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Rodríguez-Díaz M, Pérez FE, Manosalva PM, Cerda JI, Martínez-Contreras CF, Mora AY, Villagra NA, Bucarey SA, Barriga A, Escobar J, Martínez JL, Hidalgo AA. Antimicrobial Activity and Phytochemical Characterization of Baccharis concava Pers., a Native Plant of the Central Chilean Coast. Molecules 2024; 29:1654. [PMID: 38611933 PMCID: PMC11013932 DOI: 10.3390/molecules29071654] [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: 01/28/2024] [Revised: 03/22/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Few sclerophyllous plants from the central coast of Chile have been systematically studied. This work describes the phytochemical composition and antimicrobial properties of Baccharis concava Pers. (sin. B. macraei), a shrub found in the first line and near the Pacific coast. B. concava has been traditionally used by indigenous inhabitants of today's central Chile for its medicinal properties. Few reports exist regarding the phytochemistry characterization and biological activities of B. concava. A hydroalcoholic extract of B. concava was prepared from leaves and small branches. Qualitative phytochemical characterization indicated the presence of alkaloids, steroids, terpenoids, flavonoids, phenolic, and tannin compounds. The antimicrobial activity of this extract was assessed in a panel of microorganisms including Gram-positive bacteria, Gram-negative bacteria, and pathogenic yeasts. The extract displayed an important antimicrobial effect against Gram-positive bacteria, Candida albicans, and Cryptococcus neoformans but not against Gram-negatives, for which an intact Lipopolysaccharide is apparently the determinant of resistance to B. concava extracts. The hydroalcoholic extract was then fractionated through a Sephadex LH-20/methanol-ethyl acetate column. Afterward, the fractions were pooled according to a similar pattern visualized by TLC/UV analysis. Fractions obtained by this criterion were assessed for their antimicrobial activity against Staphylococcus aureus. The fraction presenting the most antimicrobial activity was HPLC-ESI-MS/MS, obtaining molecules related to caffeoylquinic acid, dicaffeoylquinic acid, and quercetin, among others. In conclusion, the extracts of B. concava showed strong antimicrobial activity, probably due to the presence of metabolites derived from phenolic acids, such as caffeoylquinic acid, and flavonoids, such as quercetin, which in turn could be responsible for helping with wound healing. In addition, the development of antimicrobial therapies based on the molecules found in B. concava could help to combat infection caused by pathogenic yeasts and Gram-positive bacteria, without affecting the Gram-negative microbiota.
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Affiliation(s)
- Maité Rodríguez-Díaz
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago 8370134, Chile; (M.R.-D.); (F.E.P.); (P.M.M.); (J.I.C.); (C.F.M.-C.)
| | - Fabián E. Pérez
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago 8370134, Chile; (M.R.-D.); (F.E.P.); (P.M.M.); (J.I.C.); (C.F.M.-C.)
| | - Paloma M. Manosalva
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago 8370134, Chile; (M.R.-D.); (F.E.P.); (P.M.M.); (J.I.C.); (C.F.M.-C.)
| | - Juan I. Cerda
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago 8370134, Chile; (M.R.-D.); (F.E.P.); (P.M.M.); (J.I.C.); (C.F.M.-C.)
| | - Consuelo F. Martínez-Contreras
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago 8370134, Chile; (M.R.-D.); (F.E.P.); (P.M.M.); (J.I.C.); (C.F.M.-C.)
| | - Aracely Y. Mora
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago 8380492, Chile;
| | - Nicolás A. Villagra
- Escuela de Tecnología Médica, Facultad de Salud, Universidad Santo Tomas, Santiago 8370003, Chile;
| | - Sergio A. Bucarey
- Departamento de Ciencias Biológicas, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile;
| | - Andrés Barriga
- Centro de Estudios Para el Desarrollo de la Química (CEPEDEQ), Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago 8380492, Chile;
| | - Jorge Escobar
- Laboratorio de Química Biológica, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 2340000, Chile
| | - José L. Martínez
- Departamento de Ingeniería Metalúrgica, Facultad de Ingeniería, Universidad de Santiago de Chile, Estación Central, Santiago 9160000, Chile
| | - Alejandro A. Hidalgo
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago 8370134, Chile; (M.R.-D.); (F.E.P.); (P.M.M.); (J.I.C.); (C.F.M.-C.)
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2
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Akshay SD, Deekshit VK, Mohan Raj J, Maiti B. Outer Membrane Proteins and Efflux Pumps Mediated Multi-Drug Resistance in Salmonella: Rising Threat to Antimicrobial Therapy. ACS Infect Dis 2023; 9:2072-2092. [PMID: 37910638 DOI: 10.1021/acsinfecdis.3c00408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Despite colossal achievements in antibiotic therapy in recent decades, drug-resistant pathogens have remained a leading cause of death and economic loss globally. One such WHO-critical group pathogen is Salmonella. The extensive and inappropriate treatments for Salmonella infections have led from multi-drug resistance (MDR) to extensive drug resistance (XDR). The synergy between efflux-mediated systems and outer membrane proteins (OMPs) may favor MDR in Salmonella. Differential expression of the efflux system and OMPs (influx) and positional mutations are the factors that can be correlated to the development of drug resistance. Insights into the mechanism of influx and efflux of antibiotics can aid in developing a structurally stable molecule that can be proficient at escaping from the resistance loops in Salmonella. Understanding the strategic responsibilities and developing policies to address the surge of drug resistance at the national, regional, and global levels are the needs of the hour. In this Review, we attempt to aggregate all the available research findings and delineate the resistance mechanisms by dissecting the involvement of OMPs and efflux systems. Integrating major OMPs and the efflux system's differential expression and positional mutation in Salmonella may provide insight into developing strategic therapies for one health application.
