1
|
Cao W, Du W, Fang S, Wu Q, Wei Z, Xie Z, Su Y, Wu Y, Luo J. Parachlorometaxylenol stress caused multidrug-type antibiotic resistance genes proliferation via simultaneously reshaping microbial community and interfering metabolic traits during wastewater treatment process. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 357:124454. [PMID: 38936035 DOI: 10.1016/j.envpol.2024.124454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 05/05/2024] [Accepted: 06/25/2024] [Indexed: 06/29/2024]
Abstract
Despite biological wastewater treatment processes (e.g., sequencing batch reactors (SBR)) being able to reduce the dissemination of antibiotic resistance genes (ARGs), the variation of ARGs under exogenous pollutant stress is an open question. This work investigated the impacts of para-chloro-meta-xylenol (PCMX, typical antibacterial contaminants) on ARGs spread in long-term SBR operation. Although the SBR process inherently decreased ARGs abundance, the presence of PCMX substantially amplified both the prevalence (mainly multidrug) and abundance of total ARGs (1.17-fold of the control). Further analysis demonstrated that PCMX disintegrated sludge structures as well as increased membrane permeability, facilitating the release of mobile genetic elements and subsequent horizontal transfer of ARGs. In addition, PCMX selectively enriched potential ARG hosts, notably Nitrospira and Candidatus Accumulibacter, which predominantly served as multidrug ARG hosts. Concurrently, the self-adaptive functions of ARGs hosts in the PCMX-exposed SBR system were activated via quorum sensing, two-component regulatory system, ATP-binding cassette transporters, and bacterial secretion system. The upregulation of these metabolic pathways also contributed to the dissemination of ARGs.
Collapse
Affiliation(s)
- Wangbei Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, China
| | - Wei Du
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, China
| | - Shiyu Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, China
| | - Qian Wu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, China
| | - Zihao Wei
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, China
| | - Zhihuai Xie
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, China
| | - Yinglong Su
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Yang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China.
| |
Collapse
|
2
|
Zhang J, Xu Z, Chu W, Ju F, Jin W, Li P, Xiao R. Residual chlorine persistently changes antibiotic resistance gene composition and increases the risk of antibiotic resistance in sewer systems. WATER RESEARCH 2023; 245:120635. [PMID: 37738943 DOI: 10.1016/j.watres.2023.120635] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 09/24/2023]
Abstract
During the COVID-19 pandemic, excessive amounts of disinfectants and their transformation products entered sewer systems worldwide, which was an extremely rare occurrence before. The stress of residual chlorine and disinfection by-products is not only likely to promote the spread of antibiotic resistance genes (ARGs), but also leads to the enrichment of chlorine-resistant bacteria that may also be resistant to antibiotics. Therefore, the potential impact of such discharge on ARG composition should be studied and the health risks should be assessed. Thus, this study combined high-throughput 16S rRNA gene amplicon sequencing and metagenomic analysis with long-term batch tests that involved two stages of stress and recovery to comprehensively evaluate the impact of residual chlorine on the microbial community and ARG compositions in sewer systems. The tests demonstrated that the disturbance of the microbial community structure by residual chlorine was reversible, but the change in ARG composition was persistent. This study found that vertical propagation and horizontal gene transfer jointly drove ARG composition succession in the biofilm, while the driving force was mainly horizontal gene transfer in the sediment. In this process, the biocide resistance gene (BRG) subtype chtR played an important role in promoting co-selection with ARGs through plasmids and integrative and conjugative elements. Moreover, it was further shown that the addition of sodium hypochlorite increased the risk of ARGs to human health, even after discontinuation of dosing, signifying that the impact was persistent. In general, this study strengthens the co-selection theory of ARGs and BRGs, and calls for improved disinfection strategies and more environmentally friendly disinfectants.
Collapse
Affiliation(s)
- Jingyi Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Zuxin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Feng Ju
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China
| | - Wei Jin
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Peng Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; College of Resources and Environmental Engineering, Shandong Agriculture and Engineering University, Jinan, Shandong 250100, China
| | - Rong Xiao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| |
Collapse
|
3
|
De Gaetano GV, Lentini G, Famà A, Coppolino F, Beninati C. Antimicrobial Resistance: Two-Component Regulatory Systems and Multidrug Efflux Pumps. Antibiotics (Basel) 2023; 12:965. [PMID: 37370284 DOI: 10.3390/antibiotics12060965] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
The number of multidrug-resistant bacteria is rapidly spreading worldwide. Among the various mechanisms determining resistance to antimicrobial agents, multidrug efflux pumps play a noteworthy role because they export extraneous and noxious substrates from the inside to the outside environment of the bacterial cell contributing to multidrug resistance (MDR) and, consequently, to the failure of anti-infective therapies. The expression of multidrug efflux pumps can be under the control of transcriptional regulators and two-component systems (TCS). TCS are a major mechanism by which microorganisms sense and reply to external and/or intramembrane stimuli by coordinating the expression of genes involved not only in pathogenic pathways but also in antibiotic resistance. In this review, we describe the influence of TCS on multidrug efflux pump expression and activity in some Gram-negative and Gram-positive bacteria. Taking into account the strict correlation between TCS and multidrug efflux pumps, the development of drugs targeting TCS, alone or together with already discovered efflux pump inhibitors, may represent a beneficial strategy to contribute to the fight against growing antibiotic resistance.
Collapse
Affiliation(s)
| | - Germana Lentini
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
| | - Agata Famà
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
| | - Francesco Coppolino
- Department of Biomedical, Dental and Imaging Sciences, University of Messina, 98124 Messina, Italy
| | - Concetta Beninati
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
- Scylla Biotech Srl, 98124 Messina, Italy
| |
Collapse
|
4
|
Schwarz J, Schumacher K, Brameyer S, Jung K. Bacterial battle against acidity. FEMS Microbiol Rev 2022; 46:6652135. [PMID: 35906711 DOI: 10.1093/femsre/fuac037] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 07/11/2022] [Accepted: 07/27/2022] [Indexed: 01/09/2023] Open
Abstract
The Earth is home to environments characterized by low pH, including the gastrointestinal tract of vertebrates and large areas of acidic soil. Most bacteria are neutralophiles, but can survive fluctuations in pH. Herein, we review how Escherichia, Salmonella, Helicobacter, Brucella, and other acid-resistant Gram-negative bacteria adapt to acidic environments. We discuss the constitutive and inducible defense mechanisms that promote survival, including proton-consuming or ammonia-producing processes, cellular remodeling affecting membranes and chaperones, and chemotaxis. We provide insights into how Gram-negative bacteria sense environmental acidity using membrane-integrated and cytosolic pH sensors. Finally, we address in more detail the powerful proton-consuming decarboxylase systems by examining the phylogeny of their regulatory components and their collective functionality in a population.
Collapse
Affiliation(s)
- Julia Schwarz
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Kilian Schumacher
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Sophie Brameyer
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Kirsten Jung
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| |
Collapse
|
5
|
Dale AG, Porcu A, Mann J, Neidle S. The mechanism of resistance in Escherichia coli to ridinilazole and other antibacterial head-to-head bis-benzimidazole compounds. Med Chem Res 2022. [DOI: 10.1007/s00044-022-02918-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AbstractThe appY gene has been characterised as conferring resistance to a novel series of antimicrobial benzimidazole derivatives in E. coli MC1061 cells when expressed in high copy-number. A microarray approach was used to identify genes involved in the mechanism of appY-mediated antibacterial resistance, that were up- or down-regulated following induction of the gene in the appY knockout strain JW0553. In total, expression of 90 genes was induced and 48 repressed greater than 2.5-fold (P < 0.05), 45 min after appY induction. Over half the genes up-regulated following appY expression had confirmed or putative roles in acid resistance (AR) and response to oxidative and antibiotic stresses. These included the genes for MdtE and MdtF, which form a multi-drug transporter with TolC and have been implicated in resistance to several antibiotics including erythromycin. Amongst the acid resistance genes were gadAB and adiAC encoding the glutamate-dependant (AR2) and arginine-dependant (AR3) acid resistance systems respectively, in addition to the transcriptional activators of these systems gadE and gadX. In agreement with earlier studies, appA, appCB and hyaA-F were also up-regulated following induction of appY. This study has also confirmed that over-expression of mdtEF confers resistance to these antibacterial benzimidazoles, indicating that the observation of appY conferring resistance to these compounds, proceeds through an appY-mediated up-regulation of this efflux transporter. To assess the importance of the AppY enzyme to acid stress responses, the percentage survival of bacteria in acidified media (pH ≤ 2) was measured. From an initial input of 1 × 106 CFU/ml, the wild-type strain MG1655 showed 7.29% and 0.46% survival after 2 and 4 h, respectively. In contrast, strain JW0553 in which appY is deleted was completely killed by the treatment. Transformation of JW0553 with a plasmid carrying appY returned survival to wild-type levels (7.85% and 1.03% survival at 2 and 4 h). Further dissection of the response by prior induction of each of the three AR systems has revealed that AR1 and AR3 were most affected by the absence of appY. This work highlights an important and previously unidentified role for the AppY enzyme in mediating the responses to several stress conditions. It is likely that the appY gene fits into a complex transcriptional regulatory network involving σS and gadE and gadX. Further work to pinpoint its position in such a hierarchy and to assess the contribution of appY to oxidative stress responses should help determine its full significance. This work is also consistent with recent studies in C. difficile showing that the mechanism of action of ridinilazole involves AT-rich DNA minor groove binding.
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: 43] [Impact Index Per Article: 21.5] [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
|
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: 53] [Impact Index Per Article: 17.7] [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.
