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Escalante J, Hamza M, Nishimura B, Melecio M, Davies-Sala C, Tuttobene MR, Subils T, Traglia GM, Pham C, Sieira R, Actis LA, Bonomo RA, Tolmasky ME, Ramirez MS. Carbapenem-resistant Acinetobacter baumannii (CRAB): metabolic adaptation and transcriptional response to human urine (HU). Sci Rep 2024; 14:19145. [PMID: 39160175 PMCID: PMC11333713 DOI: 10.1038/s41598-024-70216-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Accepted: 08/13/2024] [Indexed: 08/21/2024] Open
Abstract
Carbapenem-resistant Acinetobacter baumannii (CRAB) is a major human pathogen and a research priority for developing new antimicrobial agents. CRAB is a causative agent of a variety of infections in different body sites. One of the manifestations is catheter-associated urinary tract infection, which exposes the bacteria to the host's urine, creating a particular environment. Exposure of two CRAB clinical isolates, AB5075 and AMA40, to human urine (HU) resulted in the differential expression levels of 264 and 455 genes, respectively, of which 112 were common to both strains. Genes within this group play roles in metabolic pathways such as phenylacetic acid (PAA) catabolism, the Hut system, the tricarboxylic acid (TCA) cycle, and other processes like quorum sensing and biofilm formation. These results indicate that the presence of HU induces numerous adaptive changes in gene expression of the infecting bacteria. These changes presumably help bacteria establish and thrive in the hostile conditions in the urinary tract. These analyses advance our understanding of CRAB's metabolic adaptations to human fluids, as well as expand knowledge on bacterial responses to distinct human fluids containing different concentrations of human serum albumin (HSA).
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Affiliation(s)
- Jenny Escalante
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, USA
| | - Mase Hamza
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, USA
| | - Brent Nishimura
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, USA
| | - Meghan Melecio
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, USA
| | - Carol Davies-Sala
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, USA
| | - Marisel R Tuttobene
- Área Biología Molecular, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina
| | - Tomás Subils
- Instituto de Procesos Biotecnológicos y Químicos de Rosario (IPROBYQ, CONICET-UNR), Rosario, Argentina
| | - German M Traglia
- Unidad de Genómica y Bioinformática, Departamento de Ciencias Biológicas, CENUR Litoral Norte, Universidad de la República, Montevideo, Uruguay
| | - Chloe Pham
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, USA
| | - Rodrigo Sieira
- Fundación Instituto Leloir-IIBBA CONICET, Buenos Aires, Argentina
| | - Luis A Actis
- Department of Microbiology, Miami University, Oxford, Ohio, USA
| | - Robert A Bonomo
- Research Service and GRECC, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA
- Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Biochemistry, Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH, USA
| | - Marcelo E Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, USA
| | - María Soledad Ramirez
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, USA.
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2
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Escalante J, Hamza M, Nishimura B, Melecio M, Davies-Sala C, Tuttobene MR, Subils T, Traglia GM, Pham C, Sieira R, Actis L, Bonomo RA, Tolmasky ME, Ramirez MS. Carbapenem-resistant Acinetobacter baumannii (CRAB): metabolic adaptation and transcriptional response to human urine (HU). RESEARCH SQUARE 2024:rs.3.rs-4415275. [PMID: 38853891 PMCID: PMC11160873 DOI: 10.21203/rs.3.rs-4415275/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Carbapenem-resistant Acinetobacter baumannii (CRAB) is a major human pathogen and a research priority for developing new antimicrobial agents. CRAB is a causative agent of a variety of infections in different body sites. One of the manifestations is catheter-associated urinary tract infection, which exposes the bacteria to the host's urine, creating a particular environment. Exposure of two CRAB clinical isolates, AB5075 and AMA40, to human urine (HU) resulted in the differential expression levels of 264 and 455 genes, respectively, of which 112 were common to both strains. Genes within this group play roles in metabolic pathways such as phenylacetic acid (PAA) catabolism, the Hut system, the tricarboxylic acid (TCA) cycle, and other processes like quorum sensing and biofilm formation. These results indicate that the presence of HU induces numerous adaptive changes in gene expression of the infecting bacteria. These modifications presumably help bacteria establish and thrive in the hostile conditions in the urinary tract. These analyses advance our understanding of CRAB's metabolic adaptations to human fluids, as well as expanding knowledge on bacterial responses to distinct human fluids containing different concentrations of human serum albumin (HSA).