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Affiliation(s)
- Sadanand Dangari Akshay
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research, Department of Bio & Nano Technology, Paneer Campus, Deralakatte, Mangalore-575018, India
| | - Vijaya Kumar Deekshit
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research, Department of Infectious Diseases & Microbial Genomics, Paneer Campus, Deralakatte, Mangalore-575018, India
| | - Juliet Mohan Raj
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research, Department of Infectious Diseases & Microbial Genomics, Paneer Campus, Deralakatte, Mangalore-575018, India
| | - Biswajit Maiti
- Nitte (Deemed to be University), Nitte University Centre for Science Education and Research, Department of Bio & Nano Technology, Paneer Campus, Deralakatte, Mangalore-575018, India
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3
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Li Y, Ge X. Role of Berberine as a Potential Efflux Pump Inhibitor against MdfA from Escherichia coli: In Vitro and In Silico Studies. Microbiol Spectr 2023; 11:e0332422. [PMID: 36786641 PMCID: PMC10100983 DOI: 10.1128/spectrum.03324-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 01/30/2023] [Indexed: 02/15/2023] Open
Abstract
Infections by Gram-negative pathogens are usually difficult to manage due to the drug export by efflux pumps. With the evolution and horizontal transfer of efflux pumps, there is an urgent need to discover safe and effective efflux pump inhibitors. Here, we found that the natural compound berberine (BBR), a traditional medicine for intestinal infection, is an inhibitor against the major facilitator superfamily (MFS) efflux pump MdfA in Escherichia coli. The impact of BBR on MdfA was evaluated in a recombinant E. coli reporter strain. We demonstrated that low levels of BBR significantly increased intracellular ciprofloxacin concentrations and restored antibiotic susceptibility of the reporter strain. At the same time, we conducted molecular dynamics simulations to investigate the mechanisms of BBR's effect on MdfA. Our data indicated that BBR can aggregate to the periplasmic and cytoplasmic sides of MdfA in both of its inward and outward conformations. Protein rigidities were affected to different degrees. More importantly, two major driving forces for the conformational transition, salt bridges and hydrophilic interactions with water, were changed by BBR's aggregation to MdfA, which affected its conformational transition. In summary, our data provide evidence for the extended application of BBR as an efflux pump inhibitor at a clinically meaningful level. We also reveal the mechanisms and provide insights into BBR's effect on the reciprocal motion of MdfA. IMPORTANCE In this work, we evaluated the role of berberine (BBR) as an inhibitor of the MFS efflux pump MdfA from E. coli. We demonstrated that low levels of BBR significantly increased intracellular ciprofloxacin concentrations and restored antibiotic susceptibility of the reporter strain. Molecular dynamics simulations revealed the effect of BBR on the conformational transition of MdfA. Our data suggested that driving forces for MdfA's conformational transition were affected by BBR and provided evidence for BBR's extended application as an effective inhibitor of MdfA.
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Affiliation(s)
- Ying Li
- College of Biochemical Engineering, Beijing Union University, Beijing, China
| | - Xizhen Ge
- College of Biochemical Engineering, Beijing Union University, Beijing, China
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4
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Holden ER, Yasir M, Turner AK, Wain J, Charles IG, Webber MA. Genome-wide analysis of genes involved in efflux function and regulation within Escherichia coli and Salmonella enterica serovar Typhimurium. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36745554 DOI: 10.1099/mic.0.001296] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The incidence of multidrug-resistant bacteria is increasing globally, with efflux pumps being a fundamental platform limiting drug access and synergizing with other mechanisms of resistance. Increased expression of efflux pumps is a key feature of most cells that are resistant to multiple antibiotics. Whilst expression of efflux genes can confer benefits, production of complex efflux systems is energetically costly and the expression of efflux is highly regulated, with cells balancing benefits against costs. This study used TraDIS-Xpress, a genome-wide transposon mutagenesis technology, to identify genes in Escherichia coli and Salmonella Typhimurium involved in drug efflux and its regulation. We exposed mutant libraries to the canonical efflux substrate acriflavine in the presence and absence of the efflux inhibitor phenylalanine-arginine β-naphthylamide. Comparisons between conditions identified efflux-specific and drug-specific responses. Known efflux-associated genes were easily identified, including acrAB, tolC, marRA, ramRA and soxRS, confirming the specificity of the response. Further genes encoding cell envelope maintenance enzymes and products involved with stringent response activation, DNA housekeeping, respiration and glutathione biosynthesis were also identified as affecting efflux activity in both species. This demonstrates the deep relationship between efflux regulation and other cellular regulatory networks. We identified a conserved set of pathways crucial for efflux activity in these experimental conditions, which expands the list of genes known to impact on efflux efficacy. Responses in both species were similar and we propose that these common results represent a core set of genes likely to be relevant to efflux control across the Enterobacteriaceae.
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Affiliation(s)
- Emma R Holden
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - Muhammad Yasir
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - A Keith Turner
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - John Wain
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK.,Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Ian G Charles
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK.,Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Mark A Webber
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK.,Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
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5
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Li Y, Ge X. Molecular Dynamics Investigation of MFS Efflux Pump MdfA Reveals an Intermediate State between Its Inward and Outward Conformations. Int J Mol Sci 2022; 24:ijms24010356. [PMID: 36613823 PMCID: PMC9820426 DOI: 10.3390/ijms24010356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Multidrug resistance poses a major challenge to antibiotic therapy. A principal cause of antibiotic resistance is through active export by efflux pumps embedded in the bacterial membrane. Major facilitator superfamily (MFS) efflux pumps constitute a major group of transporters, which are often related to quinolone resistance in clinical settings. Although a rocker-switch model is proposed for description of their conformational transitions, detailed changes in this process remain poorly understood. Here we used MdfA from E. coli as a representative MFS efflux pump to investigate factors that can affect its conformational transition in silico. Molecular dynamics (MD) simulations of MdfA's inward and outward conformations revealed an intermediate state between these two conformations. By comparison of the subtle differences between the intermediate state and the average state, we indicated that conformational transition from outward to inward was initiated by protonation of the periplasmic side. Subsequently, hydrophilic interaction of the periplasmic side with water was promoted and the regional structure of helix 1 was altered to favor this process. As the hydrophobic interaction between MdfA and membrane was also increased, energy was concentrated and stored for the opposite transition. In parallel, salt bridges at the cytoplasmic side were altered to lower probabilities to facilitate the entrance of substrate. In summary, we described the total and local changes during MdfA's conformational transition, providing insights for the development of potential inhibitors.
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Affiliation(s)
| | - Xizhen Ge
- Correspondence: ; Tel.: +86-10-5207-2337
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6
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Wand ME, Sutton JM. Efflux-mediated tolerance to cationic biocides, a cause for concern? MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36748532 DOI: 10.1099/mic.0.001263] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
AbstractWith an increase in the number of isolates resistant to multiple antibiotics, infection control has become increasingly important to help combat the spread of multi-drug-resistant pathogens. An important component of this is through the use of disinfectants and antiseptics (biocides). Antibiotic resistance has been well studied in bacteria, but little is known about potential biocide resistance genes and there have been few reported outbreaks in hospitals resulting from a breakdown in biocide effectiveness. Development of increased tolerance to biocides has been thought to be more difficult due to the mode of action of biocides which affect multiple cellular targets compared with antibiotics. Very few genes which contribute towards increased biocide tolerance have been identified. However, the majority of those that have are components or regulators of different efflux pumps or genes which modulate membrane function/modification. This review will examine the role of efflux in increased tolerance towards biocides, focusing on cationic biocides and heavy metals against Gram-negative bacteria. As many efflux pumps which are upregulated by biocide presence also contribute towards an antimicrobial resistance phenotype, the role of these efflux pumps in cross-resistance to both other biocides and antibiotics will be explored.
