance, coupled with the physical barriers resulting from desiccated CF sputum, allow P. aeruginosa to colonize and persist in spite of antibiotic treatment. As well as the specific difficulties in eradicating P. aeruginosa from CF lungs, P. aeruginosa is also subject to the wider, global issue of antimicrobial resistance. Glatiramer acetate (GA) is a peptide drug, used in the treatment of multiple sclerosis (MS), which has been shown to have moderate antipseudomonal activity. Other antimicrobial peptides (AMPs) have been shown to be antibiotic resistance breakers, potentiating the activities of antibiotics when given in combination, restoring and/or enhancing antibiotic efficacy. Growth, viability, MIC determinations, and synergy analysis showed that GA improved the efficacy of tobramycin (TOB) against reference strains of P. aeruginosa, reducing TOB MICs and synergizing with the aminoglycoside. This was also the case for clinical strains from people with CF. GA significantly reduced the MIC50 of TOB for viable cells from 1.69 mg/L (95% confidence interval [CI], 0.26 to 8.97) to 0.62 mg/L (95% CI, 0.15 to 3.94; P = 0.002) and the MIC90 for viable cells from 7.00 mg/L (95% CI, 1.18 to 26.50) to 2.20 mg/L (95% CI, 0.99 to 15.03; P = 0.001), compared to results with TOB only. Investigation of mechanisms of GA activity showed that GA resulted in significant disruption of outer membranes, depolarization of cytoplasmic membranes, and permeabilization of P. aeruginosa and was the only agent tested (including cationic AMPs) to significantly affect all three mechanisms. IMPORTANCE The antimicrobial resistance crisis urgently requires solutions to the lost efficacy of antibiotics. The repurposing of drugs already in clinical use, with strong safety profiles, as antibiotic adjuvants to restore the efficacy of antibiotics is an important avenue to alleviating the resistance crisis. This research shows that a clinically used drug from outside infection treatment, glatiramer acetate, reduces the concentration of tobramycin required to be effective in treating Pseudomonas aeruginosa, based on analyses of both reference and clinical respiratory isolates from people with cystic fibrosis. The two agents acted synergistically against P. aeruginosa, being more effective combined in vitro than predicted for their combination. As a peptide drug, glatiramer acetate functions similarly to many antimicrobial peptides, interacting with and disrupting the P. aeruginosa cell wall and permeabilizing bacterial cells, thereby allowing tobramycin to work. Our findings demonstrate that glatiramer acetate is a strong candidate for repurposing as an antibiotic resistance breaker of pathogenic P. aeruginosa.
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Affiliation(s)
- Ronan A. Murphy
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Matthew Coates
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Sophia Thrane
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | | | - Silke Schelenz
- King’s College Hospital NHS Foundation Trust, KingsPath Clinical Diagnostics Pathology Services, London, United Kingdom
| | - Andrew M. Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | | | - Jane C. Davies
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, United Kingdom
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Dhanorkar M, Sabnis A, Kale S. Perfect home composting of biodegradable waste resources for reducing carbon foot print and climate change associated with global warming – a microbiological approach. CM 2022. [DOI: 10.18137/cardiometry.2022.22.185190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Huge amounts of organic biodegradable waste resources are thrown on dumping yards in India and neighboring Asian countries every day. It is estimated that 40-50% of total solid waste collected daily is biodegradable in India. Mumbai, a 1% population of the country, generates about 2500 MT of biodegradable waste. The African continent is no exception to this colossal wastage of natural resources. Barring few countries in the developed world where these waste resources are handled appropriately and environmentally friendly and converted to good quality compost, the story is the same worldwide. This waste resource amounting to millions of metric tonnes is one of the key sources of biomethane escaping in the environment. It is also directly responsible for global warming and associated climatic changes. However, the waste resource generators have been permitted to wash off their hands in not taking care of small amounts of wastages. The result is huge sprawling dumping yards in civilized areas Small measures taken by individuals can make vast changes in the situation. The main reason for this centralized issue is that the decentralized generation of the waste resource is not tackled at that level. This method has two key factors. The method is based entirely on bacterial decomposition without involving any insects. It is also fast and can achieve conversion in 24 to 72 hours. A sincere approach supported by technological improvisation will make it successful and prevent huge amounts of bio-methane from escaping into the environment, which would certainly slow down global warming significantly and help arrest climate changes to a perceptible level. It would also be in tandem with the law of conservation of matter. The generation of pure organic manure will help in recovering the degrading topsoil layer of the country. A perfectly sustainable solution can be offered if all individuals play their part.
