1
|
Choi N, Choi E, Cho YJ, Kim MJ, Choi HW, Lee EJ. A shared mechanism of multidrug resistance in laboratory-evolved uropathogenic Escherichia coli. Virulence 2024; 15:2367648. [PMID: 38899601 PMCID: PMC11195483 DOI: 10.1080/21505594.2024.2367648] [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: 12/26/2023] [Accepted: 06/09/2024] [Indexed: 06/21/2024] Open
Abstract
The emergence of multidrug-resistant bacteria poses a significant threat to human health, necessitating a comprehensive understanding of their underlying mechanisms. Uropathogenic Escherichia coli (UPEC), the primary causative agent of urinary tract infections, is frequently associated with multidrug resistance and recurrent infections. To elucidate the mechanism of resistance of UPEC to beta-lactam antibiotics, we generated ampicillin-resistant UPEC strains through continuous exposure to low and high levels of ampicillin in the laboratory, referred to as Low AmpR and High AmpR, respectively. Whole-genome sequencing revealed that both Low and High AmpR strains contained mutations in the marR, acrR, and envZ genes. The High AmpR strain exhibited a single additional mutation in the nlpD gene. Using protein modeling and qRT-PCR analyses, we validated the contributions of each mutation in the identified genes to antibiotic resistance in the AmpR strains, including a decrease in membrane permeability, increased expression of multidrug efflux pump, and inhibition of cell lysis. Furthermore, the AmpR strain does not decrease the bacterial burden in the mouse bladder even after continuous antibiotic treatment in vivo, implicating the increasing difficulty in treating host infections caused by the AmpR strain. Interestingly, ampicillin-induced mutations also result in multidrug resistance in UPEC, suggesting a common mechanism by which bacteria acquire cross-resistance to other classes of antibiotics.
Collapse
Affiliation(s)
- Nakjun Choi
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Eunna Choi
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Yong-Joon Cho
- Department of Molecular Bioscience, Multidimensional Genomics Research Center, College of Biomedical Science, Kangwon National University, Chuncheon, South Korea
| | - Min Jung Kim
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Hae Woong Choi
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Eun-Jin Lee
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| |
Collapse
|
2
|
Ekdahl AM, Julien T, Suraj S, Kribelbauer J, Tavazoie S, Freddolino PL, Contreras LM. Multiscale regulation of nutrient stress responses in Escherichia coli from chromatin structure to small regulatory RNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599902. [PMID: 38979244 PMCID: PMC11230228 DOI: 10.1101/2024.06.20.599902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Recent research has indicated the presence of heterochromatin-like regions of extended protein occupancy and transcriptional silencing of bacterial genomes. We utilized an integrative approach to track chromatin structure and transcription in E. coli K-12 across a wide range of nutrient conditions. In the process, we identified multiple loci which act similarly to facultative heterochromatin in eukaryotes, normally silenced but permitting expression of genes under specific conditions. We also found a strong enrichment of small regulatory RNAs (sRNAs) among the set of differentially expressed transcripts during nutrient stress. Using a newly developed bioinformatic pipeline, the transcription factors regulating sRNA expression were bioinformatically predicted, with experimental follow-up revealing novel relationships for 36 sRNA-transcription factors candidates. Direct regulation of sRNA expression was confirmed by mutational analysis for five sRNAs of metabolic interest: IsrB, CsrB and CsrC, GcvB, and GadY. Our integrative analysis thus reveals additional layers of complexity in the nutrient stress response in E. coli and provides a framework for revealing similar poorly understood regulatory logic in other organisms.
Collapse
Affiliation(s)
- Alyssa M Ekdahl
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Tatiana Julien
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Sahana Suraj
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Judith Kribelbauer
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
| | - Saeed Tavazoie
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
| | - P Lydia Freddolino
- Department of Biological Chemistry and Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| |
Collapse
|
3
|
Rivera-Galindo MA, Aguirre-Garrido F, Garza-Ramos U, Villavicencio-Pulido JG, Fernández Perrino FJ, López-Pérez M. Relevance of the Adjuvant Effect between Cellular Homeostasis and Resistance to Antibiotics in Gram-Negative Bacteria with Pathogenic Capacity: A Study of Klebsiella pneumoniae. Antibiotics (Basel) 2024; 13:490. [PMID: 38927157 PMCID: PMC11200652 DOI: 10.3390/antibiotics13060490] [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: 04/05/2024] [Revised: 05/17/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024] Open
Abstract
Antibiotic resistance has become a global issue. The most significant risk is the acquisition of these mechanisms by pathogenic bacteria, which can have a severe clinical impact and pose a public health risk. This problem assumes that bacterial fitness is a constant phenomenon and should be approached from an evolutionary perspective to develop the most appropriate and effective strategies to contain the emergence of strains with pathogenic potential. Resistance mechanisms can be understood as adaptive processes to stressful conditions. This review examines the relevance of homeostatic regulatory mechanisms in antimicrobial resistance mechanisms. We focus on the interactions in the cellular physiology of pathogenic bacteria, particularly Gram-negative bacteria, and specifically Klebsiella pneumoniae. From a clinical research perspective, understanding these interactions is crucial for comprehensively understanding the phenomenon of resistance and developing more effective drugs and treatments to limit or attenuate bacterial sepsis, since the most conserved adjuvant phenomena in bacterial physiology has turned out to be more optimized and, therefore, more susceptible to alterations due to pharmacological action.
Collapse
Affiliation(s)
- Mildred Azucena Rivera-Galindo
- Doctorado en Ciencias Biológicas y de la Salud Universidad Autónoma Metropolitana, Ciudad de México, México Universidad Autónoma Metropolitana-Unidad Xochimilco Calz, del Hueso 1100, Coapa, Villa Quietud, Coyoacán CP 04960, Mexico;
| | - Félix Aguirre-Garrido
- Environmental Sciences Department, Division of Biological and Health Sciences, Autonomous Metropolitan University (Lerma Unit), Av. de las Garzas N◦ 10, Col. El Panteón, Lerma de Villada CP 52005, Mexico; (F.A.-G.); (J.G.V.-P.)
| | - Ulises Garza-Ramos
- Centro de Investigación Sobre Enfermedades Infecciosas (CISEI), Instituto Nacional de Salud Pública (INSP), Cuernavaca CP 62100, Mexico;
| | - José Geiser Villavicencio-Pulido
- Environmental Sciences Department, Division of Biological and Health Sciences, Autonomous Metropolitan University (Lerma Unit), Av. de las Garzas N◦ 10, Col. El Panteón, Lerma de Villada CP 52005, Mexico; (F.A.-G.); (J.G.V.-P.)
| | - Francisco José Fernández Perrino
- Department of Biotechnology, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana-Unidad Iztapalapa, Av. San Rafael Atlixco 186, Leyes de Reforma, México City CP 09340, Mexico;
| | - Marcos López-Pérez
- Environmental Sciences Department, Division of Biological and Health Sciences, Autonomous Metropolitan University (Lerma Unit), Av. de las Garzas N◦ 10, Col. El Panteón, Lerma de Villada CP 52005, Mexico; (F.A.-G.); (J.G.V.-P.)
| |
Collapse
|
4
|
Sykes EME, White D, McLaughlin S, Kumar A. Salicylic acids and pathogenic bacteria: new perspectives on an old compound. Can J Microbiol 2024; 70:1-14. [PMID: 37699258 DOI: 10.1139/cjm-2023-0123] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Salicylic acids have been used in human and veterinary medicine for their anti-pyretic, anti-inflammatory, and analgesic properties for centuries. A key role of salicylic acid-immune modulation in response to microbial infection-was first recognized during studies of their botanical origin. The effects of salicylic acid on bacterial physiology are diverse. In many cases, they impose selective pressures leading to development of cross-resistance to antimicrobial compounds. Initial characterization of these interactions was in Escherichia coli, where salicylic acid activates the multiple antibiotic resistance (mar) operon, resulting in decreased antibiotic susceptibility. Studies suggest that stimulation of the mar phenotype presents similarly in closely related Enterobacteriaceae. Salicylic acids also affect virulence in many opportunistic pathogens by decreasing their ability to form biofilms and increasing persister cell populations. It is imperative to understand the effects of salicylic acid on bacteria of various origins to illuminate potential links between environmental microbes and their clinically relevant antimicrobial-resistant counterparts. This review provides an update on known effects of salicylic acid and key derivatives on a variety of bacterial pathogens, offers insights to possible potentiation of current treatment options, and highlights cellular regulatory networks that have been established during the study of this important class of medicines.