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Affiliation(s)
- Matthew E Wand
- Technology Development Group, UK Health Security Agency, Research and Evaluation, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| | - J Mark Sutton
- Technology Development Group, UK Health Security Agency, Research and Evaluation, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
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7
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Functional Role of YnfA, an Efflux Transporter in Resistance to Antimicrobial Agents in Shigella flexneri. Antimicrob Agents Chemother 2022; 66:e0029322. [PMID: 35727058 PMCID: PMC9295541 DOI: 10.1128/aac.00293-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shigella flexneri has become a significant public health concern accounting for the majority of shigellosis cases worldwide. Even though a multitude of efforts is being made into the development of a vaccine to prevent infections, the absence of a licensed global vaccine compels us to enormously depend on antibiotics as the major treatment option. The extensive-unregulated use of antibiotics for treatment along with natural selection in bacteria has led to the rising of multidrug-resistance Shigella strains. Out of the various mechanisms employed by bacteria to gain resistance, efflux transporters are considered to be one of the principal contributors to antimicrobial resistance. The small multidrug-resistance family consists of unique small proteins that act as efflux pumps and are involved in extruding various antimicrobial compounds. The present study aims to demonstrate the role of an efflux transporter YnfA belonging to the SMR family and its functional involvement in promoting antimicrobial resistance in S. flexneri. Employing various genetic, computational, and biochemical techniques, we show how disrupting the YnfA transporter, renders the mutant Shigella strain more susceptible to some antimicrobial compounds tested in this study, and significantly affects the overall transport activity of the bacteria against ethidium bromide and acriflavine when compared with the wild-type Shigella strain. We also assessed how mutating some of the conserved amino acid residues of YnfA alters the resistance profile and efflux activity of the mutant YnfA transporter. This study provides a functional understanding of an uncharacterized SMR transporter YnfA of Shigella.
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8
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Nishino K, Yamasaki S, Nakashima R, Zwama M, Hayashi-Nishino M. Function and Inhibitory Mechanisms of Multidrug Efflux Pumps. Front Microbiol 2021; 12:737288. [PMID: 34925258 PMCID: PMC8678522 DOI: 10.3389/fmicb.2021.737288] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/14/2021] [Indexed: 12/31/2022] Open
Abstract
Multidrug efflux pumps are inner membrane transporters that export multiple antibiotics from the inside to the outside of bacterial cells, contributing to bacterial multidrug resistance (MDR). Postgenomic analysis has demonstrated that numerous multidrug efflux pumps exist in bacteria. Also, the co-crystal structural analysis of multidrug efflux pumps revealed the drug recognition and export mechanisms, and the inhibitory mechanisms of the pumps. A single multidrug efflux pump can export multiple antibiotics; hence, developing efflux pump inhibitors is crucial in overcoming infectious diseases caused by multidrug-resistant bacteria. This review article describes the role of multidrug efflux pumps in MDR, and their physiological functions and inhibitory mechanisms.
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Affiliation(s)
- Kunihiko Nishino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Osaka, Japan
| | - Seiji Yamasaki
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Osaka, Japan
| | - Ryosuke Nakashima
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Osaka, Japan
| | - Martijn Zwama
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Osaka, Japan
| | - Mitsuko Hayashi-Nishino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Osaka, Japan
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9
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Short FL, Liu Q, Shah B, Clift HE, Naidu V, Li L, Prity FT, Mabbutt BC, Hassan KA, Paulsen IT. The Acinetobacter baumannii disinfectant resistance protein, AmvA, is a spermidine and spermine efflux pump. Commun Biol 2021; 4:1114. [PMID: 34552198 PMCID: PMC8458285 DOI: 10.1038/s42003-021-02629-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 09/01/2021] [Indexed: 02/08/2023] Open
Abstract
Antimicrobial resistance genes, including multidrug efflux pumps, evolved long before the ubiquitous use of antimicrobials in medicine and infection control. Multidrug efflux pumps often transport metabolites, signals and host-derived molecules in addition to antibiotics or biocides. Understanding their ancestral physiological roles could inform the development of strategies to subvert their activity. In this study, we investigated the response of Acinetobacter baumannii to polyamines, a widespread, abundant class of amino acid-derived metabolites, which led us to identify long-chain polyamines as natural substrates of the disinfectant efflux pump AmvA. Loss of amvA dramatically reduced tolerance to long-chain polyamines, and these molecules induce expression of amvA through binding to its cognate regulator AmvR. A second clinically-important efflux pump, AdeABC, also contributed to polyamine tolerance. Our results suggest that the disinfectant resistance capability that allows A. baumannii to survive in hospitals may have evolutionary origins in the transport of polyamine metabolites.
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Affiliation(s)
- Francesca L. Short
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia ,grid.1002.30000 0004 1936 7857Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC Australia
| | - Qi Liu
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia
| | - Bhumika Shah
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia
| | - Heather E. Clift
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia ,grid.280427.b0000 0004 0434 015XPresent Address: Versiti Blood Research Institute, Milwaukee, WI USA
| | - Varsha Naidu
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia
| | - Liping Li
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia
| | - Farzana T. Prity
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia
| | - Bridget C. Mabbutt
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia
| | - Karl A. Hassan
- grid.266842.c0000 0000 8831 109XSchool of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW Australia
| | - Ian T. Paulsen
- grid.1004.50000 0001 2158 5405Department of Molecular Sciences, Macquarie University, North Ryde, NSW Australia
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10
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Han S, Ferelli AMC, Lin SS, Micallef SA. Stress response, amino acid biosynthesis and pathogenesis genes expressed in Salmonella enterica colonizing tomato shoot and root surfaces. Heliyon 2020; 6:e04952. [PMID: 33024855 PMCID: PMC7527575 DOI: 10.1016/j.heliyon.2020.e04952] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/13/2020] [Accepted: 09/11/2020] [Indexed: 01/08/2023] Open
Abstract
Salmonella enterica can colonize all parts of the tomato plant. Tomatoes have been frequently implicated in salmonellosis outbreaks. In agricultural settings, Salmonella must overcome stress, nutritional and competition barriers to become established on plant surfaces. Knowledge of the genetic mechanisms underlying Salmonella-plant associations is limited, especially when growing epiphytically. A genome-wide transcriptomic analysis of Salmonella Typhimurium (SeT) was conducted with RNA-Seq to elucidate strategies for epiphytic growth on live, intact tomato shoot and root surfaces. Six plasmid-encoded and 123 chromosomal genes were significantly (using Benjamini-Hochberg adjusted p-values) up-regulated; 54 and 110 detected in SeT on shoots and roots, respectively, with 35 common to both. Key signals included NsrR regulon genes needed to mitigate nitrosative stress, oxidative stress genes and host adaptation genes, including environmental stress, heat shock and acid-inducible genes. Several amino acid biosynthesis genes and genes indicative of sulphur metabolism and anaerobic respiration were up-regulated. Some Type III secretion system (T3SS) effector protein genes and their chaperones from pathogenicity island-2 were expressed mostly in SeT on roots. Gene expression in SeT was validated against SeT and also the tomato outbreak strain Salmonella Newport with a high correlation (R 2 = 0.813 and 0.874, respectively; both p < 0.001). Oxidative and nitrosative stress response genes, T3SS2 genes and amino acid biosynthesis may be needed for Salmonella to successfully colonize tomato shoot and root surfaces.