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Abstract
The polymyxin and lipopeptide classes of antibiotics are membrane-targeting drugs of last resort used to treat infections caused by multi-drug-resistant pathogens. Despite similar structures, these two antibiotic classes have distinct modes of action and clinical uses. The polymyxins target lipopolysaccharide in the membranes of most Gram-negative species and are often used to treat infections caused by carbapenem-resistant species such as Escherichia coli, Acinetobacter baumannii and Pseudomonas aeruginosa. By contrast, the lipopeptide daptomycin requires membrane phosphatidylglycerol for activity and is only used to treat infections caused by drug-resistant Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. However, despite having distinct targets, both antibiotic classes cause membrane disruption, are potently bactericidal in vitro and share similarities in resistance mechanisms. Furthermore, there are concerns about the efficacy of these antibiotics, and there is increasing interest in using both polymyxins and daptomycin in combination therapies to improve patient outcomes. In this review article, we will explore what is known about these distinct but structurally similar classes of antibiotics, discuss recent advances in the field and highlight remaining gaps in our knowledge.
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Affiliation(s)
- Elizabeth V K Ledger
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK
| | - Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK
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Humphrey M, Larrouy-Maumus GJ, Furniss RCD, Mavridou DAI, Sabnis A, Edwards AM. Colistin resistance in Escherichia coli confers protection of the cytoplasmic but not outer membrane from the polymyxin antibiotic. Microbiology (Reading) 2021; 167. [PMID: 34723787 PMCID: PMC8743629 DOI: 10.1099/mic.0.001104] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Colistin is a polymyxin antibiotic of last resort for the treatment of infections caused by multi-drug-resistant Gram-negative bacteria. By targeting lipopolysaccharide (LPS), the antibiotic disrupts both the outer and cytoplasmic membranes, leading to bacterial death and lysis. Colistin resistance in Escherichia coli occurs via mutations in the chromosome or the acquisition of mobilized colistin-resistance (mcr) genes. Both these colistin-resistance mechanisms result in chemical modifications to the LPS, with positively charged moieties added at the cytoplasmic membrane before the LPS is transported to the outer membrane. We have previously shown that MCR-1-mediated LPS modification protects the cytoplasmic but not the outer membrane from damage caused by colistin, enabling bacterial survival. However, it remains unclear whether this observation extends to colistin resistance conferred by other mcr genes, or resistance due to chromosomal mutations. Using a panel of clinical E. coli that had acquired mcr −1, –1.5, −2, –3, −3.2 or −5, or had acquired polymyxin resistance independently of mcr genes, we found that almost all isolates were susceptible to colistin-mediated permeabilization of the outer, but not cytoplasmic, membrane. Furthermore, we showed that permeabilization of the outer membrane of colistin-resistant isolates by the polymyxin is in turn sufficient to sensitize bacteria to the antibiotic rifampicin, which normally cannot cross the LPS monolayer. These findings demonstrate that colistin resistance in these E. coli isolates is due to protection of the cytoplasmic but not outer membrane from colistin-mediated damage, regardless of the mechanism of resistance.
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Affiliation(s)
- Madeleine Humphrey
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK.,Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK
| | - Gerald J Larrouy-Maumus
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK
| | - R Christopher D Furniss
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Despoina A I Mavridou
- Department of Molecular Biosciences, University of Texas at Austin, Austin, 78712, Texas, USA
| | - Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK
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Murphy R, Sabnis A, Harrison J, Schelenz S, Edwards A, Vorup-Jensen T, Davies J. 520: The antimicrobial peptide glatiramer acetate disrupts pseudomonal cell membranes through interaction with lipopolysaccharide. J Cyst Fibros 2021. [DOI: 10.1016/s1569-1993(21)01944-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Sabnis A, Hagart KLH, Klöckner A, Becce M, Evans LE, Furniss RCD, Mavridou DAI, Murphy R, Stevens MM, Davies JC, Larrouy-Maumus GJ, Clarke TB, Edwards AM. Colistin kills bacteria by targeting lipopolysaccharide in the cytoplasmic membrane. eLife 2021; 10:e65836. [PMID: 33821795 PMCID: PMC8096433 DOI: 10.7554/elife.65836] [Citation(s) in RCA: 144] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/31/2021] [Indexed: 12/21/2022] Open
Abstract
Colistin is an antibiotic of last resort, but has poor efficacy and resistance is a growing problem. Whilst it is well established that colistin disrupts the bacterial outer membrane (OM) by selectively targeting lipopolysaccharide (LPS), it was unclear how this led to bacterial killing. We discovered that MCR-1 mediated colistin resistance in Escherichia coli is due to modified LPS at the cytoplasmic rather than OM. In doing so, we also demonstrated that colistin exerts bactericidal activity by targeting LPS in the cytoplasmic membrane (CM). We then exploited this information to devise a new therapeutic approach. Using the LPS transport inhibitor murepavadin, we were able to cause LPS accumulation in the CM of Pseudomonas aeruginosa, which resulted in increased susceptibility to colistin in vitro and improved treatment efficacy in vivo. These findings reveal new insight into the mechanism by which colistin kills bacteria, providing the foundations for novel approaches to enhance therapeutic outcomes.