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3
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Menon ND, Poudel S, Sastry AV, Rychel K, Szubin R, Dillon N, Tsunemoto H, Hirose Y, Nair BG, Kumar GB, Palsson BO, Nizet V. Independent component analysis reveals 49 independently modulated gene sets within the global transcriptional regulatory architecture of multidrug-resistant Acinetobacter baumannii. mSystems 2024; 9:e0060623. [PMID: 38189271 PMCID: PMC10878099 DOI: 10.1128/msystems.00606-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 11/29/2023] [Indexed: 01/09/2024] Open
Abstract
Acinetobacter baumannii causes severe infections in humans, resists multiple antibiotics, and survives in stressful environmental conditions due to modulations of its complex transcriptional regulatory network (TRN). Unfortunately, our global understanding of the TRN in this emerging opportunistic pathogen is limited. Here, we apply independent component analysis, an unsupervised machine learning method, to a compendium of 139 RNA-seq data sets of three multidrug-resistant A. baumannii international clonal complex I strains (AB5075, AYE, and AB0057). This analysis allows us to define 49 independently modulated gene sets, which we call iModulons. Analysis of the identified A. baumannii iModulons reveals validating parallels to previously defined biological operons/regulons and provides a framework for defining unknown regulons. By utilizing the iModulons, we uncover potential mechanisms for a RpoS-independent general stress response, define global stress-virulence trade-offs, and identify conditions that may induce plasmid-borne multidrug resistance. The iModulons provide a model of the TRN that emphasizes the importance of transcriptional regulation of virulence phenotypes in A. baumannii. Furthermore, they suggest the possibility of future interventions to guide gene expression toward diminished pathogenic potential.IMPORTANCEThe rise in hospital outbreaks of multidrug-resistant Acinetobacter baumannii infections underscores the urgent need for alternatives to traditional broad-spectrum antibiotic therapies. The success of A. baumannii as a significant nosocomial pathogen is largely attributed to its ability to resist antibiotics and survive environmental stressors. However, there is limited literature available on the global, complex regulatory circuitry that shapes these phenotypes. Computational tools that can assist in the elucidation of A. baumannii's transcriptional regulatory network architecture can provide much-needed context for a comprehensive understanding of pathogenesis and virulence, as well as for the development of targeted therapies that modulate these pathways.
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Affiliation(s)
- Nitasha D. Menon
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kerala, India
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Saugat Poudel
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Anand V. Sastry
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Kevin Rychel
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Richard Szubin
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Nicholas Dillon
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Biological Sciences, University of Texas at Dallas, Dallas, Texas, USA
| | - Hannah Tsunemoto
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA
| | - Yujiro Hirose
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Microbiology, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan
| | - Bipin G. Nair
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kerala, India
| | - Geetha B. Kumar
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kerala, India
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Victor Nizet
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
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4
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König P, Averhoff B, Müller V. K + homeostasis is important for survival of Acinetobacter baumannii ATCC 19606 in the nosocomial environment. Int Microbiol 2024; 27:303-310. [PMID: 37338636 PMCID: PMC10830791 DOI: 10.1007/s10123-023-00389-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/24/2023] [Accepted: 06/05/2023] [Indexed: 06/21/2023]
Abstract
Pathogenic bacteria have developed several mechanisms to thrive within the hostile environment of the human host, but it is often disregarded that their survival outside this niche is crucial for their successful transmission. Acinetobacter baumannii is very well adapted to both the human host and the hospital environment. The latter is facilitated by multifactorial mechanisms including its outstanding ability to survive on dry surfaces, its high metabolic diversity, and, of course, its remarkable osmotic resistance. As a first response to changing osmolarities, bacteria accumulate K+ in high amount to counterbalance the external ionic strength. Here, we addressed whether K+ uptake is involved in the challenges imposed by the harsh conditions outside its host and how K+ import influences the antibiotic resistance of A. baumannii. For this purpose, we used a strain lacking all major K+ importer ∆kup∆trk∆kdp. Survival of this mutant was strongly impaired under nutrient limitation in comparison to the wild type. Furthermore, we found that not only the resistance against copper but also against the disinfectant chlorhexidine was reduced in the triple mutant compared to the wild type. Finally, we revealed that the triple mutant is highly susceptible to a broad range of antibiotics and antimicrobial peptides. By studying mutants, in which the K+ transporter were deleted individually, we provide evidence that this effect is a consequence of the altered K+ uptake machinery. Conclusively, this study provides supporting information on the relevance of K+ homeostasis in the adaptation of A. baumannii to the nosocomial environment.