Collapse
Affiliation(s)
- Ellen M E Sykes
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Dawn White
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Sydney McLaughlin
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Ayush Kumar
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| |
Collapse
|
5
|
Chubiz LM. The Mar, Sox, and Rob Systems. EcoSal Plus 2023; 11:eesp00102022. [PMID: 37220096 PMCID: PMC10729928 DOI: 10.1128/ecosalplus.esp-0010-2022] [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: 09/14/2022] [Accepted: 03/03/2023] [Indexed: 01/28/2024]
Abstract
Environments inhabited by Enterobacteriaceae are diverse and often stressful. This is particularly true for Escherichia coli and Salmonella during host association in the gastrointestinal systems of animals. There, E. coli and Salmonella must survive exposure to various antimicrobial compounds produced or ingested by their host. A myriad of changes to cellular physiology and metabolism are required to achieve this feat. A central regulatory network responsible for sensing and responding to intracellular chemical stressors like antibiotics are the Mar, Sox, and Rob systems found throughout the Enterobacteriaceae. Each of these distinct regulatory networks controls expression of an overlapping set of downstream genes whose collective effects result in increased resistance to a wide array of antimicrobial compounds. This collection of genes is known as the mar-sox-rob regulon. This review will provide an overview of the mar-sox-rob regulon and molecular architecture of the Mar, Sox, and Rob systems.
Collapse
Affiliation(s)
- Lon M. Chubiz
- Department of Biology, University of Missouri–St. Louis, St. Louis, Missouri, USA
- Biochemistry and Biotechnology Program, University of Missouri–St. Louis, St. Louis, Missouri, USA
| |
Collapse
|
6
|
Sionov RV, Steinberg D. Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:1239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
Collapse
Affiliation(s)
- Ronit Vogt Sionov
- The Biofilm Research Laboratory, The Institute of Biomedical and Oral Research, The Faculty of Dental Medicine, Hadassah Medical School, The Hebrew University, Jerusalem 9112102, Israel;
| | | |
Collapse
|
7
|
Glover G, Voliotis M, Łapińska U, Invergo BM, Soanes D, O'Neill P, Moore K, Nikolic N, Petrov PG, Milner DS, Roy S, Heesom K, Richards TA, Tsaneva-Atanasova K, Pagliara S. Nutrient and salt depletion synergistically boosts glucose metabolism in individual Escherichia coli cells. Commun Biol 2022; 5:385. [PMID: 35444215 PMCID: PMC9021252 DOI: 10.1038/s42003-022-03336-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/30/2022] [Indexed: 12/16/2022] Open
Abstract
The interaction between a cell and its environment shapes fundamental intracellular processes such as cellular metabolism. In most cases growth rate is treated as a proximal metric for understanding the cellular metabolic status. However, changes in growth rate might not reflect metabolic variations in individuals responding to environmental fluctuations. Here we use single-cell microfluidics-microscopy combined with transcriptomics, proteomics and mathematical modelling to quantify the accumulation of glucose within Escherichia coli cells. In contrast to the current consensus, we reveal that environmental conditions which are comparatively unfavourable for growth, where both nutrients and salinity are depleted, increase glucose accumulation rates in individual bacteria and population subsets. We find that these changes in metabolic function are underpinned by variations at the translational and posttranslational level but not at the transcriptional level and are not dictated by changes in cell size. The metabolic response-characteristics identified greatly advance our fundamental understanding of the interactions between bacteria and their environment and have important ramifications when investigating cellular processes where salinity plays an important role.
Collapse
Affiliation(s)
- Georgina Glover
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - Margaritis Voliotis
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Department of Mathematics, University of Exeter, Stocker Road, Exeter, UK
| | - Urszula Łapińska
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4Q, UK
| | - Brandon M Invergo
- Translational Research Exchange at Exeter, University of Exeter, Exeter, UK
| | - Darren Soanes
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4Q, UK
| | - Paul O'Neill
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4Q, UK
| | - Karen Moore
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4Q, UK
| | - Nela Nikolic
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Institute of Science and Technology Austria, 3400, Klosterneuburg, Austria
| | - Peter G Petrov
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - David S Milner
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK
| | - Sumita Roy
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4Q, UK
| | - Kate Heesom
- University of Bristol Proteomics Facility, University Walk, Bristol, BS8 1TD, UK
| | - Thomas A Richards
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK
| | - Krasimira Tsaneva-Atanasova
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Department of Mathematics, University of Exeter, Stocker Road, Exeter, UK
- Department of Bioinformatics and Mathematical Modelling, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 105 Acad. G. Bonchev Str., 1113, Sofia, Bulgaria
| | - Stefano Pagliara
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4Q, UK.
| |
Collapse
|
8
|
Paes Leme RC, da Silva RB. Antimicrobial Activity of Non-steroidal Anti-inflammatory Drugs on Biofilm: Current Evidence and Potential for Drug Repurposing. Front Microbiol 2021; 12:707629. [PMID: 34385992 PMCID: PMC8353384 DOI: 10.3389/fmicb.2021.707629] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/05/2021] [Indexed: 12/20/2022] Open
Abstract
It has been demonstrated that some non-steroidal anti-inflammatory drugs (NSAIDs), like acetylsalicylic acid, diclofenac, and ibuprofen, have anti-biofilm activity in concentrations found in human pharmacokinetic studies, which could fuel an interest in repurposing these well tolerated drugs as adjunctive therapies for biofilm-related infections. Here we sought to review the currently available data on the anti-biofilm activity of NSAIDs and its relevance in a clinical context. We performed a systematic literature review to identify the most commonly tested NSAIDs drugs in the last 5 years, the bacterial species that have demonstrated to be responsive to their actions, and the emergence of resistance to these molecules. We found that most studies investigating NSAIDs' activity against biofilms were in vitro, and frequently tested non-clinical bacterial isolates, which may not adequately represent the bacterial populations that cause clinically-relevant biofilm-related infections. Furthermore, studies concerning NSAIDs and antibiotic resistance are scarce, with divergent outcomes. Although the potential to use NSAIDs to control biofilm-related infections seems to be an exciting avenue, there is a paucity of studies that tested these drugs using appropriate in vivo models of biofilm infections or in controlled human clinical trials to support their repurposing as anti-biofilm agents.