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Affiliation(s)
- Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondonUnited Kingdom
| | - Katheryn LH Hagart
- MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondonUnited Kingdom
| | - Anna Klöckner
- MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondonUnited Kingdom
- Department of Bioengineering, Imperial College LondonLondonUnited Kingdom
- Department of Materials, Imperial College LondonLondonUnited Kingdom
- Institute of Biomedical Engineering, Imperial College LondonLondonUnited Kingdom
| | - Michele Becce
- Department of Bioengineering, Imperial College LondonLondonUnited Kingdom
- Department of Materials, Imperial College LondonLondonUnited Kingdom
- Institute of Biomedical Engineering, Imperial College LondonLondonUnited Kingdom
| | - Lindsay E Evans
- MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondonUnited Kingdom
- Department of Chemistry, Imperial College London, Molecular Sciences Research HubLondonUnited Kingdom
| | - R Christopher D Furniss
- MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondonUnited Kingdom
| | - Despoina AI Mavridou
- Department of Molecular Biosciences, University of Texas at AustinAustinUnited States
| | - Ronan Murphy
- National Heart and Lung Institute, Imperial College LondonLondonUnited Kingdom
- Department of Paediatric Respiratory Medicine, Royal Brompton HospitalLondonUnited Kingdom
| | - Molly M Stevens
- Department of Bioengineering, Imperial College LondonLondonUnited Kingdom
- Department of Materials, Imperial College LondonLondonUnited Kingdom
- Institute of Biomedical Engineering, Imperial College LondonLondonUnited Kingdom
| | - Jane C Davies
- National Heart and Lung Institute, Imperial College LondonLondonUnited Kingdom
- Department of Paediatric Respiratory Medicine, Royal Brompton HospitalLondonUnited Kingdom
| | - Gérald J Larrouy-Maumus
- MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondonUnited Kingdom
| | - Thomas B Clarke
- MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondonUnited Kingdom
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondonUnited Kingdom
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Sweeney E, Sabnis A, Edwards AM, Harrison F. Effect of host-mimicking medium and biofilm growth on the ability of colistin to kill Pseudomonas aeruginosa. Microbiology (Reading) 2020; 166:1171-1180. [PMID: 33253080 PMCID: PMC7819359 DOI: 10.1099/mic.0.000995] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In vivo biofilms cause recalcitrant infections with extensive and unpredictable antibiotic tolerance. Here, we demonstrate increased tolerance of colistin by Pseudomonas aeruginosa when grown in medium that mimics cystic fibrosis (CF) sputum versus standard medium in in vitro biofilm assays, and drastically increased tolerance when grown in an ex vivo CF model versus the in vitro assay. We used colistin conjugated to the fluorescent dye BODIPY to assess the penetration of the antibiotic into ex vivo biofilms and showed that poor penetration partly explains the high doses of drug necessary to kill bacteria in these biofilms. The ability of antibiotics to penetrate the biofilm matrix is key to their clinical success, but hard to measure. Our results demonstrate both the importance of reduced entry into the matrix in in vivo-like biofilm, and the tractability of using a fluorescent tag and benchtop fluorimeter to assess antibiotic entry into biofilms. This method could be a relatively quick, cheap and useful addition to diagnostic and drug development pipelines, allowing the assessment of drug entry into biofilms, in in vivo-like conditions, prior to more detailed tests of biofilm killing.