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Affiliation(s)
- Patricia König
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany
| | - Beate Averhoff
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany.
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Hubloher JJ, van der Sande L, Müller V. Na + homeostasis in Acinetobacter baumannii is facilitated via the activity of the Mrp antiporter. Environ Microbiol 2022; 24:4411-4424. [PMID: 35535800 DOI: 10.1111/1462-2920.16039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/26/2022] [Accepted: 05/04/2022] [Indexed: 11/30/2022]
Abstract
The human opportunistic pathogen Acinetobacter baumannii is a global threat to healthcare institutions worldwide, since it developed very efficient strategies to evade host defense and to adapt to the different environmental conditions of the host. This worked focused on the importance of Na+ homeostasis in A. baumannii with regards to pathobiological aspects. In silico studies revealed a homologue of a multicomponent Na+ /H+ antiporter system. Inactivation of the Mrp antiporter through deletion of the first gene (mrpA') resulted in a mutant that was sensitive to increasing pH values. Furthermore, the strain was highly sensitive to increasing Na+ and Li+ concentrations. Increasing Na+ sensitivity is thought to be responsible for growth impairment in human fluids. Furthermore, deletion of mrpA' is associated with energetic defects, inhibition of motility and survival under anoxic and dry conditions.
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Affiliation(s)
- Josephine Joy Hubloher
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
| | - Lisa van der Sande
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
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Abstract
Potassium is an essential mineral nutrient required by all living cells for normal physiological function. Therefore, maintaining intracellular potassium homeostasis during bacterial infection is a requirement for the survival of both host and pathogen. However, pathogenic bacteria require potassium transport to fulfill nutritional and chemiosmotic requirements, and potassium has been shown to directly modulate virulence gene expression, antimicrobial resistance, and biofilm formation. Host cells also require potassium to maintain fundamental biological processes, such as renal function, muscle contraction, and neuronal transmission; however, potassium flux also contributes to critical immunological and antimicrobial processes, such as cytokine production and inflammasome activation. Here, we review the role and regulation of potassium transport and signaling during infection in both mammalian and bacterial cells and highlight the importance of potassium to the success and survival of each organism.
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Kashyap S, Sharma P, Capalash N. Potential genes associated with survival of Acinetobacter baumannii under ciprofloxacin stress. Microbes Infect 2021; 23:104844. [PMID: 34098109 DOI: 10.1016/j.micinf.2021.104844] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/14/2021] [Accepted: 05/22/2021] [Indexed: 11/25/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen that has acquired resistance to all available drugs. The rise in multi-drug resistance in A. baumannii has been exacerbated by its ability to tolerate antibiotics due to the persister cells, which are phenotypic variants of normal cells that can survive various stress conditions, resulting in chronicity of infection. In the present study we observed that A. baumannii formed persister cells against lethal concentration of ciprofloxacin in exponential phase. The transcriptome of A. baumannii was analyzed after exposure to high concentration of ciprofloxacin (50X MIC) to determine the possible mechanisms of survival. Transcriptome analysis showed differential expression of 146 genes, of which 101 were up-regulated and 45 were down-regulated under ciprofloxacin stress. Differentially expressed genes that might be important for persistence against ciprofloxacin were involved in DNA repair, phenylacetic acid degradation, leucine catabolism, HicAB toxin-antitoxin system and ROS response (iron-sulfur clusters, hemerythrin-like metal binding and Kdp). recA, umuD and ddrR genes involved in SOS response were also up-regulated. Knockout of umuD showed significant decrease in persister cells formation while they were completely eradicated in recA mutant strain. The differentially expressed genes highlighted in the study merit further investigation as therapeutic targets for effective control of A. baumannii infections.