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Affiliation(s)
- Sanghyun Han
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland, USA
| | - Angela Marie C Ferelli
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland, USA
| | - Shih-Shun Lin
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Shirley A Micallef
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland, USA.,Centre for Food Safety and Security Systems, University of Maryland, College Park, Maryland, USA
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11
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Impey RE, Hawkins DA, Sutton JM, Soares da Costa TP. Overcoming Intrinsic and Acquired Resistance Mechanisms Associated with the Cell Wall of Gram-Negative Bacteria. Antibiotics (Basel) 2020; 9:E623. [PMID: 32961699 PMCID: PMC7558195 DOI: 10.3390/antibiotics9090623] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 12/19/2022] Open
Abstract
The global increase in multi-drug-resistant bacteria is severely impacting our ability to effectively treat common infections. For Gram-negative bacteria, their intrinsic and acquired resistance mechanisms are heightened by their unique cell wall structure. The cell wall, while being a target of some antibiotics, represents a barrier due to the inability of most antibacterial compounds to traverse and reach their intended target. This means that its composition and resulting mechanisms of resistance must be considered when developing new therapies. Here, we discuss potential antibiotic targets within the most well-characterised resistance mechanisms associated with the cell wall in Gram-negative bacteria, including the outer membrane structure, porins and efflux pumps. We also provide a timely update on the current progress of inhibitor development in these areas. Such compounds could represent new avenues for drug discovery as well as adjuvant therapy to help us overcome antibiotic resistance.
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Affiliation(s)
- Rachael E. Impey
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
| | - Daniel A. Hawkins
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
| | - J. Mark Sutton
- National Infection Service, Research and Development Institute, Public Health England, Porton Down, Salisbury, Wiltshire SP4 0JG, UK;
| | - Tatiana P. Soares da Costa
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
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12
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Ashrafudoulla M, Mizan MFR, Park SH, Ha SD. Current and future perspectives for controlling Vibrio biofilms in the seafood industry: a comprehensive review. Crit Rev Food Sci Nutr 2020; 61:1827-1851. [PMID: 32436440 DOI: 10.1080/10408398.2020.1767031] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The contamination of seafood with Vibrio species can have severe repercussions in the seafood industry. Vibrio species can form mature biofilms and persist on the surface of several seafoods such as crabs, oysters, mussels, and shrimp, for extended duration. Several conventional approaches have been employed to inhibit the growth of planktonic cells and prevent the formation of Vibrio biofilms. Since Vibrio biofilms are mostly resistant to these control measures, novel alternative methods need to be urgently developed. In this review, we propose environmentally friendly approaches to suppress Vibrio biofilm formation using a hypothesized mechanism of action.
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Affiliation(s)
- Md Ashrafudoulla
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Anseong, Gyunggi-do, Republic of Korea
| | - Md Furkanur Rahaman Mizan
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Anseong, Gyunggi-do, Republic of Korea
| | - Si Hong Park
- Food Science and Technology, Oregon State University, Corvallis, Oregon, USA
| | - Sang-Do Ha
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Anseong, Gyunggi-do, Republic of Korea
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13
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Yamagishi A, Nakano S, Yamasaki S, Nishino K. An efflux inhibitor of the MacAB pump in Salmonella enterica serovar Typhimurium. Microbiol Immunol 2020; 64:182-188. [PMID: 31825103 DOI: 10.1111/1348-0421.12765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/26/2019] [Accepted: 12/01/2019] [Indexed: 12/13/2022]
Abstract
Multidrug efflux pumps play an important role in bacterial multidrug resistance by actively excreting antibiotics. The ATP-binding cassette-type drug efflux pump MacAB was originally reported as a macrolide-specific pump. MacAB is also known to be required for the virulence of Salmonella enterica serovar Typhimurium following oral infection in mice. Here, we performed a screening of inhibitors of Salmonella MacAB and found a compound that increased the susceptibility of a MacAB-expressing strain to macrolides. It was previously reported that MacAB is required to resist peroxide-mediated killing in vitro and that a supernatant of wild-type Salmonella rescues the growth defect of a macAB mutant in H2 O2 . In this study, we also found that the MacAB inhibitor reduced the ability of the supernatant to rescue Salmonella cells in H2 O2 . This compound could lead to a better understanding of the function of MacAB.