Collapse
Affiliation(s)
- Rodrigo Cuiabano Paes Leme
- Laboratório Especial de Microbiologia Clínica (LEMC), Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.,Department of Infectious Diseases, Centro Universitário de Volta Redonda, Volta Redonda, Brazil
| | | |
Collapse
|
9
|
Majewski P, Gutowska A, Sacha P, Schneiders T, Talalaj M, Majewska P, Zebrowska A, Ojdana D, Wieczorek P, Hauschild T, Kowalczuk O, Niklinski J, Radziwon P, Tryniszewska E. Expression of AraC/XylS stress response regulators in two distinct carbapenem-resistant Enterobacter cloacae ST89 biotypes. J Antimicrob Chemother 2021; 75:1146-1150. [PMID: 31960042 DOI: 10.1093/jac/dkz569] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 12/09/2019] [Accepted: 12/20/2019] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The growing incidence of MDR Gram-negative bacteria is a rapidly emerging challenge in modern medicine. OBJECTIVES We sought to establish the role of intrinsic drug-resistance regulators in combination with specific genetic mutations in 11 Enterobacter cloacae isolates obtained from a single patient within a 7 week period. METHODS The molecular characterization of eight carbapenem-resistant and three carbapenem-susceptible E. cloacae ST89 isolates included expression-level analysis and WGS. Quantitative PCR included: (i) chromosomal cephalosporinase gene (ampC); (ii) membrane permeability factor genes, e.g. ompF, ompC, acrA, acrB and tolC; and (iii) intrinsic regulatory genes, e.g. ramA, ampR, rob, marA and soxS, which confer reductions in antibiotic susceptibility. RESULTS In this study we describe the influence of the alterations in membrane permeability (ompF and ompC levels), intrinsic regulatory genes (ramA, marA, soxS) and intrinsic chromosomal cephalosporinase AmpC on reductions in carbapenem susceptibility of E. cloacae clinical isolates. Interestingly, only the first isolate possessed the acquired VIM-4 carbapenemase, which has been lost in subsequent isolates. The remaining XDR E. cloacae ST89 isolates presented complex carbapenem-resistance pathways, which included perturbations in permeability of bacterial membranes mediated by overexpression of ramA, encoding an AraC/XylS global regulator. Moreover, susceptible isolates differed significantly from other isolates in terms of marA down-regulation and soxS up-regulation. CONCLUSIONS Molecular mechanisms of resistance among carbapenem-resistant E. cloacae included production of acquired VIM-4 carbapenemase, significant alterations in membrane permeability due to increased expression of ramA, encoding an AraC/XylS global regulator, and the overproduction of chromosomal AmpC cephalosporinase.
Collapse
Affiliation(s)
- Piotr Majewski
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok, Bialystok, Poland
| | - Anna Gutowska
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok, Bialystok, Poland
| | - Pawel Sacha
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok, Bialystok, Poland
| | | | - Mariola Talalaj
- Department of Anaesthesiology and Intensive Care with Postoperative Unit, University Children's Clinical Hospital, Bialystok, Poland
| | | | | | - Dominika Ojdana
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok, Bialystok, Poland
| | - Piotr Wieczorek
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok, Bialystok, Poland
| | - Tomasz Hauschild
- Department of Microbiology, Institute of Biology, University of Bialystok, Bialystok, Poland
| | - Oksana Kowalczuk
- Department of Clinical Molecular Biology, Medical University of Bialystok, Bialystok, Poland
| | - Jacek Niklinski
- Department of Clinical Molecular Biology, Medical University of Bialystok, Bialystok, Poland
| | - Piotr Radziwon
- Regional Centre for Transfusion Medicine, Bialystok, Poland.,Department of Hematology, Medical University of Bialystok, Bialystok, Poland
| | - Elzbieta Tryniszewska
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok, Bialystok, Poland
| |
Collapse
|
10
|
Azargun R, Gholizadeh P, Sadeghi V, Hosainzadegan H, Tarhriz V, Memar MY, Pormohammad A, Eyvazi S. Molecular mechanisms associated with quinolone resistance in Enterobacteriaceae: review and update. Trans R Soc Trop Med Hyg 2021; 114:770-781. [PMID: 32609840 DOI: 10.1093/trstmh/traa041] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 04/09/2020] [Accepted: 05/20/2020] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Quinolones are broad-spectrum antibiotics, which are used for the treatment of different infectious diseases associated with Enterobacteriaceae. During recent decades, the wide use as well as overuse of quinolones against diverse infections has led to the emergence of quinolone-resistant bacterial strains. Herein, we present the development of quinolone antibiotics, their function and also the different quinolone resistance mechanisms in Enterobacteriaceae by reviewing recent literature. METHODS All data were extracted from Google Scholar search engine and PubMed site, using keywords; quinolone resistance, Enterobacteriaceae, plasmid-mediated quinolone resistance, etc. RESULTS AND CONCLUSION The acquisition of resistance to quinolones is a complex and multifactorial process. The main resistance mechanisms consist of one or a combination of target-site gene mutations altering the drug-binding affinity of target enzymes. Other mechanisms of quinolone resistance are overexpression of AcrAB-tolC multidrug-resistant efflux pumps and downexpression of porins as well as plasmid-encoded resistance proteins including Qnr protection proteins, aminoglycoside acetyltransferase (AAC(6')-Ib-cr) and plasmid-encoded active efflux pumps such as OqxAB and QepA. The elucidation of resistance mechanisms will help researchers to explore new drugs against the resistant strains.
Collapse
Affiliation(s)
- Robab Azargun
- Department of Microbiology, Faculty of Medicine, Maragheh University of Medical Sciences, Maragheh, Iran
| | - Pourya Gholizadeh
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Vahid Sadeghi
- Faculty of Veterinary Medicine, Islamic Azad University, Urmia, Iran
| | - Hasan Hosainzadegan
- Department of Microbiology, Faculty of Medicine, Maragheh University of Medical Sciences, Maragheh, Iran
| | - Vahideh Tarhriz
- Molecular Medicine Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Yousef Memar
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Pormohammad
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shirin Eyvazi
- Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| |
Collapse
|
11
|
Gregorchuk BSJ, Reimer SL, Green KAC, Cartwright NH, Beniac DR, Hiebert SL, Booth TF, Chong PM, Westmacott GR, Zhanel GG, Bay DC. Phenotypic and Multi-Omics Characterization of Escherichia coli K-12 Adapted to Chlorhexidine Identifies the Role of MlaA and Other Cell Envelope Alterations Regulated by Stress Inducible Pathways in CHX Resistance. Front Mol Biosci 2021; 8:659058. [PMID: 34095221 PMCID: PMC8170033 DOI: 10.3389/fmolb.2021.659058] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/09/2021] [Indexed: 11/27/2022] Open
Abstract
Chlorhexidine (CHX) is an essential medicine used as a topical antiseptic in skin and oral healthcare treatments. The widespread use of CHX has increased concerns regarding the development of antiseptic resistance in Enterobacteria and its potential impact on cross-resistance to other antimicrobials. Similar to other cationic antiseptics, resistance to CHX is believed to be driven by three membrane-based mechanisms: lipid synthesis/transport, altered porin expression, and increased efflux pump activity; however, specific gene and protein alterations associated with CHX resistance remain unclear. Here, we adapted Escherichia coli K-12 BW25113 to increasing concentrations of CHX to determine what phenotypic, morphological, genomic, transcriptomic, and proteomic changes occurred. We found that CHX-adapted E. coli isolates possessed no cross-resistance to any other antimicrobials we tested. Scanning electron microscopy imaging revealed that CHX adaptation significantly altered mean cell widths and lengths. Proteomic analyses identified changes in the abundance of porin OmpF, lipid synthesis/transporter MlaA, and efflux pump MdfA. Proteomic and transcriptomic analyses identified that CHX adaptation altered E. coli transcripts and proteins controlling acid resistance (gadE, cdaR) and antimicrobial stress-inducible pathways Mar-Sox-Rob, stringent response systems. Whole genome sequencing analyses revealed that all CHX-resistant isolates had single nucleotide variants in the retrograde lipid transporter gene mlaA as well as the yghQ gene associated with lipid A transport and synthesis. CHX resistant phenotypes were reversible only when complemented with a functional copy of the mlaA gene. Our results highlight the importance of retrograde phospholipid transport and stress response systems in CHX resistance and the consequences of prolonged CHX exposure.