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Affiliation(s)
- Shruti Kashyap
- Department of Biotechnology, Panjab University, BMS Block-I, Sector-25, Chandigarh, India, 160014
| | - Prince Sharma
- Department of Microbiology, Panjab University, BMS Block-I, Sector-25, Chandigarh, India, 160014
| | - Neena Capalash
- Department of Biotechnology, Panjab University, BMS Block-I, Sector-25, Chandigarh, India, 160014.
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8
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Stautz J, Hellmich Y, Fuss MF, Silberberg JM, Devlin JR, Stockbridge RB, Hänelt I. Molecular Mechanisms for Bacterial Potassium Homeostasis. J Mol Biol 2021; 433:166968. [PMID: 33798529 DOI: 10.1016/j.jmb.2021.166968] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/11/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022]
Abstract
Potassium ion homeostasis is essential for bacterial survival, playing roles in osmoregulation, pH homeostasis, regulation of protein synthesis, enzyme activation, membrane potential adjustment and electrical signaling. To accomplish such diverse physiological tasks, it is not surprising that a single bacterium typically encodes several potassium uptake and release systems. To understand the role each individual protein fulfills and how these proteins work in concert, it is important to identify the molecular details of their function. One needs to understand whether the systems transport ions actively or passively, and what mechanisms or ligands lead to the activation or inactivation of individual systems. Combining mechanistic information with knowledge about the physiology under different stress situations, such as osmostress, pH stress or nutrient limitation, one can identify the task of each system and deduce how they are coordinated with each other. By reviewing the general principles of bacterial membrane physiology and describing the molecular architecture and function of several bacterial K+-transporting systems, we aim to provide a framework for microbiologists studying bacterial potassium homeostasis and the many K+-translocating systems that are still poorly understood.
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Affiliation(s)
- Janina Stautz
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Yvonne Hellmich
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Michael F Fuss
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jakob M Silberberg
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jason R Devlin
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Randy B Stockbridge
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States.
| | - Inga Hänelt
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany.
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Wang X, Cai X, Ma H, Yin W, Zhu L, Li X, Lim HM, Chou SH, He J. A c-di-AMP riboswitch controlling kdpFABC operon transcription regulates the potassium transporter system in Bacillus thuringiensis. Commun Biol 2019; 2:151. [PMID: 31044176 PMCID: PMC6488665 DOI: 10.1038/s42003-019-0414-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 03/28/2019] [Indexed: 11/09/2022] Open
Abstract
The intracellular K+ level in bacteria is strictly controlled by K+ uptake and efflux systems. Among these, KdpFABC is a high-affinity K+ transporter system that is generally activated by the KdpDE two-component system in response to K+ limitation stress. However, the regulatory mechanism remains obscure in bacteria lacking the kdpDE genes. Here we report that the transcription of a kdpFABC operon is distinctively regulated by a cyclic diadenylate monophosphate (c-di-AMP) riboswitch located at the 5'-untranslated region of kdp transcript, and binding of c-di-AMP to the riboswitch promotes its intrinsic termination that blocks the kdpFABC transcription. Further, the intracellular c-di-AMP concentration was found to decrease under the K+ limitation stress, leading to transcriptional read-through over the terminator to allow kdpFABC expression. This regulatory element is found predominantly in the Bacillus cereus group and correlate well with the K+ and c-di-AMP homeostasis that affects a variety of crucial cellular functions.