Collapse
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
| |
Collapse
|
8
|
The Two-Component System RstA/RstB Regulates Expression of Multiple Efflux Pumps and Influences Anaerobic Nitrate Respiration in Pseudomonas fluorescens. mSystems 2021; 6:e0091121. [PMID: 34726491 PMCID: PMC8562477 DOI: 10.1128/msystems.00911-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Multidrug resistance (MDR) efflux pumps are involved in bacterial intrinsic resistance to multiple antimicrobials. Expression of MDR efflux pumps can be either constitutive or transiently induced by various environmental signals, which are typically perceived by bacterial two-component systems (TCSs) and relayed to the bacterial nucleoid, where gene expression is modulated for niche adaptation. Here, we demonstrate that RstA/RstB, a TCS previously shown to control acid-induced and biofilm-related genes in Escherichiacoli, confers resistance to multiple antibiotics in Pseudomonas fluorescens by directly regulating the MDR efflux pumps EmhABC and MexCD-OprJ. Moreover, we show that phosphorylation of the conserved Asp52 residue in RstA greatly enhances RstA-DNA interaction, and regulation of the multidrug resistance by RstA/RstB is dependent on the phosphorylation of the RstA Asp52 residue by RstB. Proteome analysis reveals RstA/RstB also positively regulates the efflux pump MexEF-OprN and enzymes involved in anaerobic nitrate respiration and pyoverdine biosynthesis. Our results suggest that, by coupling the expression of multiple efflux pumps and anaerobic nitrate respiration, RstA/RstB could play a role in defense against nitrosative stress caused by anaerobic nitrate respiration. IMPORTANCE Microenvironmental hypoxia typically increases bacterial multidrug resistance by elevating expression of multidrug efflux pumps, but the precise mechanism is currently not well understood. Here, we showed that the two-component system RstA/RstB not only positively regulated expression of several efflux pumps involved in multidrug resistance, but also promoted expression of enzymes involved in anaerobic nitrate respiration and pyoverdine biosynthesis. These results suggested that, by upregulating expression of efflux pumps and pyoverdine biosynthesis-related enzymes, RstA/RstB could play a role in promoting bacterial tolerance to hypoxia by providing protection against nitrosative stress.
Collapse
|
9
|
Gulyuk AV, LaJeunesse DR, Collazo R, Ivanisevic A. Tuning Microbial Activity via Programmatic Alteration of Cell/Substrate Interfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2004655. [PMID: 34028885 PMCID: PMC10167751 DOI: 10.1002/adma.202004655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 11/11/2020] [Indexed: 05/11/2023]
Abstract
A wide portfolio of advanced programmable materials and structures has been developed for biological applications in the last two decades. Particularly, due to their unique properties, semiconducting materials have been utilized in areas of biocomputing, implantable electronics, and healthcare. As a new concept of such programmable material design, biointerfaces based on inorganic semiconducting materials as substrates introduce unconventional paths for bioinformatics and biosensing. In particular, understanding how the properties of a substrate can alter microbial biofilm behavior enables researchers to better characterize and thus create programmable biointerfaces with necessary characteristics on demand. Herein, the current status of advanced microorganism-inorganic biointerfaces is summarized along with types of responses that can be observed in such hybrid systems. This work identifies promising inorganic material types along with target microorganisms that will be critical for future research on programmable biointerfacial structures.
Collapse
Affiliation(s)
- Alexey V Gulyuk
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Dennis R LaJeunesse
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina-Greensboro, Greensboro, NC, 27401, USA
| | - Ramon Collazo
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Albena Ivanisevic
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| |
Collapse
|
10
|
Inada S, Okajima T, Utsumi R, Eguchi Y. Acid-Sensing Histidine Kinase With a Redox Switch. Front Microbiol 2021; 12:652546. [PMID: 34093469 PMCID: PMC8174306 DOI: 10.3389/fmicb.2021.652546] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/19/2021] [Indexed: 12/22/2022] Open
Abstract
The EvgS/EvgA two-component signal transduction system in Escherichia coli is activated under mildly acidic pH conditions. Upon activation, this system induces the expression of a number of genes that confer acid resistance. The EvgS histidine kinase sensor has a large periplasmic domain that is required for perceiving acidic signals. In addition, we have previously proposed that the cytoplasmic linker region of EvgS is also involved in the activation of this sensor. The cytoplasmic linker region resembles a Per-ARNT-Sim (PAS) domain, which is known to act as a molecular sensor that is responsive to chemical and physical stimuli and regulates the activity of diverse effector domains. Our EvgS/EvgA reporter assays revealed that under EvgS-activating mildly acidic pH conditions, EvgS was activated only during aerobic growth conditions, and not during anaerobic growth. Studies using EvgS mutants revealed that C671A and C683A mutations in the cytoplasmic PAS domain activated EvgS even under anaerobic conditions. Furthermore, among the electron carriers of the electron transport chain, ubiquinone was required for EvgS activation. The present study proposes a model of EvgS activation by oxidation and suggests that the cytoplasmic PAS domain serves as an intermediate redox switch for this sensor.
Collapse
Affiliation(s)
- Shinya Inada
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Japan
| | - Toshihide Okajima
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Japan
| | - Ryutaro Utsumi
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Japan
| | - Yoko Eguchi
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Japan
| |
Collapse
|
11
|
Zhu T, Wang Z, McMullen LM, Raivio T, Simpson DJ, Gänzle MG. Contribution of the Locus of Heat Resistance to Growth and Survival of Escherichia coli at Alkaline pH and at Alkaline pH in the Presence of Chlorine. Microorganisms 2021; 9:701. [PMID: 33800639 PMCID: PMC8067161 DOI: 10.3390/microorganisms9040701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 12/15/2022] Open
Abstract
The locus of heat resistance (LHR) confers resistance to extreme heat, chlorine and oxidative stress in Escherichia coli. This study aimed to determine the function of the LHR in maintaining bacterial cell envelope homeostasis, the regulation of the genes comprising the LHR and the contribution of the LHR to alkaline pH response. The presence of the LHR did not affect the activity of the Cpx two-component regulatory system in E. coli, which was measured to quantify cell envelope stress. The LHR did not alter E. coli MG1655 growth rate in the range of pH 6.9 to 9.2. However, RT-qPCR results indicated that the expression of the LHR was elevated at pH 8.0 when CpxR was absent. The LHR did not improve survival of E. coli MG1655 at extreme alkaline pH (pH = 11.0 to 11.2) but improved survival at pH 11.0 in the presence of chlorine. Therefore, we conclude that the LHR confers resistance to extreme alkaline pH in the presence of oxidizing agents. Resistance to alkaline pH is regulated by an endogenous mechanism, including the Cpx envelope stress response, whereas the LHR confers resistance to extreme alkaline pH only in the presence of additional stress such as chlorine.
Collapse
Affiliation(s)
- Tongbo Zhu
- Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada; (T.Z.); (Z.W.); (L.M.M.); (D.J.S.)
| | - Zhiying Wang
- Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada; (T.Z.); (Z.W.); (L.M.M.); (D.J.S.)
| | - Lynn M. McMullen
- Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada; (T.Z.); (Z.W.); (L.M.M.); (D.J.S.)
| | - Tracy Raivio
- Department of Biological Science, University of Alberta, Edmonton, AB T6G 2E9, Canada;
| | - David J. Simpson
- Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada; (T.Z.); (Z.W.); (L.M.M.); (D.J.S.)
| | - Michael G. Gänzle
- Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada; (T.Z.); (Z.W.); (L.M.M.); (D.J.S.)
| |
Collapse
|
12
|
|
13
|
Yu L, Li W, Xue M, Li J, Chen X, Ni J, Shang F, Xue T. Regulatory Role of the Two-Component System BasSR in the Expression of the EmrD Multidrug Efflux in Escherichia coli. Microb Drug Resist 2020; 26:1163-1173. [PMID: 32379525 DOI: 10.1089/mdr.2019.0412] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Due to excessive use of antimicrobial agents in the treatment of infectious diseases, bacteria have developed resistance to antibacterial drugs and toxic compounds. The development of multidrug efflux pumps is one of the important mechanisms of bacterial drug resistance. A multidrug efflux pump, EmrD, belonging to the major facilitator superfamily of transporters, confers resistance to many antimicrobial agents. BasSR, a typical two-component signal transduction system (TCS), regulates susceptibility to the cationic antimicrobial peptide, polymyxin B, and the anionic bile detergent, deoxycholic acid, in Escherichia coli. However, whether or not the BasSR TCS affects susceptibility or resistance to other antimicrobial agents and transcription of emrD has not been reported in E. coli. In the present study, we constructed the basSR mutants of wild-type MG1655 and clinical strain APECX40 and performed antimicrobial susceptibility testing, antibacterial activity assays, real-time reverse transcription-PCR experiments and electrophoretic mobility shift assays (EMSA) to investigate the molecular mechanism by which BasSR regulates the EmrD multidrug efflux pump. Results showed that the basSR mutation increased cell susceptibility to eight antimicrobial agents, including ciprofloxacin, norfloxacin, doxycycline, tetracycline, clindamycin, lincomycin, erythromycin, and sodium dodecyl sulfate, by downregulating the transcriptional levels of emrD. Furthermore, EMSA indicated that BasR could directly bind to the emrD promoter. Therefore, this study was the first to demonstrate that BasSR activates transcription of emrD by binding directly to its promoter region, and then decreases susceptibility to various antimicrobial agents in E. coli strains, APECX40 and MG1655.