Collapse
Affiliation(s)
- Branden S J Gregorchuk
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Shelby L Reimer
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Kari A C Green
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Nicola H Cartwright
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Daniel R Beniac
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Shannon L Hiebert
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Timothy F Booth
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.,National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Patrick M Chong
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Garrett R Westmacott
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - George G Zhanel
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Denice C Bay
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| |
Collapse
|
12
|
Dekoninck K, Létoquart J, Laguri C, Demange P, Bevernaegie R, Simorre JP, Dehu O, Iorga BI, Elias B, Cho SH, Collet JF. Defining the function of OmpA in the Rcs stress response. eLife 2020; 9:60861. [PMID: 32985973 PMCID: PMC7553776 DOI: 10.7554/elife.60861] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/26/2020] [Indexed: 01/18/2023] Open
Abstract
OmpA, a protein commonly found in the outer membrane of Gram-negative bacteria, has served as a paradigm for the study of β-barrel proteins for several decades. In Escherichia coli, OmpA was previously reported to form complexes with RcsF, a surface-exposed lipoprotein that triggers the Rcs stress response when damage occurs in the outer membrane and the peptidoglycan. How OmpA interacts with RcsF and whether this interaction allows RcsF to reach the surface has remained unclear. Here, we integrated in vivo and in vitro approaches to establish that RcsF interacts with the C-terminal, periplasmic domain of OmpA, not with the N-terminal β-barrel, thus implying that RcsF does not reach the bacterial surface via OmpA. Our results suggest a novel function for OmpA in the cell envelope: OmpA competes with the inner membrane protein IgaA, the downstream Rcs component, for RcsF binding across the periplasm, thereby regulating the Rcs response.
Collapse
Affiliation(s)
- Kilian Dekoninck
- WELBIO, Brussels, Belgium.,de Duve Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Juliette Létoquart
- WELBIO, Brussels, Belgium.,de Duve Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | | | - Pascal Demange
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, Université Paul Sabatier, Toulouse, France
| | - Robin Bevernaegie
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium
| | | | - Olivia Dehu
- de Duve Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Bogdan I Iorga
- de Duve Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium.,Université Paris-Saclay, CNRS UPR 2301, Institut de Chimie des Substances Naturelles, Gif-sur-Yvette, France
| | - Benjamin Elias
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium
| | - Seung-Hyun Cho
- WELBIO, Brussels, Belgium.,de Duve Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Jean-Francois Collet
- WELBIO, Brussels, Belgium.,de Duve Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| |
Collapse
|
13
|
Zhang C, Chen S, Dedkova LM, Hecht SM. Effects of Nucleobase Amino Acids on the Binding of Rob to Its Promoter DNA: Differential Alteration of DNA Affinity and Phenotype. Biochemistry 2020; 59:2111-2119. [PMID: 32412234 DOI: 10.1021/acs.biochem.0c00290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Nucleic acid binding proteins have been studied extensively, but the nature of the interactions that control their affinity, selectivity, and DNA and RNA functions is still not well understood. To understand the nature and functional consequences of such interactions, we introduced nucleobase amino acids at specific positions of the transcriptional regulator Rob protein in vivo and succeeded in demonstrating that an alteration of the protein-DNA affinity can affect specific phenotypes associated with Rob protein-DNA interactions. Previously, we inserted different nucleobase amino acids in lieu of Arg40; this residue is known (via X-ray crystallography) to interact with the micF DNA promoter A-box residue Gua6. The interactions predominantly involved Watson-Crick-like H bonding. The present study focused primarily on the micF DNA promoter B-box; the crystallographically determined interaction involves H bonding between the agmatine moiety of Arg90 within an HTH motif of Rob and a phosphate oxygen anion to the 5'-side of Thy14. We had two main goals, the first of which was to demonstrate enhanced Rob-binding to the micF promoter DNA and the functional consequences resulting from the interaction of micF DNA with Rob analogues containing Arg90 nucleobase mimics. The second was to explore the possible functional consequences of enhancing the protein-DNA affinity with nucleobase replacements, which mechanistically mediate interactions differently than those reported to be operative for specific protein-DNA interactions. Nucleobase replacement at position 90 with Arg isosteres enhanced the Rob protein-micF DNA affinity in parallel with increasing antibiotic and Hg2+ resistance, while aromatic amino acid replacements increased the affinity but not the antibiotic or Hg2+ resistance. The demonstration of an increased affinity through strong base stacking interactions was notable.
Collapse
|
14
|
Integrating CRISPR-Enabled Trackable Genome Engineering and Transcriptomic Analysis of Global Regulators for Antibiotic Resistance Selection and Identification in Escherichia coli. mSystems 2020; 5:5/2/e00232-20. [PMID: 32317390 PMCID: PMC7174635 DOI: 10.1128/msystems.00232-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The growing threat of antimicrobial resistance poses a serious threat to public health care and motivates efforts to understand the means by which resistance acquisition occurs and how this can be combatted. To address these challenges, we expedited the identification of novel mutations that enable complex phenotypic changes that result in improved tolerance to antibiotics by integrating CREATE and transcriptomic analysis of global regulators. The results give us a better understanding of the mechanisms of resistance to tetracycline antibiotics and aminoglycoside antibiotics and also indicate that the method may be used for quickly identifying resistance-related mutations. It is important to expedite our understanding of antibiotic resistance to address the increasing numbers of fatalities and environmental pollution due to the emergence of antibiotic resistance and multidrug-resistant strains. Here, we combined the CRISPR-enabled trackable genome engineering (CREATE) technology and transcriptomic analysis to investigate antibiotic tolerance in Escherichia coli. We developed rationally designed site saturation mutagenesis libraries targeting 23 global regulators to identify fitness-conferring mutations in response to diverse antibiotic stresses. We identified seven novel mutations that confer resistance to the ribosome-targeting antibiotics doxycycline, thiamphenicol, and gentamicin in E. coli. To the best of our knowledge, these mutations that we identified have not been reported previously during treatment with the indicated antibiotics. Transcriptome sequencing-based transcriptome analysis was further employed to evaluate the genome-wide changes in gene expression in E. coli for SoxR G121P and cAMP receptor protein (CRP) V140W reconstructions, and improved fitness in response to doxycycline and gentamicin was seen. In the case of doxycycline, we speculated that SoxR G121P significantly increased the expression of genes involved in carbohydrate metabolism and energy metabolism to promote cell growth for improved adaptation. In the CRP V140W mutant with improved gentamicin tolerance, the expression of several amino acid biosynthesis genes and fatty acid degradation genes was significantly changed, and these changes probably altered the cellular energy state to improve adaptation. These findings have important significance for understanding such nonspecific mechanisms of antibiotic resistance and developing new antibacterial drugs. IMPORTANCE The growing threat of antimicrobial resistance poses a serious threat to public health care and motivates efforts to understand the means by which resistance acquisition occurs and how this can be combatted. To address these challenges, we expedited the identification of novel mutations that enable complex phenotypic changes that result in improved tolerance to antibiotics by integrating CREATE and transcriptomic analysis of global regulators. The results give us a better understanding of the mechanisms of resistance to tetracycline antibiotics and aminoglycoside antibiotics and also indicate that the method may be used for quickly identifying resistance-related mutations.