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Affiliation(s)
- Esther Sweeney
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
| | - Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London SW7 2AZ, UK
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London SW7 2AZ, UK
| | - Freya Harrison
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
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Chew J, Lloyd S, Okimoto R, Sabnis A, Nakakura E, Corvera C, Zimel M, Horvai A, Cho S, Wustrack R, Gottschalk A, O'Donnell R, Jahan T, Braunstein S. Outcomes of Elderly Patients with Soft Tissue Sarcoma of the Extremities. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.1002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Affiliation(s)
- Akshay Sabnis
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Elizabeth V. K. Ledger
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Vera Pader
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Andrew M. Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
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Hrkach J, Von Hoff D, Ali MM, Andrianova E, Auer J, Campbell T, De Witt D, Figa M, Figueiredo M, Horhota A, Low S, McDonnell K, Peeke E, Retnarajan B, Sabnis A, Schnipper E, Song JJ, Song YH, Summa J, Tompsett D, Troiano G, Van Geen Hoven T, Wright J, LoRusso P, Kantoff PW, Bander NH, Sweeney C, Farokhzad OC, Langer R, Zale S. Preclinical Development and Clinical Translation of a PSMA-Targeted Docetaxel Nanoparticle with a Differentiated Pharmacological Profile. Sci Transl Med 2012; 4:128ra39. [DOI: 10.1126/scitranslmed.3003651] [Citation(s) in RCA: 872] [Impact Index Per Article: 72.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Wang H, Tan F, Sabnis A, Fu X, Volarath P, Harrison R. Pluggable application server framework. Conf Proc IEEE Eng Med Biol Soc 2006; 2006:2021-2024. [PMID: 17946084 DOI: 10.1109/iembs.2006.259692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Building a system based on variants of disparate individual components/programs is usually a challenging task. The components/programs are not designed to communicate with each other but the whole system construction does require a seamless collaboration among them. In this paper, targeting at protein structure prediction, a pluggable application server framework is presented. The framework is capable of combining various existing programs into an efficient unit and the design is devoted to provide a model which is able to integrate heterogeneous components/programs into the system quickly without modifying their codes. Based on the model, different components can be plugged into the system with easy configuration, which would lead to a self-configurable and adaptive system. A protein structure prediction server implementation was developed by applying the design model and the real implementation emphasizes the efficiency and simplicity of the system construction. The method and model are generic and can be applied to other system design as well.
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Affiliation(s)
- H Wang
- Dept. of Comput. Sci., Georgia State Univ., Atlanta, GA 30303, USA
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Abstract
BACKGROUND Percutaneous endoscopic gastrostomy (PEG) has been an invaluable method for obtaining long-term enteral access and represents one of the first forays in the field of minimally invasive surgery. However, the traditional "pull" method for PEG tube placement continues to have some disadvantages, especially in patients with near-obstructive head and neck cancers. METHODS We describe a new "SLiC" technique for establishing percutaneous gastrostomy using a radially expandable trocar. RESULTS This technique is initially developed and refined on a porcine model and then successfully implemented on five human patients. CONCLUSION The SLiC technique can be done safely and efficiently with a pediatric-sized gastroscope and avoids the need for radiation from fluoroscopy. It is a good alternative for obtaining enteral access in patients who would otherwise not be well suited for a traditional PEG tube.
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Affiliation(s)
- A Sabnis
- Minimally Invasive Surgery Center, Department of General Surgery, Cleveland Clinic Foundation, George Washington University, Washington, DC, USA.
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Fisher ER, Shoemaker RH, Sabnis A. Relationship of hyperplasia to cancer in 3-methylcholanthrene-induced mammary tumorogenesis. J Transl Med 1975; 33:33-42. [PMID: 1142740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Light microscopic study of the evolution of 3-methylcholanthrene-induced mammary tumors in Wistar-Furth rats revealed a seriation of changes proceeding from early hyperplasia (8 days) to advanced hyperplasia (57 days) and cancer (78 days). Ultrastructurally, cellular changes in advanced hyperplasia and cancer were indistinguishable, being characterized by nuclear chromatin clumping, prominent nucleoli, cytoplasmic polyribosomal aggregates and pseudopodal extensions, and prominent Golgi structures. These features, as well as the lack of limiting lamina basalia, allowed for their distinction from the cells of early hyperplasia. Further, only nodules of both advantanced hyperplasia and cancer were transplantable in syngeneic recipients. Chromosomal aberrations were qualitatively similar in cells obtained from all lesions but were progressively more frequent. Although these findings do not allow for the discrimination of advanced hyperplasia and cancer, they indicate their close pathogenetic relationship as well as the very early occurrence of chromosomal alterations in the development of mammary cancer in this model system.
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