Collapse
Affiliation(s)
- Lumin Yu
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Wenchang Li
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Mei Xue
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Hefei, China
| | - Jing Li
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Xiaolin Chen
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Jingtian Ni
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Fei Shang
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Ting Xue
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| |
Collapse
|
14
|
Dean SN, Milton ME, Cavanagh J, van Hoek ML. Francisella novicida Two-Component System Response Regulator BfpR Modulates iglC Gene Expression, Antimicrobial Peptide Resistance, and Biofilm Production. Front Cell Infect Microbiol 2020; 10:82. [PMID: 32232010 PMCID: PMC7082314 DOI: 10.3389/fcimb.2020.00082] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 02/18/2020] [Indexed: 12/20/2022] Open
Abstract
Response regulators are a critical part of the two-component system of gene expression regulation in bacteria, transferring a signal from a sensor kinase into DNA binding activity resulting in alteration of gene expression. In this study, we investigated a previously uncharacterized response regulator in Francisella novicida, FTN_1452 that we have named BfpR (Biofilm-regulating Francisella protein Regulator, FTN_1452). In contrast to another Francisella response regulator, QseB/PmrA, BfpR appears to be a negative regulator of biofilm production, and also a positive regulator of antimicrobial peptide resistance in this bacterium. The protein was crystallized and X-ray crystallography studies produced a 1.8 Å structure of the BfpR N-terminal receiver domain revealing interesting insight into its potential interaction with the sensor kinase. Structural analysis of BfpR places it in the OmpR/PhoP family of bacterial response regulators along with WalR and ResD. Proteomic and transcriptomic analyses suggest that BfpR overexpression affects expression of the critical Francisella virulence factor iglC, as well as other proteins in the bacterium. We demonstrate that mutation of bfpR is associated with an antimicrobial peptide resistance phenotype, a phenotype also associated with other response regulators, for the human cathelicidin peptide LL-37 and a sheep antimicrobial peptide SMAP-29. F. novicida with mutated bfpR replicated better than WT in intracellular infection assays in human-derived macrophages suggesting that the down-regulation of iglC expression in bfpR mutant may enable this intracellular replication to occur. Response regulators have been shown to play important roles in the regulation of bacterial biofilm production. We demonstrate that F. novicida biofilm formation was highly increased in the bfpR mutant, corresponding to altered glycogen synthesis. Waxworm infection experiments suggest a role of BfpR as a negative modulator of iglC expression with de-repression by Mg2+. In this study, we find that the response regulator BfpR may be a negative regulator of biofilm formation, and a positive regulator of antimicrobial peptide resistance in F. novicida.
Collapse
Affiliation(s)
- Scott N Dean
- National Center for Biodefense and Infectious Diseases, and School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Morgan E Milton
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - John Cavanagh
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - Monique L van Hoek
- National Center for Biodefense and Infectious Diseases, and School of Systems Biology, George Mason University, Manassas, VA, United States
| |
Collapse
|
15
|
Abstract
Infections arising from multidrug-resistant pathogenic bacteria are spreading rapidly throughout the world and threaten to become untreatable. The origins of resistance are numerous and complex, but one underlying factor is the capacity of bacteria to rapidly export drugs through the intrinsic activity of efflux pumps. In this Review, we describe recent advances that have increased our understanding of the structures and molecular mechanisms of multidrug efflux pumps in bacteria. Clinical and laboratory data indicate that efflux pumps function not only in the drug extrusion process but also in virulence and the adaptive responses that contribute to antimicrobial resistance during infection. The emerging picture of the structure, function and regulation of efflux pumps suggests opportunities for countering their activities.
Collapse
|
16
|
YshB Promotes Intracellular Replication and Is Required for Salmonella Virulence. J Bacteriol 2019; 201:JB.00314-19. [PMID: 31182500 DOI: 10.1128/jb.00314-19] [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: 05/01/2019] [Accepted: 06/07/2019] [Indexed: 11/20/2022] Open
Abstract
Salmonella virulence requires the initial invasion of host cells, followed by modulation of the intracellular environment for survival and replication. In an effort to characterize the role of small RNAs in Salmonella pathogenesis, we inadvertently identified a 5-kDa protein named YshB that is involved in the intracellular survival of Salmonella We show here that yshB expression is upregulated upon entry into macrophages. When yshB expression is upregulated before bacterial entry, invasion efficiency is inhibited. Lack of YshB resulted in reduced bacterial survival within the macrophages and led to reduced virulence in a mouse model of infection.IMPORTANCE Salmonella gastroenteritis is one of the most common causes of foodborne disease, possibly affecting millions of people globally each year. Here we characterize the role of a novel small protein, YshB, in mediating Salmonella intracellular survival. This elucidation adds to the body of knowledge regarding how this bacterium achieves intracellular survival.
Collapse
|
17
|
Luo Q, Niu T, Wang Y, Yin J, Wan F, Yao M, Lu H, Xiao Y, Li L. In vitro reduction of colistin susceptibility and comparative genomics reveals multiple differences between MCR-positive and MCR-negative colistin-resistant Escherichia coli. Infect Drug Resist 2019; 12:1665-1674. [PMID: 31354315 PMCID: PMC6580138 DOI: 10.2147/idr.s210245] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 05/13/2019] [Indexed: 11/23/2022] Open
Abstract
Objectives: Although resistance to colistin is increasingly reported from clinical settings, the genetic mechanisms that lead to colistin resistance in Escherichia coli have not been fully characterized. Here, we assess the evolution of colistin resistance in clinical isolates of mobilized colistin resistance (MCR)-negative and MCR-positive Escherichia coli. Methods: Spontaneously mutated colistin-resistant progeny were evolved using a step-wise reduction of colistin susceptibility. Resistance phenotypes were confirmed by minimum inhibitory concentration (MIC) determination, and the probable resistance mechanisms were investigated using PCR and reverse transcription-quantitative PCR. Mutated genes of the laboratory-evolved mutants were identified by whole-genome sequencing and comparative genomics. Fitness costs and serum resistance of the mutants were also compared to the corresponding wild types. Results: MCR-negative isolates displayed higher increases in MICs than did MCR-positive isolates following colistin exposure. Upregulation of pmrAB and associated genes was evident among MCR-negative isolates but not MCR-positive isolates. Comparative genomic analysis of mutants and their corresponding wild-types (WTs) revealed numerous mutations in genes encoding membrane transporters and two-component systems. Additionally, MCR-negative mutants exhibited higher fitness costs than MCR-positive mutants compared with their corresponding WTs but displayed similar serum resistance. Conclusion: Our findings reveal multiple differences between MCR-positive and MCR-negative E. coli strains following colistin exposure, which provide reference values for clinical medication.
Collapse
Affiliation(s)
- Qixia Luo
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases , Hangzhou, The First Affiliated Hospital, College of Medicine, Zhejiang University, People's Republic of China
| | - Tianshui Niu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases , Hangzhou, The First Affiliated Hospital, College of Medicine, Zhejiang University, People's Republic of China
| | - Yuan Wang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases , Hangzhou, The First Affiliated Hospital, College of Medicine, Zhejiang University, People's Republic of China
| | - Jianhua Yin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, People's Republic of China
| | - Fen Wan
- College of Laboratory Medicine, Hangzhou Medical College, Hangzhou, People's Republic of China
| | - Mingfei Yao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases , Hangzhou, The First Affiliated Hospital, College of Medicine, Zhejiang University, People's Republic of China
| | - Haifeng Lu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases , Hangzhou, The First Affiliated Hospital, College of Medicine, Zhejiang University, People's Republic of China
| | - Yonghong Xiao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases , Hangzhou, The First Affiliated Hospital, College of Medicine, Zhejiang University, People's Republic of China
| | - Lanjuan Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases , Hangzhou, The First Affiliated Hospital, College of Medicine, Zhejiang University, People's Republic of China
| |
Collapse
|
18
|
Tierney AR, Rather PN. Roles of two-component regulatory systems in antibiotic resistance. Future Microbiol 2019; 14:533-552. [PMID: 31066586 DOI: 10.2217/fmb-2019-0002] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Two-component regulatory systems (TCSs) are a major mechanism by which bacteria sense and respond to changes in their environment. TCSs typically consist of two proteins that bring about major regulation of the cell genome through coordinated action mediated by phosphorylation. Environmental conditions that activate TCSs are numerous and diverse and include exposure to antibiotics as well as conditions inside a host. The resulting regulatory action often involves activation of antibiotic defenses and changes to cell physiology that increase antibiotic resistance. Examples of resistance mechanisms enacted by TCSs contained in this review span those found in both Gram-negative and Gram-positive species and include cell surface modifications, changes in cell permeability, increased biofilm formation, and upregulation of antibiotic-degrading enzymes.
Collapse
Affiliation(s)
- Aimee Rp Tierney
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA, 30322 USA
| | - Philip N Rather
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA, 30322 USA.,Research Service, Department of Veterans' Affairs, Atlanta VA Health Care System, Decatur, GA, 30033 USA
| |
Collapse
|
19
|
Comprehensive analysis of resistance-nodulation-cell division superfamily (RND) efflux pumps from Serratia marcescens, Db10. Sci Rep 2019; 9:4854. [PMID: 30890721 PMCID: PMC6425002 DOI: 10.1038/s41598-019-41237-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/05/2019] [Indexed: 12/29/2022] Open
Abstract
We investigated the role of the resistance-nodulation-cell division superfamily (RND) efflux system on intrinsic multidrug resistance in Serratia marcescens. We identified eight putative RND efflux system genes in the S. marcescens Db10 genome that included the previously characterized systems, sdeXY, sdeAB, and sdeCDE. Six out of the eight genes conferred multidrug resistance on KAM32, a drug hypersensitive strain of Escherichia coli. Five out of the eight genes conferred resistance to benzalkonium, suggesting the importance of RND efflux systems in biocide resistance in S. marcescens. The energy-dependent efflux activities of five of the pumps were examined using a rhodamine 6 G efflux assay. When expressed in the tolC-deficient strain of E. coli, KAM43, none of the genes conferred resistance on E. coli. When hasF, encoding the S. marcescens TolC ortholog, was expressed in KAM43, all of the genes conferred resistance on E. coli, suggesting that HasF is a major outer membrane protein that is used by all RND efflux systems in this organism. We constructed a sdeXY deletion mutant from a derivative strain of the clinically isolated multidrug-resistant S. marcescens strain and found that the sdeXY deletion mutant was sensitive to a broad spectrum of antimicrobial agents.