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Affiliation(s)
- Ami Yamagishi
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Sohei Nakano
- School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Seiji Yamasaki
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.,School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.,Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan.,Institute for Advanced Co-Creation Studies, Osaka University, Osaka, Japan
| | - Kunihiko Nishino
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.,School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.,Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
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14
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Pelling H, Bock LJ, Nzakizwanayo J, Wand ME, Denham EL, MacFarlane WM, Sutton JM, Jones BV. De-repression of the smvA efflux system arises in clinical isolates of Proteus mirabilis and reduces susceptibility to chlorhexidine and other biocides. Antimicrob Agents Chemother 2019; 63:AAC.01535-19. [PMID: 31570392 PMCID: PMC6879213 DOI: 10.1128/aac.01535-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/18/2019] [Indexed: 01/14/2023] Open
Abstract
Proteus mirabilis is a common pathogen of the catheterised urinary tract and often described as intrinsically resistant to the biocide chlorhexidine (CHD). Here we demonstrate that de-repression of the smvA efflux system has occurred in clinical isolates of P. mirabilis and reduces susceptibility to CHD and other cationic biocides. Compared to other isolates examined, P. mirabilis RS47 exhibited a significantly higher CHD MIC (≥512 μg/ml) and significantly greater expression of smvA. Comparison of the RS47 smvA and cognate smvR repressor with sequences from other isolates, indicated that RS47 encodes an inactivated smvR. Complementation of RS47 with a functional smvR from isolate RS50a (which exhibited the lowest smvA expression and lowest CHD MIC) reduced smvA expression by ∼59-fold, and markedly lowered the MIC of CHD and other cationic biocides. Although complementation of RS47 did not reduce MICs to concentrations observed in isolate RS50a, the significantly lower polymyxin B MIC of RS50a indicated that differences in LPS structure are also a factor in P. mirabilis CHD susceptibility. To determine if exposure to CHD can select for mutations in smvR, clinical isolates with the lowest CHD MICs were adapted to grow at increasing concentrations of CHD up to 512 μg/ml. Analysis of the smvR in adapted populations indicated that mutations predicted to inactivate smvR occurred following CHD exposure in some isolates. Collectively, our data show that smvA de-repression contributes to reduced biocide susceptibility in P. mirabilis, but differences in LPS structure between strains are also likely to be an important factor.
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Affiliation(s)
- H Pelling
- Dept. of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, BN2 4GJ, UK
| | - L J Bock
- National Infections Service, Public Health England, Porton Down, Salisbury, SP4 0JG, UK
| | - J Nzakizwanayo
- Dept. of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - M E Wand
- National Infections Service, Public Health England, Porton Down, Salisbury, SP4 0JG, UK
| | - E L Denham
- Dept. of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - W M MacFarlane
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, BN2 4GJ, UK
| | - J M Sutton
- National Infections Service, Public Health England, Porton Down, Salisbury, SP4 0JG, UK
| | - B V Jones
- Dept. of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
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15
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Villagra NA, Valenzuela LM, Mora AY, Millanao AR, Saavedra CP, Mora GC, Hidalgo AA. Cysteine auxotrophy drives reduced susceptibility to quinolones and paraquat by inducing the expression of efflux-pump systems and detoxifying enzymes in S. Typhimurium. Biochem Biophys Res Commun 2019; 515:339-344. [PMID: 31151825 DOI: 10.1016/j.bbrc.2019.05.122] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 05/19/2019] [Indexed: 12/15/2022]
Abstract
Currently, Salmonella enterica serovar Typhimurium (S. Typhimurium), is a major global public health problem, which has caused food-borne illnesses in many countries. Today, with the extensive use of antimicrobials, antimicrobial resistance is increasing at a serious rate in S. Typhimurium isolates. The present study sought the role of cysteine (Cys) auxotrophy on the resistance to quinolones and paraquat in S. Typhimurium. Cys auxotrophy was achieved by deleting either the cysDNC, cysJIH or cysQ loci. Deletion of these loci resulted in loss of susceptibility against nalidixic acid, levofloxacin, ciprofloxacin (CIP) and paraquat. Further studies with cysJIH mutant indicated increased expression of multi-antibiotic resistance genes marA and ramA, and consequently increased expression of efflux-pump systems. The cysJIH mutant presented a smaller increase of reactive oxygen species (ROS) in presence of paraquat or CIP. Expression of katG and sodA (expressing for a catalase and a superoxide dismutase, respectively) genes was increased in presence of paraquat in the cysJIH mutant; while expression of the superoxide dismutase gene sodB was decreased. These results indicate that deletion of cysDNC, cysJIH or cysQ genes of S. Typhimurium renders Cys auxotrophy along with decreased susceptibility in response to quinolone and paraquat. Overexpression of efflux-pump systems AcrB-TolC and SmvA-OmpD and antioxidant enzymes KatG and SodA could explain the mechanisms of antimicrobial resistance in the Cys auxotrophic mutants.
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Affiliation(s)
| | | | - Aracely Y Mora
- Escuela de Química y Farmacia, Universidad Andres Bello, Santiago, Chile
| | - Ana R Millanao
- Escuela de Química y Farmacia, Universidad Andres Bello, Santiago, Chile; Instituto de Farmacia, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Claudia P Saavedra
- Laboratorio de Microbiología Molecular, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Guido C Mora
- Instituto de Investigación Interdisciplinar en Ciencias Biomédicas SEK (I3CBSEK), Facultad de Ciencias de la Salud, Universidad SEK, Santiago, Chile
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16
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Wand ME, Jamshidi S, Bock LJ, Rahman KM, Sutton JM. SmvA is an important efflux pump for cationic biocides in Klebsiella pneumoniae and other Enterobacteriaceae. Sci Rep 2019; 9:1344. [PMID: 30718598 PMCID: PMC6362122 DOI: 10.1038/s41598-018-37730-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 12/04/2018] [Indexed: 01/13/2023] Open
Abstract
The multidrug resistant (MDR) opportunistic pathogen Klebsiella pneumoniae has previously been shown to adapt to chlorhexidine by increasing expression of the MFS efflux pump smvA. Here we show that loss of the regulator SmvR, through adaptation to chlorhexidine, results in increased resistance to a number of cationic biocides in K. pneumoniae and other members of the Enterobacteriaceae. Clinical Enterobacteriaceae isolates which lack smvA and smvR also have an increased susceptibility to chlorhexidine. When smvA from Salmonella and K. pneumoniae are expressed in Escherichia coli, which lacks a homologue to SmvAR, resistance to chlorhexidine increased (4-fold) but plasmid carriage of smvA alone was detrimental to the cell. Challenge of K. pneumoniae with chlorhexidine and another cationic biocide, octenidine, resulted in increased expression of smvA (approx. 70 fold). Adaptation to octenidine was achieved through mutating key residues in SmvA (A363V; Y391N) rather than abolishing the function of SmvR, as with chlorhexidine adaptation. Molecular modelling was able to predict that octenidine interacted more strongly with these mutated SmvA forms. These results show that SmvA is a major efflux pump for cationic biocides in several bacterial species and that increased efflux through SmvA can lead to increased chlorhexidine and octenidine tolerance.