Collapse
|
15
|
Zhang C, Chen S, Bai X, Dedkova LM, Hecht SM. Alteration of Transcriptional Regulator Rob In Vivo: Enhancement of Promoter DNA Binding and Antibiotic Resistance in the Presence of Nucleobase Amino Acids. Biochemistry 2020; 59:1217-1220. [PMID: 32157864 DOI: 10.1021/acs.biochem.0c00103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The identification of proteins that bind selectively to nucleic acid sequences is an ongoing challenge. We previously synthesized nucleobase amino acids designed to replace proteinogenic amino acids; these were incorporated into proteins to bind specific nucleic acids predictably. An early example involved selective cell free binding of the hnRNP LL RRM1 domain to its i-motif DNA target via Watson-Crick-like H-bonding interactions. In this study, we employ the X-ray crystal structure of transcriptional regulator Rob bound to its micF promoter, which occurred without DNA distortion. Rob proteins modified in vivo with nucleobase amino acids at position 40 exhibited altered DNA promoter binding, as predicted on the basis of their Watson-Crick-like H-bonding interactions with promoter DNA A-box residue Gua-6. Rob protein expression ultimately controls phenotypic changes, including resistance to antibiotics. Although Rob proteins with nucleobase amino acids were expressed in Escherichia coli at levels estimated to be only a fraction of that of the wild-type Rob protein, those modified proteins that bound to the micF promoter more avidly than the wild type in vitro also produced greater resistance to macrolide antibiotics roxithromycin and clarithromycin in vivo, as well as the β-lactam antibiotic ampicillin. Also demonstrated is the statistical significance of altered DNA binding and antibiotic resistance for key Rob analogues. These preliminary findings suggest the ultimate utility of nucleobase amino acids in altering and controlling preferred nucleic acid target sequences by proteins, for probing molecular interactions critical to protein function, and for enhancing phenotypic changes in vivo by regulatory protein analogues.
Collapse
Affiliation(s)
- Chao Zhang
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Shengxi Chen
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Xiaoguang Bai
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Larisa M Dedkova
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Sidney M Hecht
- Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| |
Collapse
|
16
|
Multidrug Resistance Regulators MarA, SoxS, Rob, and RamA Repress Flagellar Gene Expression and Motility in Salmonella enterica Serovar Typhimurium. J Bacteriol 2019; 201:JB.00385-19. [PMID: 31501286 DOI: 10.1128/jb.00385-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/03/2019] [Indexed: 12/21/2022] Open
Abstract
Production of flagella is costly and subject to global multilayered regulation, which is reflected in the hierarchical control of flagellar production in many bacterial species. For Salmonella enterica serovar Typhimurium and its relatives, global regulation of flagellar production primarily occurs through the control of flhDC transcription and mRNA translation. In this study, the roles of the homologous multidrug resistance regulators MarA, SoxS, Rob, and RamA (constituting the mar-sox-rob regulon in S Typhimurium) in regulating flagellar gene expression were explored. Each of these regulators was found to inhibit flagellar gene expression, production of flagella, and motility. To different degrees, repression via these transcription factors occurred through direct interactions with the flhDC promoter, particularly for MarA and Rob. Additionally, SoxS repressed flagellar gene expression via a posttranscriptional pathway, reducing flhDC translation. The roles of these transcription factors in reducing motility in the presence of salicylic acid were also elucidated, adding a genetic regulatory element to the response of S Typhimurium to this well-characterized chemorepellent. Integration of flagellar gene expression into the mar-sox-rob regulon in S Typhimurium contrasts with findings for closely related species such as Escherichia coli, providing an example of plasticity in the mar-sox-rob regulon throughout the Enterobacteriaceae family.IMPORTANCE The mar-sox-rob regulon is a large and highly conserved stress response network in the Enterobacteriaceae family. Although it is well characterized in E. coli, the extent of this regulon in related species is unclear. Here, the control of costly flagellar gene expression is connected to the mar-sox-rob regulon of S Typhimurium, contrasting with the E. coli regulon model. These findings demonstrate the flexibility of the mar-sox-rob regulon to accommodate novel regulatory targets, and they provide evidence for its broader regulatory role within this family of diverse bacteria.
Collapse
|
17
|
Abstract
The transport of small molecules across membranes is essential for the import of nutrients and other energy sources into the cell and, for the export of waste and other potentially harmful byproducts out of the cell. While hydrophobic molecules are permeable to membranes, ions and other small polar molecules require transport via specialized membrane transport proteins . The two major classes of membrane transport proteins are transporters and channels. With our focus here on porins-major class of non-specific diffusion channel proteins , we will highlight some recent structural biology reports and functional assays that have substantially contributed to our understanding of the mechanism that mediates uptake of small molecules, including antibiotics, across the outer membrane of Enterobacteriaceae . We will also review advances in the regulation of porin expression and porin biogenesis and discuss these pathways as new therapeutic targets.
Collapse
Affiliation(s)
- Muriel Masi
- UMR_MD1, Inserm U1261, IRBA, Membranes et Cibles Thérapeutiques, Facultés de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France
| | | | - Jean-Marie Pagès
- UMR_MD1, Inserm U1261, IRBA, Membranes et Cibles Thérapeutiques, Facultés de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
| |
Collapse
|
18
|
Abstract
INTRODUCTION Aspirin (acetylsalicylic acid, ASA) is often co-administered during the treatment of infections. Salicylic acid (SAL), the active metabolite of ASA, has significant effects on bacteria that might improve or (more likely) compromise the effectiveness of antibiotics. Areas covered: In this review, we summarize the interactions between SAL and antibiotics, and describe the underlying mechanisms involved. Expert opinion: In an era of rapidly increasing antibiotic resistance and lack of new antibiotic development, it is important to explore ways to optimize the effectiveness of antimicrobial treatment. This includes a better understanding of the interactions between commonly co-administered drugs. SAL might compromise the effectiveness of antibiotic treatment by inducing phenotypic resistance in bacteria. It can induce phenotypic resistance by up- or downregulating outer membrane proteins or efflux pumps, by upregulating antibiotic targets and by inducing enzymes with degrading activity. Moreover, SAL can increase the frequency of mutations leading to antibiotic resistance.
Collapse
Affiliation(s)
- Petra Zimmermann
- a Department of Paediatrics , The University of Melbourne , Parkville , Australia.,b Infectious Diseases & Microbiology Research Group , Murdoch Children's Research Institute , Parkville , Australia.,c Infectious Diseases Unit , The Royal Children's Hospital Melbourne , Parkville , Australia.,d Infectious Diseases Unit , University of Basel Children's Hospital , Basel , Switzerland
| | - Nigel Curtis
- a Department of Paediatrics , The University of Melbourne , Parkville , Australia.,b Infectious Diseases & Microbiology Research Group , Murdoch Children's Research Institute , Parkville , Australia.,c Infectious Diseases Unit , The Royal Children's Hospital Melbourne , Parkville , Australia
| |
Collapse
|
19
|
Dam S, Pagès JM, Masi M. Stress responses, outer membrane permeability control and antimicrobial resistance in Enterobacteriaceae. MICROBIOLOGY-SGM 2018; 164:260-267. [PMID: 29458656 DOI: 10.1099/mic.0.000613] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Bacteria have evolved several strategies to survive a myriad of harmful conditions in the environment and in hosts. In Gram-negative bacteria, responses to nutrient limitation, oxidative or nitrosative stress, envelope stress, exposure to antimicrobials and other growth-limiting stresses have been linked to the development of antimicrobial resistance. This results from the activation of protective changes to cell physiology (decreased outer membrane permeability), resistance transporters (drug efflux pumps), resistant lifestyles (biofilms, persistence) and/or resistance mutations (target mutations, production of antibiotic modification/degradation enzymes). In targeting and interfering with essential physiological mechanisms, antimicrobials themselves are considered as stresses to which protective responses have also evolved. In this review, we focus on envelope stress responses that affect the expression of outer membrane porins and their impact on antimicrobial resistance. We also discuss evidences that indicate the role of antimicrobials as signaling molecules in activating envelope stress responses.