Collapse
|
20
|
Liu CJ, Lin CT, Chiang JD, Lin CY, Tay YX, Fan LC, Peng KN, Lin CH, Peng HL. RcsB regulation of the YfdX-mediated acid stress response in Klebsiella pneumoniae CG43S3. PLoS One 2019; 14:e0212909. [PMID: 30818355 PMCID: PMC6394985 DOI: 10.1371/journal.pone.0212909] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 02/12/2019] [Indexed: 12/31/2022] Open
Abstract
In Klebsiella pneumoniae CG43S3, deletion of the response regulator gene rcsB reduced the capsular polysaccharide amount and survival on exposure to acid stress. A comparison of the pH 4.4-induced proteomes between CG43S3 and CG43S3ΔrcsB revealed numerous differentially expressed proteins and one of them, YfdX, which has recently been reported as a periplasmic protein, was absent in CG43S3ΔrcsB. Acid survival analysis was then conducted to determine its role in the acid stress response. Deletion of yfdX increased the sensitivity of K. pneumoniae CG43S3 to a pH of 2.5, and transforming the mutant with a plasmid carrying yfdX restored the acid resistance (AR) levels. In addition, the effect of yfdX deletion was cross-complemented by the expression of the periplasmic chaperone HdeA. Furthermore, the purified recombinant protein YfdX reduced the acid-induced protein aggregation, suggesting that YfdX as well as HdeA functions as a chaperone. The following promoter activity measurement revealed that rcsB deletion reduced the expression of yfdX after the bacteria were subjected to pH 4.4 adaptation. Western blot analysis also revealed that YfdX production was inhibited by rcsB deletion and only the plasmid expressing RcsB or the nonphosphorylated form of RcsB, RcsBD56A, could restore the YfdX production, and the RcsB-mediated complementation was no longer observed when the sensor kinase RcsD gene was deleted. In conclusion, this is the first study demonstrating that YfdX may be involved in the acid stress response as a periplasmic chaperone and that RcsB positively regulates the acid stress response partly through activation of yfdX expression. Moreover, the phosphorylation status of RcsB may affect the YfdX expression under acidic conditions.
Collapse
Affiliation(s)
- Chia-Jui Liu
- Department of Biological Science and Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Ching-Ting Lin
- School of Chinese Medicine, China Medical University, Taichung, Taiwan, Republic of China
| | - Jo-Di Chiang
- Department of Biological Science and Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Chen-Yi Lin
- Department of Biological Science and Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Yen-Xi Tay
- Institute of Molecular Medicine and Biological Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Li-Cheng Fan
- Department of Biological Science and Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Kuan-Nan Peng
- Department of Biological Science and Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Chih-Huan Lin
- Institute of Molecular Medicine and Biological Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Hwei-Ling Peng
- Department of Biological Science and Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
- Institute of Molecular Medicine and Biological Technology, School of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
- * E-mail:
| |
Collapse
|
21
|
Lee HS, Lee S, Kim JS, Lee HR, Shin HC, Lee MS, Jin KS, Kim CH, Ku B, Ryu CM, Kim SJ. Structural and Physiological Exploration of Salmonella Typhi YfdX Uncovers Its Dual Function in Bacterial Antibiotic Stress and Virulence. Front Microbiol 2019; 9:3329. [PMID: 30692978 PMCID: PMC6339873 DOI: 10.3389/fmicb.2018.03329] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 12/21/2018] [Indexed: 12/31/2022] Open
Abstract
YfdX is a prokaryotic protein encoded by several pathogenic bacteria including Salmonella enterica serovar Typhi, which causes one of the most fatal infectious diseases, typhoid fever. YfdX is a product of the yfdXWUVE operon and is known to be under the control of EvgA, a regulator protein controlling the expression of several proteins involved in response to environmental stress, in Escherichia coli. Nevertheless, unlike other proteins encoded by the same operon, the structural and physiological aspects of YfdX have been poorly characterized. Here, we identified a previously unknown pH-dependent stoichiometric conversion of S. Typhi YfdX between dimeric and tetrameric states; this conversion was further analyzed via determining its structure by X-ray crystallography at high resolution and by small-angle X-ray scattering in a solution state and via structure-based mutant studies. Biologically, YfdX was proven to be critically involved in Salmonella susceptibility to two β-lactam antibiotics, penicillin G and carbenicillin, as bacterial growth significantly impaired by its deficiency upon treatment with each of the two antibiotics was recovered by chromosomal complementation. Furthermore, by using Galleria mellonella larvae as an in vivo model of Salmonella infection, we demonstrated that Salmonella virulence was remarkably enhanced by YfdX deficiency, which was complemented by a transient expression of the wild-type or dimeric mutant but not by that of the monomeric mutant. The present study work provides direct evidence regarding the participation of YfdX in Salmonella antibiotic susceptibility and in the modulation of bacterial virulence, providing a new insight into this pathogen's strategies for survival and growth.
Collapse
Affiliation(s)
- Hye Seon Lee
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Biology, Chungnam National University, Daejeon, South Korea
| | - Soohyun Lee
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Jun-Seob Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Hae-Ran Lee
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Ho-Chul Shin
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Moo-Seung Lee
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Kyeong Sik Jin
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, South Korea
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, South Korea
| | - Bonsu Ku
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Choong-Min Ryu
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Biotechnology, University of Science and Technology KRIBB School, Daejeon, South Korea
| | - Seung Jun Kim
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Bioscience, University of Science and Technology KRIBB School, Daejeon, South Korea
| |
Collapse
|
22
|
Comparative study of Salmonella enterica serovar Enteritidis genes expressed within avian and murine macrophages via selective capture of transcribed sequences (SCOTS). Appl Microbiol Biotechnol 2018; 102:6567-6579. [PMID: 29799087 DOI: 10.1007/s00253-018-9067-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 04/26/2018] [Accepted: 05/01/2018] [Indexed: 10/16/2022]
Abstract
Salmonella enterica serovar Enteritidis (SE) is a communicable zoonotic bacterium. Macrophages are essential for Salmonella survival, transmission, and infection. In this study, selective capture of transcribed sequences (SCOTS) was used to screen genes preferentially expressed by SE during contact with macrophages from different hosts. We found 57 predicted genes and 52 genes expressed by SE during interaction with avian HD-11 and murine RAW264.7 cells, respectively. These expressed genes were involved in virulence, metabolism, stress response, transport, regulation, and other functions. Although genes related to survival or metabolic pathways were needed during SE infection, different gene expression profiles of SE occurred in the two macrophage cell lines. qRT-PCR results confirmed that most screened genes were upregulated during infection in contrast to the observation during in vitro cultivation, with different expression levels in infected avian macrophages at 2-h and 7-h post-infection. In addition, in vitro and in vivo competition assays confirmed that SEN3610 (a putative deoR family regulator) and rfaQ (related to LPS synthesis) were closely related to SE virulence in both mice and chickens. Three putative transcriptional regulators, SEN2967, SEN4299, and rtcR, were related to SE colonization in mice, while the ycaM mutation caused decreased infection and survival of SE in HD-11 cells without influencing virulence in mice or chicken. Genes showing differential expression between SE-infected avian and murine macrophages indicate specific pathogen adaptation to enable infection of various hosts.
Collapse
|
23
|
Nishino K. Regulation of the Expression of Bacterial Multidrug Exporters by Two-Component Signal Transduction Systems. Methods Mol Biol 2018; 1700:239-251. [PMID: 29177834 DOI: 10.1007/978-1-4939-7454-2_13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Bacterial multidrug exporters confer resistance to a wide range of antibiotics, dyes, and biocides. Recent studies have shown that there are many multidrug exporters encoded in bacterial genome. For example, it was experimentally identified that E. coli has at least 20 multidrug exporters. Because many of these multidrug exporters have overlapping substrate spectra, it is intriguing that bacteria, with their economically organized genomes, harbor such large sets of multidrug exporter genes. The key to understanding how bacteria utilize these multiple exporters lies in the regulation of exporter expression. Bacteria have developed signaling systems for eliciting a variety of adaptive responses to their environments. These adaptive responses are often mediated by two-component regulatory systems. In this chapter, the method to identify response regulators that affect expression of multidrug exporters is described.
Collapse
Affiliation(s)
- Kunihiko Nishino
- Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan. .,Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
24
|
Roggiani M, Yadavalli SS, Goulian M. Natural variation of a sensor kinase controlling a conserved stress response pathway in Escherichia coli. PLoS Genet 2017; 13:e1007101. [PMID: 29140975 PMCID: PMC5706723 DOI: 10.1371/journal.pgen.1007101] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 11/29/2017] [Accepted: 11/03/2017] [Indexed: 12/02/2022] Open
Abstract
Previous studies have shown that exponentially growing Escherichia coli can detect mild acidity (~pH 5.5) and, in response, synthesize enzymes that protect against severe acid shock. This adaptation is controlled by the EvgS/EvgA phosphorelay, a signal transduction system present in virtually every E. coli isolate whose genome has been sequenced. Here we show that, despite this high level of conservation, the EvgS/EvgA system displays a surprising natural variation in pH-sensing capacity, with some strains entirely non-responsive to low pH stimulus. In most cases that we have tested, however, activation of the EvgA regulon still confers acid resistance. From analyzing selected E. coli isolates, we find that the natural variation results from polymorphisms in the sensor kinase EvgS. We further show that this variation affects the pH response of a second kinase, PhoQ, which senses pH differently from the closely related PhoQ in Salmonella enterica. The within-species diversification described here suggests EvgS likely responds to additional input signals that may be correlated with acid stress. In addition, this work highlights the fact that even for highly conserved sensor kinases, the activities identified from a subset of isolates may not necessarily generalize to other members of the same bacterial species. Bacteria employ a class of proteins, sensor kinases, to sense environmental cues and initiate cellular responses through phosphorylation of partner response regulator proteins. Individual kinases are generally assumed to have the same sensory activity across members of a bacterial species. In this work, we report an unexpected counterexample in which the well-established capacity of the kinase EvgS to sense mild acidity is limited to a subset of Escherichia coli isolates. Despite this natural variation, EvgS activation still confers resistance to acid stress in strains that have lost EvgS pH-sensing activity. Thus, most E. coli share a conserved output of the Evg system but do not require identical sensory functions. This work highlights the potential for significant functional divergence of a sensor kinase within a species and also indicates that there are additional input signals for the highly conserved EvgS protein.