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Affiliation(s)
- Matthew E Wand
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK.
| | - Shirin Jamshidi
- School of Cancer and Pharmaceutical Science, King's College London, London, SE1 9NH, UK
| | - Lucy J Bock
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| | | | - J Mark Sutton
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
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17
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Slipski CJ, Zhanel GG, Bay DC. Biocide Selective TolC-Independent Efflux Pumps in Enterobacteriaceae. J Membr Biol 2018; 251:15-33. [PMID: 29063140 PMCID: PMC5840245 DOI: 10.1007/s00232-017-9992-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/04/2017] [Indexed: 02/03/2023]
Abstract
Bacterial resistance to biocides used as antiseptics, dyes, and disinfectants is a growing concern in food preparation, agricultural, consumer manufacturing, and health care industries, particularly among Gram-negative Enterobacteriaceae, some of the most common community and healthcare-acquired bacterial pathogens. Biocide resistance is frequently associated with antimicrobial cross-resistance leading to reduced activity and efficacy of both antimicrobials and antiseptics. Multidrug resistant efflux pumps represent an important biocide resistance mechanism in Enterobacteriaceae. An assortment of structurally diverse efflux pumps frequently co-exist in these species and confer both unique and overlapping biocide and antimicrobial selectivity. TolC-dependent multicomponent systems that span both the plasma and outer membranes have been shown to confer clinically significant resistance to most antimicrobials including many biocides, however, a growing number of single component TolC-independent multidrug resistant efflux pumps are specifically associated with biocide resistance: small multidrug resistance (SMR), major facilitator superfamily (MFS), multidrug and toxin extruder (MATE), cation diffusion facilitator (CDF), and proteobacterial antimicrobial compound efflux (PACE) families. These efflux systems are a growing concern as they are rapidly spread between members of Enterobacteriaceae on conjugative plasmids and mobile genetic elements, emphasizing their importance to antimicrobial resistance. In this review, we will summarize the known biocide substrates of these efflux pumps, compare their structural relatedness, Enterobacteriaceae distribution, and significance. Knowledge gaps will be highlighted in an effort to unravel the role that these apparent "lone wolves" of the efflux-mediated resistome may offer.
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Affiliation(s)
- Carmine J Slipski
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada
| | - George G Zhanel
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada
| | - Denice C Bay
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada.
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18
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Mechanisms of Increased Resistance to Chlorhexidine and Cross-Resistance to Colistin following Exposure of Klebsiella pneumoniae Clinical Isolates to Chlorhexidine. Antimicrob Agents Chemother 2016; 61:AAC.01162-16. [PMID: 27799211 DOI: 10.1128/aac.01162-16] [Citation(s) in RCA: 172] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 10/09/2016] [Indexed: 12/16/2022] Open
Abstract
Klebsiella pneumoniae is an opportunistic pathogen that is often difficult to treat due to its multidrug resistance (MDR). We have previously shown that K. pneumoniae strains are able to "adapt" (become more resistant) to the widely used bisbiguanide antiseptic chlorhexidine. Here, we investigated the mechanisms responsible for and the phenotypic consequences of chlorhexidine adaptation, with particular reference to antibiotic cross-resistance. In five of six strains, adaptation to chlorhexidine also led to resistance to the last-resort antibiotic colistin. Here, we show that chlorhexidine adaptation is associated with mutations in the two-component regulator phoPQ and a putative Tet repressor gene (smvR) adjacent to the major facilitator superfamily (MFS) efflux pump gene, smvA Upregulation of smvA (10- to 27-fold) was confirmed in smvR mutant strains, and this effect and the associated phenotype were suppressed when a wild-type copy of smvR was introduced on plasmid pACYC. Upregulation of phoPQ (5- to 15-fold) and phoPQ-regulated genes, pmrD (6- to 19-fold) and pmrK (18- to 64-fold), was confirmed in phoPQ mutant strains. In contrast, adaptation of K. pneumoniae to colistin did not result in increased chlorhexidine resistance despite the presence of mutations in phoQ and elevated phoPQ, pmrD, and pmrK transcript levels. Insertion of a plasmid containing phoPQ from chlorhexidine-adapted strains into wild-type K. pneumoniae resulted in elevated expression levels of phoPQ, pmrD, and pmrK and increased resistance to colistin, but not chlorhexidine. The potential risk of colistin resistance emerging in K. pneumoniae as a consequence of exposure to chlorhexidine has important clinical implications for infection prevention procedures.
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Ionic Liquids Impact the Bioenergy Feedstock-Degrading Microbiome and Transcription of Enzymes Relevant to Polysaccharide Hydrolysis. mSystems 2016; 1:mSystems00120-16. [PMID: 27981239 PMCID: PMC5155067 DOI: 10.1128/msystems.00120-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/15/2016] [Indexed: 01/12/2023] Open
Abstract
Pretreatment using ionic liquids (IL) is a promising approach for the conversion of lignocellulose to biofuels. Because IL can be inhibitory to enzymes and microorganisms involved in downstream hydrolysis and fermentation steps, discovery of IL-tolerant organisms and enzymes is critical for advancing this technology. Employing metatranscriptomics in the analysis of IL-enriched cultures facilitated tracking of dynamic changes in a complex microbial community at the level of gene transcription and doing so with genome resolution. Specific organisms were discovered that could simultaneously tolerate a moderate IL concentration and transcribe a diverse array of cellulolytic enzymes. Gene sequences of cellulolytic enzymes and efflux pumps from those same organisms were also identified, providing important resources for future research on engineering IL-tolerant organisms and enzymes. Ionic liquid (IL) pretreatment is a promising approach for the conversion of lignocellulose to biofuels. The toxicity of residual IL, however, negatively impacts the performance of industrial enzymes and microorganisms in hydrolysis and fermentation. In this study, a thermophilic microbial community was cultured on switchgrass amended with various levels of the ionic liquid 1-ethyl-3-methylimidazolium acetate. Changes in the microbial community composition and transcription of genes relevant to IL tolerance and lignocellulose hydrolysis were quantified. Increasing the level of IL to 0.1% (wt) led to increased levels of relative abundance and transcription in organisms of the phylum Firmicutes. Interestingly, IL concentrations of up to 1% (wt) also resulted in greater xylanase transcription and enzyme activity as well as increased transcription of endoglucanase, beta-glucosidase, and IL tolerance genes compared to communities without IL. IL levels above 1% (wt) resulted in decreased enzyme activity and transcription of genes involved in lignocellulose hydrolysis. The results indicate that moderate levels of IL select for thermophilic microorganisms that not only tolerate IL but also effectively hydrolyze lignocellulose from switchgrass. Discovery of IL-tolerant organisms and enzymes is critical for the development of biological processes that convert IL-pretreated biomass to biofuels and chemicals. Employing metatranscriptomic analysis of enrichment cultures can facilitate the discovery of microorganisms and enzymes that may be active in the presence of toxic compounds such as ionic liquids. IMPORTANCE Pretreatment using ionic liquids (IL) is a promising approach for the conversion of lignocellulose to biofuels. Because IL can be inhibitory to enzymes and microorganisms involved in downstream hydrolysis and fermentation steps, discovery of IL-tolerant organisms and enzymes is critical for advancing this technology. Employing metatranscriptomics in the analysis of IL-enriched cultures facilitated tracking of dynamic changes in a complex microbial community at the level of gene transcription and doing so with genome resolution. Specific organisms were discovered that could simultaneously tolerate a moderate IL concentration and transcribe a diverse array of cellulolytic enzymes. Gene sequences of cellulolytic enzymes and efflux pumps from those same organisms were also identified, providing important resources for future research on engineering IL-tolerant organisms and enzymes.