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Affiliation(s)
- Xun Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Xia Cai
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Hongdan Ma
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Wen Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Li Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Heon M. Lim
- Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon, 305-764 Republic of Korea
| | - Shan-Ho Chou
- Institute of Biochemistry and Agricultural Biotechnology Center, National Chung Hsing University, Taichung, 40227 Taiwan
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
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10
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Bhagirath AY, Li Y, Patidar R, Yerex K, Ma X, Kumar A, Duan K. Two Component Regulatory Systems and Antibiotic Resistance in Gram-Negative Pathogens. Int J Mol Sci 2019; 20:E1781. [PMID: 30974906 PMCID: PMC6480566 DOI: 10.3390/ijms20071781] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 12/17/2022] Open
Abstract
Gram-negative pathogens such as Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa are the leading cause of nosocomial infections throughout the world. One commonality shared among these pathogens is their ubiquitous presence, robust host-colonization and most importantly, resistance to antibiotics. A significant number of two-component systems (TCSs) exist in these pathogens, which are involved in regulation of gene expression in response to environmental signals such as antibiotic exposure. While the development of antimicrobial resistance is a complex phenomenon, it has been shown that TCSs are involved in sensing antibiotics and regulating genes associated with antibiotic resistance. In this review, we aim to interpret current knowledge about the signaling mechanisms of TCSs in these three pathogenic bacteria. We further attempt to answer questions about the role of TCSs in antimicrobial resistance. We will also briefly discuss how specific two-component systems present in K. pneumoniae, A. baumannii, and P. aeruginosa may serve as potential therapeutic targets.
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Affiliation(s)
- Anjali Y Bhagirath
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Yanqi Li
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Rakesh Patidar
- Department of Microbiology, Faculty of Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Katherine Yerex
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Xiaoxue Ma
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Ayush Kumar
- Department of Microbiology, Faculty of Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Kangmin Duan
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
- Department of Medical Microbiology & Infectious Diseases, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
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11
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Ali MK, Li X, Tang Q, Liu X, Chen F, Xiao J, Ali M, Chou SH, He J. Regulation of Inducible Potassium Transporter KdpFABC by the KdpD/KdpE Two-Component System in Mycobacterium smegmatis. Front Microbiol 2017; 8:570. [PMID: 28484428 PMCID: PMC5401905 DOI: 10.3389/fmicb.2017.00570] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/20/2017] [Indexed: 12/28/2022] Open
Abstract
Kdp-ATPase is an inducible high affinity potassium uptake system that is widely distributed in bacteria, and is generally regulated by the KdpD/KdpE two-component system (TCS). In this study, conducted on Mycobacterium smegmatis, the kdpFABC (encoding Kdp-ATPase) expression was found to be affected by low concentration of K+, high concentrations of Na+, and/or [Formula: see text] of the medium. The KdpE was found to be a transcriptional regulator that bound to a specific 22-bp sequence in the promoter region of kdpFABC operon to positively regulate kdpFABC expression. The KdpE binding motif was highly conserved in the promoters of kdpFABC among the mycobacterial species. 5'-RACE data indicated a transcriptional start site (TSS) of the kdpFABC operon within the coding sequence of MSMEG_5391, which comprised a 120-bp long 5'-UTR and an open reading frame of the 87-bp kdpF gene. The kdpE deletion resulted in altered growth rate under normal and low K+ conditions. Furthermore, under K+ limiting conditions, a single transcript (kdpFABCDE) spanning kdpFABC and kdpDE operons was observed. This study provided the first insight into the regulation of kdpFABC operon by the KdpD/KdpE TCS in M. smegmatis.
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Affiliation(s)
- Maria K Ali
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Qing Tang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Xiaoyu Liu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Fang Chen
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Jinfeng Xiao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Muhammad Ali
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China.,Biotechnology Program, Department of Environmental Sciences, COMSATS Institute of Information TechnologyAbbottabad, Pakistan
| | - Shan-Ho Chou
- Institute of Biochemistry and NCHU Agricultural Biotechnology Center, National Chung Hsing UniversityTaichung, Taiwan
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China
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