Collapse
Affiliation(s)
- Manuela Roggiani
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Srujana S. Yadavalli
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Mark Goulian
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
- * E-mail:
| |
Collapse
|
25
|
Functional Analysis of Genes Comprising the Locus of Heat Resistance in Escherichia coli. Appl Environ Microbiol 2017; 83:AEM.01400-17. [PMID: 28802266 DOI: 10.1128/aem.01400-17] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/07/2017] [Indexed: 12/21/2022] Open
Abstract
The locus of heat resistance (LHR) is a 15- to 19-kb genomic island conferring exceptional heat resistance to organisms in the family Enterobacteriaceae, including pathogenic strains of Salmonella enterica and Escherichia coli The complement of LHR-comprising genes that is necessary for heat resistance and the stress-induced or growth-phase-induced expression of LHR-comprising genes are unknown. This study determined the contribution of the seven LHR-comprising genes yfdX1GI, yfdX2, hdeDGI, orf11, trxGI, kefB, and psiEGI by comparing the heat resistances of E. coli strains harboring plasmid-encoded derivatives of the different LHRs in these genes. (Genes carry a subscript "GI" [genomic island] if an ortholog of the same gene is present in genomes of E. coli) LHR-encoded heat shock proteins sHSP20, ClpKGI, and sHSPGI are not sufficient for the heat resistance phenotype; YfdX1, YfdX2, and HdeD are necessary to complement the LHR heat shock proteins and to impart a high level of resistance. Deletion of trxGI, kefB, and psiEGI from plasmid-encoded copies of the LHR did not significantly affect heat resistance. The effect of the growth phase and the NaCl concentration on expression from the putative LHR promoter p2 was determined by quantitative reverse transcription-PCR and by a plasmid-encoded p2:GFP promoter fusion. The expression levels of exponential- and stationary-phase E. coli cells were not significantly different, but the addition of 1% NaCl significantly increased LHR expression. Remarkably, LHR expression in E. coli was dependent on a chromosomal copy of evgA In conclusion, this study improved our understanding of the genes required for exceptional heat resistance in E. coli and factors that increase their expression in food.IMPORTANCE The locus of heat resistance (LHR) is a genomic island conferring exceptional heat resistance to several foodborne pathogens. The exceptional level of heat resistance provided by the LHR questions the control of pathogens by current food processing and preparation techniques. The function of LHR-comprising genes and their regulation, however, remain largely unknown. This study defines a core complement of LHR-encoded proteins that are necessary for heat resistance and demonstrates that regulation of the LHR in E. coli requires a chromosomal copy of the gene encoding EvgA. This study provides insight into the function of a transmissible genomic island that allows otherwise heat-sensitive enteric bacteria, including pathogens, to lead a thermoduric lifestyle and thus contributes to the detection and control of heat-resistant enteric bacteria in food.
Collapse
|
26
|
Structural and Functional Analysis of the Escherichia coli Acid-Sensing Histidine Kinase EvgS. J Bacteriol 2017; 199:JB.00310-17. [PMID: 28674068 PMCID: PMC5573083 DOI: 10.1128/jb.00310-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/19/2017] [Indexed: 01/31/2023] Open
Abstract
The EvgS/EvgA two-component system of Escherichia coli is activated in response to low pH and alkali metals and regulates many genes, including those for the glutamate-dependent acid resistance system and a number of efflux pumps. EvgS, the sensor kinase, is one of five unconventional histidine kinases (HKs) in E. coli and has a large periplasmic domain and a cytoplasmic PAS domain in addition to phospho-acceptor, HK and dimerization, internal receiver, and phosphotransfer domains. Mutations that constitutively activate the protein at pH 7 map to the PAS domain. Here, we built a homology model of the periplasmic region of EvgS, based on the structure of the equivalent region of the BvgS homologue, to guide mutagenesis of potential key residues in this region. We show that histidine 226 is required for induction and that it is structurally colocated with a proline residue (P522) at the top of the predicted transmembrane helix that is expected to play a key role in passing information to the cytoplasmic domains. We also show that the constitutive mutations in the PAS domain can be further activated by low external pH. Expression of the cytoplasmic part of the protein alone also gives constitutive activation, which is lost if the constitutive PAS mutations are present. These findings are consistent with a model in which EvgS senses both external and internal pH and is activated by a shift from a tight inactive to a weak active dimer, and we present an analysis of the purified cytoplasmic portion of EvgS that supports this. IMPORTANCE One of the ways bacteria sense their environment is through two-component systems, which have one membrane-bound protein to do the sensing and another inside the cell to turn genes on or off in response to what the membrane-bound protein has detected. The membrane-bound protein must thus be able to detect the stress and signal this detection event to the protein inside the cell. To understand this process, we studied a protein that helps E. coli to survive exposure to low pH, which it must do before taking up residence in the gastrointestinal tract. We describe a predicted structure for the main sensing part of the protein and identify some key residues within it that are involved in the sensing and signaling processes. We propose a mechanism for how the protein may become activated and present some evidence to support our proposal.
Collapse
|
27
|
Wu CJ, Huang YW, Lin YT, Ning HC, Yang TC. Inactivation of SmeSyRy Two-Component Regulatory System Inversely Regulates the Expression of SmeYZ and SmeDEF Efflux Pumps in Stenotrophomonas maltophilia. PLoS One 2016; 11:e0160943. [PMID: 27513575 PMCID: PMC4981351 DOI: 10.1371/journal.pone.0160943] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 07/27/2016] [Indexed: 02/01/2023] Open
Abstract
SmeYZ efflux pump is a critical pump responsible for aminoglycosides resistance, virulence-related characteristics (oxidative stress susceptibility, motility, and secreted protease activity), and virulence in Stenotrophomonas maltophilia. However, the regulatory circuit involved in SmeYZ expression is little known. A two-component regulatory system (TCS), smeRySy, transcribed divergently from the smeYZ operon is the first candidate to be considered. To assess the role of SmeRySy in smeYZ expression, the smeRySy isogenic deletion mutant, KJΔRSy, was constructed by gene replacement strategy. Inactivation of smeSyRy correlated with a higher susceptibility to aminoglycosides concomitant with an increased resistance to chloramphenicol, ciprofloxacin, tetracycline, and macrolides. To elucidate the underlying mechanism responsible for the antimicrobials susceptibility profiles, the SmeRySy regulon was firstly revealed by transcriptome analysis and further confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and promoter transcription fusion constructs assay. The results demonstrate that inactivation of smeRySy decreased the expression of SmeYZ pump and increased the expression of SmeDEF pump, which underlies the ΔsmeSyRy-mediated antimicrobials susceptibility profile. To elucidate the cognate relationship between SmeSy and SmeRy, a single mutant, KJΔRy, was constructed and the complementation assay of KJΔRSy with smeRy were performed. The results support that SmeSy-SmeRy TCS is responsible for the regulation of smeYZ operon; whereas SmeSy may be cognate with another unidentified response regulator for the regulation of smeDEF operon. The impact of inverse expression of SmeYZ and SmeDEF pumps on physiological functions was evaluated by mutants construction, H2O2 susceptibility test, swimming, and secreted protease activity assay. The increased expression of SmeDEF pump in KJΔRSy may compensate, to some extents, the SmeYZ downexpression-mediated compromise with respect to its role in secreted protease activity.
Collapse
Affiliation(s)
- Chao-Jung Wu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, 112, Taiwan
| | - Yi-Wei Huang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, 112, Taiwan
| | - Yi-Tsung Lin
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, 112, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, 112, Taiwan
| | - Hsiao-Chen Ning
- Department of Laboratory Medicine, Chang Gung Memorial Hospital Linkou Branch, Taoyuan, Taiwan
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
| | - Tsuey-Ching Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, 112, Taiwan
- * E-mail:
| |
Collapse
|
28
|
Kilian R, Frasch HJ, Kulik A, Wohlleben W, Stegmann E. The VanRS Homologous Two-Component System VnlRSAb of the Glycopeptide Producer Amycolatopsis balhimycina Activates Transcription of the vanHAXSc Genes in Streptomyces coelicolor, but not in A. balhimycina. Microb Drug Resist 2016; 22:499-509. [PMID: 27420548 PMCID: PMC5036315 DOI: 10.1089/mdr.2016.0128] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In enterococci and in Streptomyces coelicolor, a glycopeptide nonproducer, the glycopeptide resistance genes vanHAX are colocalized with vanRS. The two-component system (TCS) VanRS activates vanHAX transcription upon sensing the presence of glycopeptides. Amycolatopsis balhimycina, the producer of the vancomycin-like glycopeptide balhimycin, also possesses vanHAXAb genes. The genes for the VanRS-like TCS VnlRSAb, together with the carboxypeptidase gene vanYAb, are part of the balhimycin biosynthetic gene cluster, which is located 2 Mb separate from the vanHAXAb. The deletion of vnlRSAb did not affect glycopeptide resistance or balhimycin production. In the A. balhimycina vnlRAb deletion mutant, the vanHAXAb genes were expressed at the same level as in the wild type, and peptidoglycan (PG) analyses proved the synthesis of resistant PG precursors. Whereas vanHAXAb expression in A. balhimycina does not depend on VnlRAb, a VnlRAb-depending regulation of vanYAb was demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR) and RNA-seq analyses. Although VnlRAb does not regulate the vanHAXAb genes in A. balhimycina, its heterologous expression in the glycopeptide-sensitive S. coelicolor ΔvanRSSc deletion mutant restored glycopeptide resistance. VnlRAb activates the vanHAXSc genes even in the absence of VanS. In addition, expression of vnlRAb increases actinorhodin production and influences morphological differentiation in S. coelicolor.