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Dulyayangkul P, Charoenlap N, Srijaruskul K, Mongkolsuk S, Vattanaviboon P. Major facilitator superfamily MfsA contributes to multidrug resistance in emerging nosocomial pathogenStenotrophomonas maltophilia: Table 1. J Antimicrob Chemother 2016; 71:2990-1. [DOI: 10.1093/jac/dkw233] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Blanco P, Hernando-Amado S, Reales-Calderon JA, Corona F, Lira F, Alcalde-Rico M, Bernardini A, Sanchez MB, Martinez JL. Bacterial Multidrug Efflux Pumps: Much More Than Antibiotic Resistance Determinants. Microorganisms 2016; 4:microorganisms4010014. [PMID: 27681908 PMCID: PMC5029519 DOI: 10.3390/microorganisms4010014] [Citation(s) in RCA: 361] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/22/2016] [Accepted: 01/29/2016] [Indexed: 02/07/2023] Open
Abstract
Bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. With few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. In addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. Altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibiotics for human and animal therapy. In this regard, it is worth mentioning that efflux pumps can extrude a wide range of substrates that include, besides antibiotics, heavy metals, organic pollutants, plant-produced compounds, quorum sensing signals or bacterial metabolites, among others. In the current review, we present information on the different functions that multidrug efflux pumps may have for the bacterial behaviour in different habitats as well as on their regulation by specific signals. Since, in addition to their function in non-clinical ecosystems, multidrug efflux pumps contribute to intrinsic, acquired, and phenotypic resistance of bacterial pathogens, the review also presents information on the search for inhibitors of multidrug efflux pumps, which are currently under development, in the aim of increasing the susceptibility of bacterial pathogens to antibiotics.
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Affiliation(s)
- Paula Blanco
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
| | - Sara Hernando-Amado
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
| | - Jose Antonio Reales-Calderon
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
| | - Fernando Corona
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
| | - Felipe Lira
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
| | - Manuel Alcalde-Rico
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
| | - Alejandra Bernardini
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
| | - Maria Blanca Sanchez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
| | - Jose Luis Martinez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
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22
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Srinivasan VB, Singh BB, Priyadarshi N, Chauhan NK, Rajamohan G. Role of novel multidrug efflux pump involved in drug resistance in Klebsiella pneumoniae. PLoS One 2014; 9:e96288. [PMID: 24823362 PMCID: PMC4019481 DOI: 10.1371/journal.pone.0096288] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 04/06/2014] [Indexed: 12/02/2022] Open
Abstract
Background Multidrug resistant Klebsiella pneumoniae have caused major therapeutic problems worldwide due to the emergence of the extended-spectrum β-lactamase producing strains. Although there are >10 major facilitator super family (MFS) efflux pumps annotated in the genome sequence of the K. pneumoniae bacillus, apparently less is known about their physiological relevance. Principal Findings Insertional inactivation of kpnGH resulting in increased susceptibility to antibiotics such as azithromycin, ceftazidime, ciprofloxacin, ertapenem, erythromycin, gentamicin, imipenem, ticarcillin, norfloxacin, polymyxin-B, piperacillin, spectinomycin, tobramycin and streptomycin, including dyes and detergents such as ethidium bromide, acriflavine, deoxycholate, sodium dodecyl sulphate, and disinfectants benzalkonium chloride, chlorhexidine and triclosan signifies the wide substrate specificity of the transporter in K. pneumoniae. Growth inactivation and direct fluorimetric efflux assays provide evidence that kpnGH mediates antimicrobial resistance by active extrusion in K. pneumoniae. The kpnGH isogenic mutant displayed decreased tolerance to cell envelope stressors emphasizing its added role in K. pneumoniae physiology. Conclusions and Significance The MFS efflux pump KpnGH involves in crucial physiological functions besides being an intrinsic resistance determinant in K. pneumoniae.
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Affiliation(s)
- Vijaya Bharathi Srinivasan
- Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India
| | - Bharat Bhushan Singh
- Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India
| | - Nitesh Priyadarshi
- Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India
| | - Neeraj Kumar Chauhan
- Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India
| | - Govindan Rajamohan
- Bacterial signaling and Drug Resistance Laboratory, Council of Scientific Industrial Research- Institute of Microbial Technology, Chandigarh, India
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Outer membrane protein OmpW participates with small multidrug resistance protein member EmrE in quaternary cationic compound efflux. J Bacteriol 2014; 196:1908-14. [PMID: 24633876 DOI: 10.1128/jb.01483-14] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Escherichia coli, the small multidrug resistance (SMR) transporter protein EmrE confers host resistance to a broad range of toxic quaternary cation compounds (QCC) via proton motive force in the plasma membrane. Biologically produced QCC also act as EmrE osmoprotectant substrates within the cell and participate in host pH regulation and osmotic tolerance. Although E. coli EmrE is one of the most well-characterized SMR members, it is unclear how the substrates it transports into the periplasm escape across the outer membrane (OM) in Gram-negative bacteria. We tested the hypothesis that E. coli EmrE relies on an unidentified OM protein (OMP) to complete the extracellular release of its QCC. Eleven OMP candidates were screened using an alkaline phenotypic growth assay to identify OMP involvement in EmrE-mediated QCC efflux. E. coli single-gene deletion strains were transformed with plasmid-carried copies of emrE to detect reduced-growth and rescued-growth phenotypes under alkaline conditions. Among the 11 candidates, only the ΔompW strain showed rescued alkaline growth tolerance when transformed with pEmrE, supporting the corresponding protein's involvement in EmrE osmoprotectant efflux. Coexpression of plasmids carrying the ompW and emrE genes transformed into the E. coli ΔompW and ΔemrE strains demonstrated a functional complementation restoring the original alkaline loss-of-growth phenotype. Methyl viologen drug resistance assays of pEmrE and pOmpW plasmid-complemented E. coli ΔompW and wild-type strains found higher host drug resistance than with other plasmid combinations. This study confirms our hypothesis that the porin OmpW participates in the efflux of EmrE-specific substrates across the OM.