Collapse
Affiliation(s)
- Sushovan Dam
- UMR_MD-1, Aix-Marseille Univ. & IRBA, 27 Boulevard Jean Moulin, 13005 Marseille, France
| | - Jean-Marie Pagès
- UMR_MD-1, Aix-Marseille Univ. & IRBA, 27 Boulevard Jean Moulin, 13005 Marseille, France
| | - Muriel Masi
- UMR_MD-1, Aix-Marseille Univ. & IRBA, 27 Boulevard Jean Moulin, 13005 Marseille, France
| |
Collapse
|
20
|
Jain K, Saini S. MarRA, SoxSR, and Rob encode a signal dependent regulatory network in Escherichia coli. MOLECULAR BIOSYSTEMS 2017; 12:1901-12. [PMID: 27098660 DOI: 10.1039/c6mb00263c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
When exposed to low concentrations of toxic chemicals, bacteria modulate the expression of a number of cellular processes. Typically, these processes include those related to porin production, dismutases, and metabolic fluxes. In Escherichia coli (E. coli), the expression of these systems is largely controlled by three homologous transcriptional regulators: MarA, SoxS, and Rob. Each of the three regulators responds to distinct chemical signals (salicylate for MarA; paraquat for SoxS; and bipyridyl for Rob) and controls the expression of an overlapping set of downstream targets. In addition, the three systems autoregulate their own expression, and cross-regulate each other's expression. Specifically, MarA is known to activate SoxS expression, and Rob is known to activate MarA expression. In addition, a number of conflicting regulatory interactions are known to exist between the three loci. Thus, the three systems encode a complex regulatory topology with multiple feedback loops, the precise nature of whose interactions or their significance in cellular physiology is not well understood currently. In this work, we focus on understanding the details of this crosstalk between the Mar-Sox-Rob systems in E. coli, and the resulting control and dynamics of the expression of cellular processes by studying gene expression at the population level and at single-cell resolution in wild type and mutants. Our results indicate that the regulatory architecture between MarA, SoxS, and Rob is dependent on the signal (inducer) present in the environment. The regulators, in response to an inducer, form a Feed Forward Loop (FFL), which leads to faster and stronger induction of target genes in the cell, consequently resulting in better cellular growth. Through the FFL, the cell is able to integrate qualitatively different signals in the network, and consequently, control cellular physiology. In addition, we present two intriguing dynamic features of the Mar-Sox-Rob regulon. First, in the presence of salicylate, the activation of target genes via MarA and Rob, at single-cell resolution, is qualitatively different. Second, we report the synergistic activation of target and Mar/Sox systems in the presence of both salicylate and paraquat. These results strongly indicate that there exists a complex control of gene regulation in the Mar-Sox-Rob regulon. Mechanistic details of this control are likely quite complex, and may involve additional regulators.
Collapse
Affiliation(s)
- Kirti Jain
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai - 400 076, India.
| | - Supreet Saini
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai - 400 076, India.
| |
Collapse
|
21
|
Abstract
Antipyretics are some of the most commonly used drugs. Since they are often coadministered with antimicrobial therapy, it is important to understand the interactions between these two classes of drugs. Our review is the first to summarize the antimicrobial effects of antipyretic drugs and the underlying mechanisms involved. Antipyretics can inhibit virus replication, inhibit or promote bacterial or fungal growth, alter the expression of virulence factors, change the surface hydrophobicity of microbes, influence biofilm production, affect the motility, adherence, and metabolism of pathogens, interact with the transport and release of antibiotics by leukocytes, modify the susceptibility of bacteria to antibiotics, and induce or reduce the frequency of mutations leading to antimicrobial resistance. While antipyretics may compromise the efficacy of antimicrobial therapy, they can also be beneficial, for example, in the management of biofilm-associated infections, in reducing virulence factors, in therapy of resistant pathogens, and in inducing synergistic effects. In an era where it is becoming increasingly difficult to find new antimicrobial drugs, targeting virulence factors, enhancing the efficacy of antimicrobial therapy, and reducing resistance may be important strategies.
Collapse
|
22
|
Effects of a Mutation in the gyrA Gene on the Virulence of Uropathogenic Escherichia coli. Antimicrob Agents Chemother 2015; 59:4662-8. [PMID: 26014933 DOI: 10.1128/aac.00665-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 05/18/2015] [Indexed: 01/20/2023] Open
Abstract
Fluoroquinolones are among the drugs most extensively used for the treatment of bacterial infections in human and veterinary medicine. Resistance to quinolones can be chromosome or plasmid mediated. The chromosomal mechanism of resistance is associated with mutations in the DNA gyrase- and topoisomerase IV-encoding genes and mutations in regulatory genes affecting different efflux systems, among others. We studied the role of the acquisition of a mutation in the gyrA gene in the virulence and protein expression of uropathogenic Escherichia coli (UPEC). The HC14366M strain carrying a mutation in the gyrA gene (S83L) was found to lose the capacity to cause cystitis and pyelonephritis mainly due to a decrease in the expression of the fimA, papA, papB, and ompA genes. The levels of expression of the fimA, papB, and ompA genes were recovered on complementing the strain with a plasmid containing the gyrA wild-type gene. However, only a slight recovery was observed in the colonization of the bladder in the GyrA complement strain compared to the mutant strain in a murine model of ascending urinary tract infection. In conclusion, a mutation in the gyrA gene of uropathogenic E. coli reduced the virulence of the bacteria, likely in association with the effect of DNA supercoiling on the expression of several virulence factors and proteins, thereby decreasing their capacity to cause cystitis and pyelonephritis.