Collapse
Affiliation(s)
- Regina Kilian
- Interfaculty Institute of Microbiology and Infection Medicine Tuebingen, Microbiology/Biotechnology, University of Tuebingen, Tuebingen, Germany
| | - Hans-Joerg Frasch
- Interfaculty Institute of Microbiology and Infection Medicine Tuebingen, Microbiology/Biotechnology, University of Tuebingen, Tuebingen, Germany
| | - Andreas Kulik
- Interfaculty Institute of Microbiology and Infection Medicine Tuebingen, Microbiology/Biotechnology, University of Tuebingen, Tuebingen, Germany
| | - Wolfgang Wohlleben
- Interfaculty Institute of Microbiology and Infection Medicine Tuebingen, Microbiology/Biotechnology, University of Tuebingen, Tuebingen, Germany
- German Centre for Infection Research (DZIF), Partner Site Tuebingen, Tuebingen, Germany
| | - Evi Stegmann
- Interfaculty Institute of Microbiology and Infection Medicine Tuebingen, Microbiology/Biotechnology, University of Tuebingen, Tuebingen, Germany
- German Centre for Infection Research (DZIF), Partner Site Tuebingen, Tuebingen, Germany
| |
Collapse
|
29
|
Reversible thermal unfolding of a yfdX protein with chaperone-like activity. Sci Rep 2016; 6:29541. [PMID: 27404435 PMCID: PMC4941729 DOI: 10.1038/srep29541] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 06/20/2016] [Indexed: 01/16/2023] Open
Abstract
yfdX proteins are ubiquitously present in a large number of virulent bacteria. A member of this family of protein in E. coli is known to be up-regulated by the multidrug response regulator. Their abundance in such bacteria suggests some important yet unidentified functional role of this protein. Here, we study the thermal response and stability of yfdX protein STY3178 from Salmonella Typhi using circular dichroism, steady state fluorescence, dynamic light scattering and nuclear magnetic resonance experiments. We observe the protein to be stable up to a temperature of 45 °C. It folds back to the native conformation from unfolded state at temperature as high as 80 °C. The kinetic measurements of unfolding and refolding show Arrhenius behavior where the refolding involves less activation energy barrier than that of unfolding. We propose a homology model to understand the stability of the protein. Our molecular dynamic simulation studies on this model structure at high temperature show that the structure of this protein is quite stable. Finally, we report a possible functional role of this protein as a chaperone, capable of preventing DTT induced aggregation of insulin. Our studies will have broader implication in understanding the role of yfdX proteins in bacterial function and virulence.
Collapse
|
30
|
Abstract
Bacterial multidrug resistance (MDR) efflux pumps are an important mechanism of antibiotic resistance and are required for many pathogens to cause infection. They are also being harnessed to improve microbial biotechnological processes, including biofuel production. Therefore, scientists of many specialties must be able to accurately measure efflux activity. However, myriad methodologies have been described and the most appropriate method is not always clear. Within the scientific literature, many methods are misused or data arising are misinterpreted. The methods for measuring efflux activity can be split into two groups, (i) those that directly measure efflux and (ii) those that measure the intracellular accumulation of a substrate, which is then used to infer efflux activity. Here, we review the methods for measuring efflux and explore the most recent advances in this field, including single-cell or cell-free technologies and mass spectrometry, that are being used to provide more detailed information about efflux pump activity.
Collapse
|
31
|
Huang H, Sun Y, Yuan L, Pan Y, Gao Y, Ma C, Hu G. Regulation of the Two-Component Regulator CpxR on Aminoglycosides and β-lactams Resistance in Salmonella enterica serovar Typhimurium. Front Microbiol 2016; 7:604. [PMID: 27199934 PMCID: PMC4846824 DOI: 10.3389/fmicb.2016.00604] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/11/2016] [Indexed: 11/13/2022] Open
Abstract
The two-component signal transduction system CpxAR is especially widespread in Gram-negative bacteria. It has been reported that CpxAR contributes to the multidrug resistance (MDR) in Escherichia coli. CpxR is a response regulator in the two-component CpxAR system. The aim of this study was to explore the role of cpxR in the MDR of S. enterica serovar Typhimurium. The minimal inhibitory concentrations (MICs) of various antibiotics commonly used in veterinary medicine for strains JS (a multidrug-susceptible standard strain of S. enterica serovar Typhimurium), JSΔcpxR, JSΔcpxR/pcpxR, JSΔcpxR/pcpxR (*), JSΔcpxRΔacrB, JSΔcpxRΔacrB/pcpxR, JSΔcpxRΔacrB/pcpxR (*), 9 S. enterica serovar Typhimurium isolates (SH1-9), and SH1-9ΔcpxR were determined by the 2-fold broth microdilution method. The relative mRNA expression levels of ompF, ompC, ompW, ompD, tolC, acrB, acrD, acrF, mdtA, marA, and soxS in strains JS, JSΔcpxR, and JSΔcpxR/pcpxR were detected by real-time PCR. The results showed 2- to 4-fold decreases in the MICs of amikacin (AMK), gentamycin (GEN), apramycin (APR), neomycin (NEO), ceftriaxone (CRO), ceftiofur (CEF), and cefquinome (CEQ) for strain JSΔcpxR, as compared to those for the parental strain JS. Likewise, SH1-9ΔcpxR were found to have 2- to 8-fold reduction in resistance to the above antibiotics, except for NEO, as compared to their parental strains SH1-9. Furthermore, 2- to 4-fold further decreases in the MICs of AMK, GEN, APR, and CEF for strain JSΔcpxRΔacrB were observed, as compared to those for strain JSΔacrB. In addition, CpxR overproduction in strain JSΔcpxR led to significant decreases in the mRNA expression levels of ompF, ompC, ompW, ompD, tolC, acrB, marA, and soxS, and significant increases in those of stm3031 and stm1530. Notably, after all strains were induced simultaneously by GEN to the 15th passage at subinhibitory concentrations, strain JSΔcpxR/pcpxR showed significant increases in mRNA expression levels of the efflux pump acrD and mdtA genes, as compared to strain JSΔcpxR. Our results indicate that the two-component regulator CpxR contributes to resistance of S. enterica serovar Typhimurium to aminoglycosides and β-lactams by influencing the expression level of the MDR-related genes.
Collapse
Affiliation(s)
- Hui Huang
- College of Veterinary Medicine, Henan Agricultural University Zhengzhou, China
| | - Yawei Sun
- College of Veterinary Medicine, Henan Agricultural UniversityZhengzhou, China; College of Animal Science and Technology, Henan Institute of Science and TechnologyXinxiang, China
| | - Li Yuan
- College of Veterinary Medicine, Henan Agricultural University Zhengzhou, China
| | - Yushan Pan
- College of Veterinary Medicine, Henan Agricultural University Zhengzhou, China
| | - Yanlin Gao
- Animal Husbandry Bureau of Henan Province Zhengzhou, China
| | - Caihui Ma
- College of Veterinary Medicine, Henan Agricultural University Zhengzhou, China
| | - Gongzheng Hu
- College of Veterinary Medicine, Henan Agricultural University Zhengzhou, China
| |
Collapse
|
32
|
Substrate-dependent dynamics of the multidrug efflux transporter AcrB of Escherichia coli. Sci Rep 2016; 6:21909. [PMID: 26916090 PMCID: PMC4768149 DOI: 10.1038/srep21909] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/01/2016] [Indexed: 02/07/2023] Open
Abstract
The resistance-nodulation-cell division (RND)-type xenobiotic efflux system plays a major role in the multidrug resistance of gram-negative bacteria. The only constitutively expressed RND system of Escherichia coli consists of the inner membrane transporter AcrB, the membrane fusion protein AcrA, and the outer membrane channel TolC. The latter two components are shared with another RND-type transporter AcrD, whose expression is induced by environmental stimuli. Here, we demonstrate how RND-type ternary complexes, which span two membranes and the cell wall, form in vivo. Total internal reflection fluorescence (TIRF) microscopy revealed that most fluorescent foci formed by AcrB fused to green fluorescent protein (GFP) were stationary in the presence of TolC but showed lateral displacements when tolC was deleted. The fraction of stationary AcrB-GFP foci decreased with increasing levels of AcrD. We propose that the AcrB-containing complex becomes unstable upon the induction of AcrD, which presumably replaces AcrB, a process we call “transporter exchange.” This instability is suppressed by AcrB-specific substrates, suggesting that the ternary complex is stabilised when it is in action. These results suggest that the assembly of the RND-type efflux system is dynamically regulated in response to external stimuli, shedding new light on the adaptive antibiotic resistance of bacteria.