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24
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Yamasaki S, Nagasawa S, Fukushima A, Hayashi-Nishino M, Nishino K. Cooperation of the multidrug efflux pump and lipopolysaccharides in the intrinsic antibiotic resistance of Salmonella enterica serovar Typhimurium. J Antimicrob Chemother 2013; 68:1066-70. [PMID: 23378414 PMCID: PMC3625434 DOI: 10.1093/jac/dks528] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES In Gram-negative bacteria, drug susceptibility is associated with multidrug efflux systems and an outer membrane (OM) barrier. Previous studies revealed that Salmonella enterica serovar Typhimurium has 10 functional drug efflux pumps. Among them, AcrB is a major factor to maintain the intrinsic drug resistance in this organism. The lipopolysaccharide (LPS) content of OM is also important for resistance to lipophilic drugs; however, the interplay between the multidrug efflux pump and LPS in the intrinsic antibiotic resistance of Salmonella remains to be studied in detail. The aim of this study was to investigate the relationship between AcrB and LPS in the intrinsic drug resistance of this organism. METHODS The genes encoding LPS core biosynthetic proteins and AcrB were disrupted from the wild-type S. enterica strain ATCC 14028s. The plasmid carrying acrB was transformed into these mutants and then the drug susceptibilities of the mutants and transformants were determined. RESULTS Our results showed that the levels of Salmonella intrinsic antibiotic resistance were decreased when the length and branches of core oligosaccharide were lost. Furthermore, the deletion of acrB reduced multidrug resistance of all LPS mutants and AcrB production from the plasmid complemented this phenotype. However, AcrB production could not completely compensate for LPS function in intrinsic resistance. CONCLUSIONS Both pump inactivation and shortened LPS enhanced drug susceptibility, although the maximum susceptibility was achieved when the two were combined. Hence, these results indicated that the multidrug efflux system and OM barrier are both essential for maintaining intrinsic antibiotic resistance in Salmonella.
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Affiliation(s)
- Seiji Yamasaki
- Laboratory of Microbiology and Infectious Diseases, Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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Hayashi-Nishino M, Fukushima A, Nishino K. Impact of hfq on the intrinsic drug resistance of salmonella enterica serovar typhimurium. Front Microbiol 2012; 3:205. [PMID: 22675323 PMCID: PMC3366549 DOI: 10.3389/fmicb.2012.00205] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 05/18/2012] [Indexed: 01/22/2023] Open
Abstract
Salmonella enterica is an important enteric pathogen, and its various serovars cause both systemic and intestinal diseases in humans and domestic animals. The emergence of multidrug-resistant strains of Salmonella, leading to increased morbidity and mortality, has further complicated its management. Hfq is an RNA chaperon that mediates the binding of small RNAs to mRNA and assists in post-transcriptional gene regulation in bacteria. Although Hfq is related to important phenotypes including virulence in Salmonella, its role in the drug resistance of this organism is unknown. The aim of this study was to investigate the role of Hfq in intrinsic drug resistance of S. enterica serovar Typhimurium. hfq Mutant was susceptible to acriflavine. Although there is a relationship between the production of the AcrB multidrug efflux pump and Hfq in Escherichia coli, the deletion of the drug efflux acrB did not impair the effect of hfq deletion on Salmonella susceptibility. In contrast, the deletion of another drug efflux gene, smvA, impaired the effect of hfq deletion on acriflavine susceptibility. These results indicate that Hfq regulates the intrinsic drug resistance, and it may influence drug susceptibility by regulating SmvA in Salmonella.
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Affiliation(s)
- Mitsuko Hayashi-Nishino
- Laboratory of Microbiology and Infectious Diseases, Institute of Scientific and Industrial Research, Osaka University Ibaraki, Osaka, Japan
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Villagra NA, Fuentes JA, Jofré MR, Hidalgo AA, García P, Mora GC. The carbon source influences the efflux pump-mediated antimicrobial resistance in clinically important Gram-negative bacteria. J Antimicrob Chemother 2012; 67:921-7. [PMID: 22258924 DOI: 10.1093/jac/dkr573] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES Multidrug efflux pumps are proteins known to play an important role in resistance in bacteria. These proteins are located in the inner membrane (IM), together with many other proteins, including inducible permeases that participate in the uptake of non-phosphotransferase system (PTS) carbohydrates (i.e. carbohydrates uptaken by mechanisms other than the PTS). However, lipid bilayer space in the IM is limited. Therefore, we examined whether the overexpression of unrelated IM proteins is able to interfere with the efflux-mediated resistance mechanism, consequently increasing the susceptibility towards different antimicrobial compounds. METHODS We cultured bacteria under different conditions that increase the synthesis of unrelated IM proteins, either by using a non-PTS carbohydrate as the sole carbon source or by artificially overexpressing IM proteins, prior to determining the resistance to different antimicrobial compounds by disc diffusion assays. RESULTS We observed that efflux-pump-mediated resistance is affected by the carbon source in all the strains tested, exhibiting increased susceptibility when a non-PTS carbohydrate was used as the sole carbon source. Moreover, when we artificially overexpressed an unrelated IM protein, we also observed decreased efflux-mediated resistance. CONCLUSIONS These results strongly suggest that overexpression of IM proteins, by using a non-PTS carbohydrate as the sole carbon source, or by artificially introducing a high number of copies of an unrelated IM protein, competes with the antibiotic efflux systems, thereby decreasing the efflux-mediated resistance to different antimicrobial compounds. This sort of competition arises because of the limited available space in the bacterial IM, or by an unknown mechanism.
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Affiliation(s)
- Nicolás A Villagra
- Laboratorio de Microbiología, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile
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Bridier A, Briandet R, Thomas V, Dubois-Brissonnet F. Resistance of bacterial biofilms to disinfectants: a review. BIOFOULING 2011; 27:1017-32. [PMID: 22011093 DOI: 10.1080/08927014.2011.626899] [Citation(s) in RCA: 519] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A biofilm can be defined as a community of microorganisms adhering to a surface and surrounded by a complex matrix of extrapolymeric substances. It is now generally accepted that the biofilm growth mode induces microbial resistance to disinfection that can lead to substantial economic and health concerns. Although the precise origin of such resistance remains unclear, different studies have shown that it is a multifactorial process involving the spatial organization of the biofilm. This review will discuss the mechanisms identified as playing a role in biofilm resistance to disinfectants, as well as novel anti-biofilm strategies that have recently been explored.
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Affiliation(s)
- A Bridier
- AgroParisTech, UMR MICALIS, F-91300 Massy, France
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