Collapse
|
23
|
Kurenbach B, Marjoshi D, Amábile-Cuevas CF, Ferguson GC, Godsoe W, Gibson P, Heinemann JA. Sublethal exposure to commercial formulations of the herbicides dicamba, 2,4-dichlorophenoxyacetic acid, and glyphosate cause changes in antibiotic susceptibility in Escherichia coli and Salmonella enterica serovar Typhimurium. mBio 2015; 6:e00009-15. [PMID: 25805724 PMCID: PMC4453521 DOI: 10.1128/mbio.00009-15] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 02/05/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Biocides, such as herbicides, are routinely tested for toxicity but not for sublethal effects on microbes. Many biocides are known to induce an adaptive multiple-antibiotic resistance phenotype. This can be due to either an increase in the expression of efflux pumps, a reduced synthesis of outer membrane porins, or both. Exposures of Escherichia coli and Salmonella enterica serovar Typhimurium to commercial formulations of three herbicides-dicamba (Kamba), 2,4-dichlorophenoxyacetic acid (2,4-D), and glyphosate (Roundup)-were found to induce a changed response to antibiotics. Killing curves in the presence and absence of sublethal herbicide concentrations showed that the directions and the magnitudes of responses varied by herbicide, antibiotic, and species. When induced, MICs of antibiotics of five different classes changed up to 6-fold. In some cases the MIC increased, and in others it decreased. Herbicide concentrations needed to invoke the maximal response were above current food maximum residue levels but within application levels for all herbicides. Compounds that could cause induction had additive effects in combination. The role of soxS, an inducer of the AcrAB efflux pump, was tested in β-galactosidase assays with soxS-lacZ fusion strains of E. coli. Dicamba was a moderate inducer of the sox regulon. Growth assays with Phe-Arg β-naphtylamide (PAβN), an efflux pump inhibitor, confirmed a significant role of efflux in the increased tolerance of E. coli to chloramphenicol in the presence of dicamba and to kanamycin in the presence of glyphosate. Pathways of exposure with relevance to the health of humans, domestic animals, and critical insects are discussed. IMPORTANCE Increasingly common chemicals used in agriculture, domestic gardens, and public places can induce a multiple-antibiotic resistance phenotype in potential pathogens. The effect occurs upon simultaneous exposure to antibiotics and is faster than the lethal effect of antibiotics. The magnitude of the induced response may undermine antibiotic therapy and substantially increase the probability of spontaneous mutation to higher levels of resistance. The combination of high use of both herbicides and antibiotics in proximity to farm animals and important insects, such as honeybees, might also compromise their therapeutic effects and drive greater use of antibiotics. To address the crisis of antibiotic resistance requires broadening our view of environmental contributors to the evolution of resistance.
Collapse
Affiliation(s)
- Brigitta Kurenbach
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Delphine Marjoshi
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | | | - Gayle C Ferguson
- Institute of Natural and Mathematical Sciences, Massey University, Palmerston North, New Zealand
| | - William Godsoe
- Bio-Protection Centre, Lincoln University, Lincoln, New Zealand
| | - Paddy Gibson
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Jack A Heinemann
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| |
Collapse
|
24
|
Valade E, Davin-Regli A, Bolla JM, Pagès JM. Bacterial Membrane, a Key for Controlling Drug Influx and Efflux. Antibiotics (Basel) 2013. [DOI: 10.1002/9783527659685.ch9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
|
25
|
Improved detection of antibiotic compounds by bacterial reporter strains achieved by manipulations of membrane permeability and efflux capacity. Appl Microbiol Biotechnol 2013; 98:2267-77. [PMID: 23963273 DOI: 10.1007/s00253-013-5176-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 07/20/2013] [Accepted: 08/02/2013] [Indexed: 10/26/2022]
Abstract
The occurrence of pharmaceuticals, including antibacterial compounds, in the environment has been acknowledged as an emerging and troubling issue in environmental safety; their usage is constantly on the rise, and their effects on the environment are only partially understood. Such compounds can accumulate, contaminate the ecosystem, and contribute to the spreading of antibiotic resistance among bacteria, hindering human health. Bioluminescent Escherichia coli reporter strains, engineered to detect antibiotic compounds by fusing the promoter of the global regulator soxS to the Photorhabdus luminescens luxCDABE cassette, were further modified by altering their membrane permeability and efflux capabilities. This was accomplished by introducing several mutations in the efflux system (ΔemrE, ΔacrB, and ΔtolC) and by overexpressing OmpF, a porin located in the outer membrane that allows passive diffusion of molecules. Combinations of these alterations had a cumulative effect in lowering the detection threshold of several antibiotics, in some of the cases to concentrations reported from pharmaceutical-polluted environments.
Collapse
|
26
|
Corona F, Martinez JL. Phenotypic Resistance to Antibiotics. Antibiotics (Basel) 2013; 2:237-55. [PMID: 27029301 PMCID: PMC4790337 DOI: 10.3390/antibiotics2020237] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/22/2013] [Accepted: 04/09/2013] [Indexed: 12/12/2022] Open
Abstract
The development of antibiotic resistance is usually associated with genetic changes, either to the acquisition of resistance genes, or to mutations in elements relevant for the activity of the antibiotic. However, in some situations resistance can be achieved without any genetic alteration; this is called phenotypic resistance. Non-inherited resistance is associated to specific processes such as growth in biofilms, a stationary growth phase or persistence. These situations might occur during infection but they are not usually considered in classical susceptibility tests at the clinical microbiology laboratories. Recent work has also shown that the susceptibility to antibiotics is highly dependent on the bacterial metabolism and that global metabolic regulators can modulate this phenotype. This modulation includes situations in which bacteria can be more resistant or more susceptible to antibiotics. Understanding these processes will thus help in establishing novel therapeutic approaches based on the actual susceptibility shown by bacteria during infection, which might differ from that determined in the laboratory. In this review, we discuss different examples of phenotypic resistance and the mechanisms that regulate the crosstalk between bacterial metabolism and the susceptibility to antibiotics. Finally, information on strategies currently under development for diminishing the phenotypic resistance to antibiotics of bacterial pathogens is presented.
Collapse
Affiliation(s)
- Fernando Corona
- Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049-Madrid, Spain
| | - Jose L Martinez
- Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049-Madrid, Spain.
| |
Collapse
|
27
|
Martins A, Hunyadi A, Amaral L. Mechanisms of resistance in bacteria: an evolutionary approach. Open Microbiol J 2013; 7:53-8. [PMID: 23560029 PMCID: PMC3613773 DOI: 10.2174/1874285801307010053] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 01/22/2013] [Accepted: 01/23/2013] [Indexed: 02/02/2023] Open
Abstract
Acquisition of resistance is one of the major causes of failure in therapy of bacterial infections. According to the World Health Organization (WHO), thousands of deaths caused by Salmonella sp., Escherichia coli, Staphylococcus aureus or Mycobacteria tuberculosis are due to failure in therapy caused by resistance to the chemotherapeutic agents. Understanding the mechanisms of resistance acquisition by the bacterial strains is therefore essential to prevent and overcome resistance. However, it is very difficult to extrapolate from in vitro studies, where the variables are far less and under constant control, as compared to what happens in vivo where the chosen chemotherapeutic, its effective dose, and the patient's immune system are variables that differ substantially case-by-case. The aim of this review is to provide a new perspective on the possible ways by which resistance is acquired by the bacterial strains within the patient, with a special emphasis on the adaptive response of the infecting bacteria to the administered antibiotic.
Collapse
Affiliation(s)
- Ana Martins
- Unidade de Parasitologia e Microbiologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008 Lisboa, Portugal ; Institute of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, Dóm Tér 10, 6720 Szeged, Hungary
| | | | | |
Collapse
|
28
|
Masi M, Pagès JM. Structure, Function and Regulation of Outer Membrane Proteins Involved in Drug Transport in Enterobactericeae: the OmpF/C - TolC Case. Open Microbiol J 2013; 7:22-33. [PMID: 23569467 PMCID: PMC3617542 DOI: 10.2174/1874285801307010022] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 02/01/2013] [Accepted: 02/03/2013] [Indexed: 11/26/2022] Open
Abstract
Antibiotic translocation across membranes of Gram-negative bacteria is a key step for the activity on their specific intracellular targets. Resistant bacteria control their membrane permeability as a first line of defense to protect themselves against external toxic compounds such as antibiotics and biocides. On one hand, resistance to small hydrophilic antibiotics such as ß-lactams and fluoroquinolones frequently results from the « closing » of their way in: the general outer membrane porins. On the other hand, an effective way out for a wide range of antibiotics is provided by TolC-like proteins, which are outer membrane components of multidrug efflux pumps. Accordingly, altered membrane permeability, including porin modifications and/or efflux pumps’ overexpression, is always associated to multidrug resistance (MDR) in a number of clinical isolates. Several recent studies have highlighted our current understanding of porins/TolC structures and functions in Enterobacteriaceae. Here, we review the transport of antibiotics through the OmpF/C general porins and the TolC-like channels with regards to recent data on their structure, function, assembly, regulation and contribution to bacterial resistance. Because MDR strains have evolved global strategies to identify and fight our antibiotic arsenal, it is important to constantly update our global knowledge on antibiotic transport.