Collapse
|
33
|
Saha P, Manna C, Das S, Ghosh M. Antibiotic binding of STY3178, a yfdX protein from Salmonella Typhi. Sci Rep 2016; 6:21305. [PMID: 26892637 PMCID: PMC4759549 DOI: 10.1038/srep21305] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 01/19/2016] [Indexed: 01/18/2023] Open
Abstract
The yfdX family proteins are known for long time to occur in various virulent bacteria including their multidrug resistant (MDR) strains, without any direct assigned function for them. However, yfdX protein along with other proteins involved in acid tolerance response is reported to be up regulated by the multidrug response regulatory system in E. coli. Hence, molecular and functional characterization of this protein is important for understanding of key cellular processes in bacterial cells. Here we study STY3178, a yfdX protein from a MDR strain of typhoid fever causing Salmonella Typhi. Our experimental results indicate that STY3178 is a helical protein existing in a trimeric oligomerization state in solution. We also observe many small antibiotics, like ciprofloxacin, rifampin and ampicillin viably interact with this protein. The dissociation constants from the quenching of steady state fluorescence and isothermal titration calorimetry show that ciprofloxacin binding is stronger than rifampin followed by ampicillin.
Collapse
Affiliation(s)
- Paramita Saha
- Department of Chemical, Biological And Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt lake, Kolkata 700098, India
| | - Camelia Manna
- Department of Chemical, Biological And Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt lake, Kolkata 700098, India
| | - Santasabuj Das
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM Beleghata, Kolkata 700 010, India
| | - Mahua Ghosh
- Department of Chemical, Biological And Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt lake, Kolkata 700098, India
| |
Collapse
|
34
|
Saha P, Sikdar S, Chakrabarti J, Ghosh M. Response to chemical induced changes and their implication in yfdX proteins. RSC Adv 2016. [DOI: 10.1039/c6ra21913f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
|
35
|
Zhou L, Yang L, Zeng X, Danzheng J, Zheng Q, Liu J, Liu F, Xin Y, Cheng X, Su M, Ma Y, Hao X. Transcriptional and proteomic analyses of two-component response regulators in multidrug-resistant Mycobacterium tuberculosis. Int J Antimicrob Agents 2015; 46:73-81. [DOI: 10.1016/j.ijantimicag.2015.02.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 11/28/2022]
|
36
|
AcrB drug-binding pocket substitution confers clinically relevant resistance and altered substrate specificity. Proc Natl Acad Sci U S A 2015; 112:3511-6. [PMID: 25737552 DOI: 10.1073/pnas.1419939112] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The incidence of multidrug-resistant bacterial infections is increasing globally and the need to understand the underlying mechanisms is paramount to discover new therapeutics. The efflux pumps of Gram-negative bacteria have a broad substrate range and transport antibiotics out of the bacterium, conferring intrinsic multidrug resistance (MDR). The genomes of pre- and posttherapy MDR clinical isolates of Salmonella Typhimurium from a patient that failed antibacterial therapy and died were sequenced. In the posttherapy isolate we identified a novel G288D substitution in AcrB, the resistance-nodulation division transporter in the AcrAB-TolC tripartite MDR efflux pump system. Computational structural analysis suggested that G288D in AcrB heavily affects the structure, dynamics, and hydration properties of the distal binding pocket altering specificity for antibacterial drugs. Consistent with this hypothesis, recreation of the mutation in standard Escherichia coli and Salmonella strains showed that G288D AcrB altered substrate specificity, conferring decreased susceptibility to the fluoroquinolone antibiotic ciprofloxacin by increased efflux. At the same time, the substitution increased susceptibility to other drugs by decreased efflux. Information about drug transport is vital for the discovery of new antibacterials; the finding that one amino acid change can cause resistance to some drugs, while conferring increased susceptibility to others, could provide a basis for new drug development and treatment strategies.
Collapse
|
37
|
Sun J, Deng Z, Yan A. Bacterial multidrug efflux pumps: mechanisms, physiology and pharmacological exploitations. Biochem Biophys Res Commun 2014; 453:254-67. [PMID: 24878531 DOI: 10.1016/j.bbrc.2014.05.090] [Citation(s) in RCA: 443] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 05/20/2014] [Indexed: 01/11/2023]
Abstract
Multidrug resistance (MDR) refers to the capability of bacterial pathogens to withstand lethal doses of structurally diverse drugs which are capable of eradicating non-resistant strains. MDR has been identified as a major threat to the public health of human being by the World Health Organization (WHO). Among the four general mechanisms that cause antibiotic resistance including target alteration, drug inactivation, decreased permeability and increased efflux, drug extrusion by the multidrug efflux pumps serves as an important mechanism of MDR. Efflux pumps not only can expel a broad range of antibiotics owing to their poly-substrate specificity, but also drive the acquisition of additional resistance mechanisms by lowering intracellular antibiotic concentration and promoting mutation accumulation. Over-expression of multidrug efflux pumps have been increasingly found to be associated with clinically relevant drug resistance. On the other hand, accumulating evidence has suggested that efflux pumps also have physiological functions in bacteria and their expression is subject tight regulation in response to various of environmental and physiological signals. A comprehensive understanding of the mechanisms of drug extrusion, and regulation and physiological functions of efflux pumps is essential for the development of anti-resistance interventions. In this review, we summarize the development of these research areas in the recent decades and present the pharmacological exploitation of efflux pump inhibitors as a promising anti-drug resistance intervention.
Collapse
Affiliation(s)
- Jingjing Sun
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region
| | - Ziqing Deng
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region
| | - Aixin Yan
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region.
| |
Collapse
|
38
|
Molecular Mechanism of Transcriptional Cascade Initiated by the EvgS/EvgA System inEscherichia coliK-12. Biosci Biotechnol Biochem 2014; 73:870-8. [DOI: 10.1271/bbb.80795] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
39
|
Sevilla E, Alvarez-Ortega C, Krell T, Rojo F. The Pseudomonas putida HskA hybrid sensor kinase responds to redox signals and contributes to the adaptation of the electron transport chain composition in response to oxygen availability. ENVIRONMENTAL MICROBIOLOGY REPORTS 2013; 5:825-834. [PMID: 24249291 DOI: 10.1111/1758-2229.12083] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 06/22/2013] [Indexed: 06/02/2023]
Abstract
Pseudomonas putida has a branched aerobic electron transport that includes five terminal oxidases, each of which has different properties. The relative expression of each oxidase is carefully regulated to assemble the most suitable electron transport chain for the prevailing conditions. The HskA hybrid sensor kinase participates in this control, but the signals to which HskA responds were unknown. Here, the influence of HskA on the mRNA abundance of genes coding for all terminal oxidases and for the bc1 complex was analysed in cells growing under controlled aerobic, semiaerobic or microaerobic conditions. The results indicate that the influence of HskA on the expression of each terminal oxidase and the bc1 complex varies depending on oxygen availability. This effect was more pronounced under aerobic or semiaerobic conditions, but decreased under microaerobic conditions. The expression of hskA was regulated by oxygen availability. We show that HskA autophosphorylation is inhibited by ubiquinone but not by ubiquinol, its reduced derivative. This suggests that HskA could sense the oxidation state of the respiratory ubiquinones, which may be a key factor in HskA activity. Inactivation of hskA reduced growth rate and oxygen consumption, stressing the importance of HskA for the assembly of an efficient electron transport chain.
Collapse
Affiliation(s)
- Emma Sevilla
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Campus UAM, Cantoblanco, 28049, Madrid, Spain
| | | | | | | |
Collapse
|
40
|
YfdW and YfdU are required for oxalate-induced acid tolerance in Escherichia coli K-12. J Bacteriol 2013; 195:1446-55. [PMID: 23335415 DOI: 10.1128/jb.01936-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli has several mechanisms for surviving low-pH stress. We report that oxalic acid, a small-chain organic acid (SCOA), induces a moderate acid tolerance response (ATR) in two ways. Adaptation of E. coli K-12 at pH 5.5 with 50 mM oxalate and inclusion of 25 mM oxalate in pH 3.0 minimal challenge medium separately conferred protection, with 67% ± 7% and 87% ± 17% survival after 2 h, respectively. The combination of oxalate adaptation and oxalate supplementation in the challenge medium resulted in increased survival over adaptation or oxalate in the challenge medium alone. The enzymes YfdW, a formyl coenzyme A (CoA) transferase, and YfdU, an oxalyl-CoA decarboxylase, are required for the adaptation effect but not during challenge. Unlike other SCOAs, this oxalate ATR is not a part of the RpoS regulon but appears to be linked to the signal protein GadE. We theorize that this oxalate ATR could enhance the pathogenesis of virulent E. coli consumed with oxalate-containing foods like spinach.
Collapse
|
41
|
Nicotinic acid modulates Legionella pneumophila gene expression and induces virulence traits. Infect Immun 2013; 81:945-55. [PMID: 23319553 DOI: 10.1128/iai.00999-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In response to environmental fluctuations or stresses, bacteria can activate transcriptional and phenotypic programs to coordinate an adaptive response. The intracellular pathogen Legionella pneumophila converts from a noninfectious replicative form to an infectious transmissive form when the bacterium encounters alterations in either amino acid concentrations or fatty acid biosynthesis. Here, we report that L. pneumophila differentiation is also triggered by nicotinic acid, a precursor of the central metabolite NAD(+). In particular, when replicative L. pneumophila are treated with 5 mM nicotinic acid, the bacteria induce numerous transmissive-phase phenotypes, including motility, cytotoxicity toward macrophages, sodium sensitivity, and lysosome avoidance. Transcriptional profile analysis determined that nicotinic acid induces the expression of a panel of genes characteristic of transmissive-phase L. pneumophila. Moreover, an additional 213 genes specific to nicotinic acid treatment were altered. Although nearly 25% of these genes lack an assigned function, the gene most highly induced by nicotinic acid treatment encodes a putative major facilitator superfamily transporter, Lpg0273. Indeed, lpg0273 protects L. pneumophila from toxic concentrations of nicotinic acid as judged by analyzing the growth of the corresponding mutant. The broad utility of the nicotinic acid pathway to couple central metabolism and cell fate is underscored by this small metabolite's modulation of gene expression by diverse microbes, including Candida glabrata, Bordetella pertussis, Escherichia coli, and L. pneumophila.
Collapse
|
42
|
Effect of acidic condition on the metabolic regulation of Escherichia coli and its phoB mutant. Arch Microbiol 2012; 195:161-71. [DOI: 10.1007/s00203-012-0861-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 12/05/2012] [Accepted: 12/06/2012] [Indexed: 10/27/2022]
|
43
|
Mokracka J, Koczura R, Kaznowski A. Multiresistant Enterobacteriaceae with class 1 and class 2 integrons in a municipal wastewater treatment plant. WATER RESEARCH 2012; 46:3353-63. [PMID: 22507248 DOI: 10.1016/j.watres.2012.03.037] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Revised: 03/08/2012] [Accepted: 03/20/2012] [Indexed: 05/08/2023]
Abstract
In this study, 1832 strains of the family Enterobacteriaceae were isolated from different stages of a municipal wastewater treatment plant, of which 221 (12.1%) were intI-positive. Among them 61.5% originated from raw sewage, 12.7% from aeration tank and 25.8% from the final effluent. All of the intI-positive strains were multiresistant, i.e. resistant to at least three unrelated antimicrobials. Although there were no significant differences in resistance range, defined as the number of antimicrobial classes to which an isolate was resistant, between strains isolated from different stages of wastewater treatment, for five β-lactams the percentage of resistant isolates was the highest in final effluent, which may reflect a selective pressure the bacteria are exposed to, and the possible route of dissemination of β-lactam resistant strains to the corresponding river. The sizes of the variable part of integrons ranged from 0.18 to 3.0 kbp and contained up to four incorporated gene cassettes. Sequence analysis identified over 30 different gene cassettes, including 24 conferring resistance to antibiotics. The highest number of different gene cassettes was found in bacteria isolated from the final effluent. The gene cassettes were arranged in 26 different resistance cassette arrays; the most often were dfrA1-aadA1, aadA1, dfrA17-aadA5 and dfrA12-orfF-aadA2. Regarding the diversity of resistance genes and the number of multiresistant bacteria in the final effluent, we concluded that municipal sewage may serve as a reservoir of integron-embedded antibiotic resistance genes.
Collapse
Affiliation(s)
- Joanna Mokracka
- Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznań, Poznań, Poland.
| | | | | |
Collapse
|
44
|
Nishino K, Yamasaki S, Hayashi-Nishino M, Yamaguchi A. Effect of overexpression of small non-coding DsrA RNA on multidrug efflux in Escherichia coli. J Antimicrob Chemother 2010; 66:291-6. [PMID: 21088020 DOI: 10.1093/jac/dkq420] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Several putative and proven drug efflux pumps are present in Escherichia coli. Because many such efflux pumps have overlapping substrate spectra, it is intriguing that bacteria, with their economically organized genomes, harbour such large sets of multidrug efflux genes. To understand how bacteria utilize these multiple efflux pumps, it is important to elucidate the process of pump expression regulation. The aim of this study was to determine a regulator of the multidrug efflux pump in this organism. METHODS We screened a genomic library of E. coli for genes that decreased drug susceptibility in this organism. The library was developed from the chromosomal DNA of the MG1655 strain, and then the recombinant plasmids were transformed into an acrB-deleted strain. Transformants were screened for resistance to various antibiotics including oxacillin. RESULTS We found that the multidrug susceptibilities of the acrB-deleted strain were decreased by the overexpression of small non-coding DsrA RNA as well as by the overexpression of known regulators of multidrug efflux pumps. Plasmids carrying the dsrA gene conferred resistance to oxacillin, cloxacillin, erythromycin, rhodamine 6G and novobiocin. DsrA decreased the accumulation of ethidium bromide in E. coli cells. Furthermore, expression of mdtE was significantly increased by dsrA overexpression, and the decreased multidrug susceptibilities modulated by DsrA were dependent on the MdtEF efflux pump. CONCLUSIONS These results indicate that DsrA modulates multidrug efflux through activation of genes encoding the MdtEF pump in E. coli.
Collapse
Affiliation(s)
- Kunihiko Nishino
- Laboratory of Microbiology and Infectious Diseases, Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-047, Japan
| | | | | | | |
Collapse
|
45
|
Global transcriptome analysis of the Escherichia coli O157 response to Houttuynia Cordata Thunb. BIOCHIP JOURNAL 2010. [DOI: 10.1007/s13206-010-4312-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
46
|
Baek JH, Han MJ, Lee SY, Yoo JS. Transcriptome and proteome analyses of adaptive responses to methyl methanesulfonate in Escherichia coli K-12 and ada mutant strains. BMC Microbiol 2009; 9:186. [PMID: 19728878 PMCID: PMC2753364 DOI: 10.1186/1471-2180-9-186] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 09/03/2009] [Indexed: 12/03/2022] Open
Abstract
Background The Ada-dependent adaptive response system in Escherichia coli is important for increasing resistance to alkylation damage. However, the global transcriptional and translational changes during this response have not been reported. Here we present time-dependent global gene and protein expression profiles following treatment with methyl methanesulfonate (MMS) in E. coli W3110 and its ada mutant strains. Results Transcriptome profiling showed that 1138 and 2177 genes were differentially expressed in response to MMS treatment in the wild-type and mutant strains, respectively. A total of 81 protein spots representing 76 nonredundant proteins differentially expressed were identified using 2-DE and LC-MS/MS. In the wild-type strain, many genes were differentially expressed upon long-exposure to MMS, due to both adaptive responses and stationary phase responses. In the ada mutant strain, the genes involved in DNA replication, recombination, modification and repair were up-regulated 0.5 h after MMS treatment, indicating its connection to the SOS and other DNA repair systems. Interestingly, expression of the genes involved in flagellar biosynthesis, chemotaxis, and two-component regulatory systems related to drug or antibiotic resistance, was found to be controlled by Ada. Conclusion These results show in detail the regulatory components and pathways controlling adaptive response and how the related genes including the Ada regulon are expressed with this response.
Collapse
Affiliation(s)
- Jong Hwan Baek
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical & Biomolecular Engineering (BK21 Program), BioProcess Engineering Research Center, Center for Systems and Synthetic Biotechnology and Institute for the BioCentury, KAIST, Daejeon, Republic of Korea.
| | | | | | | |
Collapse
|
47
|
Abstract
The gram-negative bacterial envelope is a complex extracytoplasmic compartment responsible for numerous cellular processes. Among its most important functions is its service as the protective layer separating the cytoplasmic space from the ever-changing external environment. To adapt to the diverse conditions encountered both in the environment and within the mammalian host, Escherichia coli and Salmonella species have evolved six independent envelope stress response systems . This review reviews the sE response, the CpxAR and BaeSR two-component systems (TCS) , the phage shock protein response, and the Rcs phosphorelay system. These five signal transduction pathways represent the most studied of the six known stress responses. The signal for adhesion to abiotic surfaces enters the pathway through the novel outer membrane lipoprotein NlpE, and activation on entry into the exponential phase of growth occurs independently of CpxA . Adhesion could disrupt NlpE causing unfolding of its unstable N-terminal domain, leading to activation of the Cpx response. The most recent class of genes added to the Cpx regulon includes those involved in copper homeostasis. Two separate microarray experiments revealed that exposure of E. coli cells to high levels of external copper leads to upregulation of several Cpx regulon members. The BaeSR TCS has also been shown to mediate drug resistance in Salmonella. Similar to E. coli, the Bae pathway of Salmonella enterica mediates resistance to oxacillin, novobiocin, deoxycholate, β-lactams, and indole.
Collapse
|
48
|
Nishino K, Nikaido E, Yamaguchi A. Regulation and physiological function of multidrug efflux pumps in Escherichia coli and Salmonella. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:834-43. [DOI: 10.1016/j.bbapap.2009.02.002] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 02/02/2009] [Accepted: 02/05/2009] [Indexed: 01/30/2023]
|
49
|
Role of the AraC-XylS family regulator YdeO in multi-drug resistance of Escherichia coli. J Antibiot (Tokyo) 2009; 62:251-7. [PMID: 19329985 DOI: 10.1038/ja.2009.23] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Multi-drug efflux pumps contribute to the resistance of Escherichia coli to many antibiotics and biocides. In this study, we report that the AraC-XylS family regulator YdeO increases the multi-drug resistance of E. coli through activation of the MdtEF efflux pump. Screening of random fragments of genomic DNA for their ability to increase beta-lactam resistance led to the isolation of a plasmid containing ydeO, which codes for the regulator of acid resistance. When overexpressed, ydeO significantly increased the resistance of the E. coli strain to oxacillin, cloxacillin, nafcillin, erythromycin, rhodamine 6G and sodium dodecyl sulfate. The increase in drug resistance caused by ydeO overexpression was completely suppressed by deleting the multifunctional outer membrane channel gene tolC. TolC interacts with different drug efflux pumps. Quantitative real-time PCR showed that YdeO activated only mdtEF expression and none of the other drug efflux pumps in E. coli. Deletion of mdtEF completely suppressed the YdeO-mediated multi-drug resistance. YdeO enhances the MdtEF-dependent drug efflux activity in E. coli. Our results indicate that the YdeO regulator, in addition to its role in acid resistance, increases the multi-drug resistance of E. coli by activating the MdtEF multi-drug efflux pump.
Collapse
|
50
|
Eguchi Y, Utsumi R. Introduction to Bacterial Signal Transduction Networks. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 631:1-6. [DOI: 10.1007/978-0-387-78885-2_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|