Collapse
Affiliation(s)
- Muriel Masi
- CNRS-UMR 8619, Institut de Biophysique et de Biochimie Moléculaire et Cellulaire (IBBMC), Université Paris Sud, Orsay, France
| | | |
Collapse
|
29
|
Involvement of MarR and YedS in carbapenem resistance in a clinical isolate of Escherichia coli from China. Antimicrob Agents Chemother 2013; 57:1935-7. [PMID: 23318808 DOI: 10.1128/aac.02445-12] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A carbapenem-resistant clinical isolate of Escherichia coli, which lacked OmpF and OmpC porins, carried a marR mutation and expressed a functional yedS, a normally nontranslated gene. MarR and YedS are described here as having effects on the ability of this strain to resist carbapenems. Additionally, expression of YedS was regulated by the small RNA MicF in a MarA-dependent way. These findings illustrate how broadly bacteria can mutate within a selective clinical setting, in this case, resistance to carbapenems, by altering three porin genes and one regulatory gene.
Collapse
|
30
|
Transcriptional cross talk within the mar-sox-rob regulon in Escherichia coli is limited to the rob and marRAB operons. J Bacteriol 2012; 194:4867-75. [PMID: 22753060 DOI: 10.1128/jb.00680-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Bacteria possess multiple mechanisms to survive exposure to various chemical stresses and antimicrobial compounds. In the enteric bacterium Escherichia coli, three homologous transcription factors-MarA, SoxS, and Rob-play a central role in coordinating this response. Three separate systems are known to regulate the expression and activities of MarA, SoxS, and Rob. However, a number of studies have shown that the three do not function in isolation but rather are coregulated through transcriptional cross talk. In this work, we systematically investigated the extent of transcriptional cross talk in the mar-sox-rob regulon. While the three transcription factors were found to have the potential to regulate each other's expression when ectopically expressed, the only significant interactions observed under physiological conditions were between mar and rob systems. MarA, SoxS, and Rob all activate the marRAB promoter, more so when they are induced by their respective inducers: salicylate, paraquat, and decanoate. None of the three proteins affects the soxS promoter, though unexpectedly, it was mildly repressed by decanoate by an unknown mechanism. SoxS is the only one of the three proteins to repress the rob promoter. Surprisingly, salicylate somewhat activates transcription of rob, while decanoate represses it a bit. Rob, in turn, activates not only its downstream promoters in response to salicylate but also the marRAB promoter. These results demonstrate that the mar and rob systems function together in response to salicylate.
Collapse
|
31
|
Vila J, Soto SM. Salicylate increases the expression of marA and reduces in vitro biofilm formation in uropathogenic Escherichia coli by decreasing type 1 fimbriae expression. Virulence 2012; 3:280-5. [PMID: 22546909 DOI: 10.4161/viru.19205] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Escherichia coli is one of the most frequent bacteria implicated in biofilm formation, which is a dynamic process whose first step consists in bacteria adhesion to surfaces through type 1 fimbriae. Salicylate induces a number of morphological and physiological alterations in bacteria including the activation of the transcriptional regulator MarA. In this report the effects of salicylate on biofilm formation and their relationship with MarA were studied. An inverse relationship was observed between in vitro biofilm formation and salicylate concentration added to the culture medium. Salicylate increases the expression of marA and decreases the expression of fimA and fimB genes in the wild-type strain. In addition, the fimA and fimB expression was decreased in a MarR mutant in which marA was also overexpressed. In conclusion, the expression of type 1 fimbriae in presence of salicylate may be regulated by the level of marA expression through fimB regulator, albeit through neither the ompX nor the tolC genes.
Collapse
Affiliation(s)
- Jordi Vila
- Barcelona Centre for International Health Research, CRESIB, Hospital Clinic-University of Barcelona, Barcelona, Spain
| | | |
Collapse
|
32
|
Zgurskaya HI, Krishnamoorthy G, Ntreh A, Lu S. Mechanism and Function of the Outer Membrane Channel TolC in Multidrug Resistance and Physiology of Enterobacteria. Front Microbiol 2011; 2:189. [PMID: 21954395 PMCID: PMC3174397 DOI: 10.3389/fmicb.2011.00189] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 08/25/2011] [Indexed: 01/18/2023] Open
Abstract
TolC is an archetypal member of the outer membrane efflux protein (OEP) family. These proteins are involved in export of small molecules and toxins across the outer membrane of Gram-negative bacteria. Genomes of some bacteria such as Pseudomonas species contain multiple copies of OEPs. In contrast, enterobacteria contain a single tolC gene, the product of which functions with multiple transporters. Inactivation of tolC has a major impact on enterobacterial physiology and virulence. Recent studies suggest that the role of TolC in physiology of enterobacteria is very broad and affects almost all aspects of cell adaptation to adverse environments. We review the current state of understanding TolC structure and present an integrated view of TolC function in enterobacteria. We propose that seemingly unrelated phenotypes of tolC mutants are linked together by a single most common condition – an oxidative damage to membranes.
Collapse
Affiliation(s)
- Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma Norman, OK, USA
| | | | | | | |
Collapse
|
33
|
Whitehead RN, Overton TW, Kemp CL, Webber MA. Exposure of Salmonella enterica serovar Typhimurium to high level biocide challenge can select multidrug resistant mutants in a single step. PLoS One 2011; 6:e22833. [PMID: 21829527 PMCID: PMC3146503 DOI: 10.1371/journal.pone.0022833] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 06/29/2011] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Biocides are crucial to the prevention of infection by bacteria, particularly with the global emergence of multiply antibiotic resistant strains of many species. Concern has been raised regarding the potential for biocide exposure to select for antibiotic resistance due to common mechanisms of resistance, notably efflux. METHODOLOGY/PRINCIPAL FINDINGS Salmonella enterica serovar Typhimurium was challenged with 4 biocides of differing modes of action at both low and recommended-use concentration. Flow cytometry was used to investigate the physiological state of the cells after biocide challenge. After 5 hours exposure to biocide, live cells were sorted by FACS and recovered. Cells recovered after an exposure to low concentrations of biocide had antibiotic resistance profiles similar to wild-type cells. Live cells were recovered after exposure to two of the biocides at in-use concentration for 5 hours. These cells were multi-drug resistant and accumulation assays demonstrated an efflux phenotype of these mutants. Gene expression analysis showed that the AcrEF multidrug efflux pump was de-repressed in mutants isolated from high-levels of biocide. CONCLUSIONS/SIGNIFICANCE These data show that a single exposure to the working concentration of certain biocides can select for mutant Salmonella with efflux mediated multidrug resistance and that flow cytometry is a sensitive tool for identifying biocide tolerant mutants. The propensity for biocides to select for MDR mutants varies and this should be a consideration when designing new biocidal formulations.
Collapse
Affiliation(s)
- Rebekah N. Whitehead
- Antimicrobial Agents Research Group, School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom
- * E-mail: (MAW); (RNW)
| | - Tim W. Overton
- Biochemical Engineering, School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom
| | - Caroline L. Kemp
- Antimicrobial Agents Research Group, School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Mark A. Webber
- Antimicrobial Agents Research Group, School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom
- * E-mail: (MAW); (RNW)
| |
Collapse
|