Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Functional and Genetic Characterization of the Tap Efflux Pump in Mycobacterium bovis BCG

Functional and Genetic Characterization of the Tap Efflux Pump in Mycobacterium bovis BCG Functional and Genetic Characterization of the Tap Efflux Pump in Mycobacterium bovis BCG Santiago Ramón-García a , b , Virginie Mick a , Elisa Dainese c , Carlos Martín a , Charles J. Thompson b , Edda De Rossi d , Riccardo Manganelli c and José A. Aínsa a a Departamento de Microbiología, Medicina Preventiva y Salud Pública, Universidad de Zaragoza, Zaragoza, Spain, and CIBER Enfermedades Respiratorias ‡ b Department of Microbiology and Immunology and Centre for Tuberculosis Research, Life Sciences Centre, University of British Columbia, Vancouver, British Columbia, Canada c Department of Histology, Microbiology, and Medical Biotechnologies, University of Padova, Padova, Italy d Dipartimento di Genetica e Microbiologia, Università degli Studi di Pavia, Pavia, Italy ABSTRACT Efflux pumps extrude a wide variety of chemically unrelated compounds conferring multidrug resistance and participating in numerous physiological processes. Mycobacterium tuberculosis possesses many efflux pumps, and their roles in drug resistance and physiology are actively investigated. In this work we found that tap mutant cells showed changes in morphology and a progressive loss of viability upon subcultivation in liquid medium. Transcriptome analysis in Mycobacterium bovis BCG revealed that disruption of the Rv1258c gene, encoding the Tap efflux pump, led to an extensive change in gene expression patterns during stationary phase, with no changes during exponential growth. In stationary phase, Tap inactivation triggered a general stress response and led to a general repression of genes involved in cell wall biosynthesis, in particular the formation of the peptidoglycan; this suggested the accumulation of an unknown Tap substrate that reaches toxic concentrations during stationary phase. We also found that both disruption and overexpression of tap altered susceptibility to many clinically approved antibiotics in M. bovis BCG. Acriflavine and tetracycline accumulation assays and carbonyl cyanide m -chlorophenylhydrazone (CCCP) potentiation experiments demonstrated that this phenotype was due to an active efflux mechanism. These findings emphasize the important role of the Tap efflux pump in bacterial physiology and intrinsic drug resistance. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Antimicrobial Agents and Chemotherapy American Society For Microbiology

Functional and Genetic Characterization of the Tap Efflux Pump in Mycobacterium bovis BCG

Functional and Genetic Characterization of the Tap Efflux Pump in Mycobacterium bovis BCG

Antimicrobial Agents and Chemotherapy , Volume 56 (4): 2074 – Apr 1, 2012

Abstract

Functional and Genetic Characterization of the Tap Efflux Pump in Mycobacterium bovis BCG Santiago Ramón-García a , b , Virginie Mick a , Elisa Dainese c , Carlos Martín a , Charles J. Thompson b , Edda De Rossi d , Riccardo Manganelli c and José A. Aínsa a a Departamento de Microbiología, Medicina Preventiva y Salud Pública, Universidad de Zaragoza, Zaragoza, Spain, and CIBER Enfermedades Respiratorias ‡ b Department of Microbiology and Immunology and Centre for Tuberculosis Research, Life Sciences Centre, University of British Columbia, Vancouver, British Columbia, Canada c Department of Histology, Microbiology, and Medical Biotechnologies, University of Padova, Padova, Italy d Dipartimento di Genetica e Microbiologia, Università degli Studi di Pavia, Pavia, Italy ABSTRACT Efflux pumps extrude a wide variety of chemically unrelated compounds conferring multidrug resistance and participating in numerous physiological processes. Mycobacterium tuberculosis possesses many efflux pumps, and their roles in drug resistance and physiology are actively investigated. In this work we found that tap mutant cells showed changes in morphology and a progressive loss of viability upon subcultivation in liquid medium. Transcriptome analysis in Mycobacterium bovis BCG revealed that disruption of the Rv1258c gene, encoding the Tap efflux pump, led to an extensive change in gene expression patterns during stationary phase, with no changes during exponential growth. In stationary phase, Tap inactivation triggered a general stress response and led to a general repression of genes involved in cell wall biosynthesis, in particular the formation of the peptidoglycan; this suggested the accumulation of an unknown Tap substrate that reaches toxic concentrations during stationary phase. We also found that both disruption and overexpression of tap altered susceptibility to many clinically approved antibiotics in M. bovis BCG. Acriflavine and tetracycline accumulation assays and carbonyl cyanide m -chlorophenylhydrazone (CCCP) potentiation experiments demonstrated that this phenotype was due to an active efflux mechanism. These findings emphasize the important role of the Tap efflux pump in bacterial physiology and intrinsic drug resistance.

Loading next page...
 
/lp/american-society-for-microbiology/functional-and-genetic-characterization-of-the-tap-efflux-pump-in-saGY9Yq7A8

References (66)

Publisher
American Society For Microbiology
Copyright
Copyright © 2012 by the American society for Microbiology.
ISSN
0066-4804
eISSN
1098-6596
DOI
10.1128/AAC.05946-11
pmid
22232275
Publisher site
See Article on Publisher Site

Abstract

Functional and Genetic Characterization of the Tap Efflux Pump in Mycobacterium bovis BCG Santiago Ramón-García a , b , Virginie Mick a , Elisa Dainese c , Carlos Martín a , Charles J. Thompson b , Edda De Rossi d , Riccardo Manganelli c and José A. Aínsa a a Departamento de Microbiología, Medicina Preventiva y Salud Pública, Universidad de Zaragoza, Zaragoza, Spain, and CIBER Enfermedades Respiratorias ‡ b Department of Microbiology and Immunology and Centre for Tuberculosis Research, Life Sciences Centre, University of British Columbia, Vancouver, British Columbia, Canada c Department of Histology, Microbiology, and Medical Biotechnologies, University of Padova, Padova, Italy d Dipartimento di Genetica e Microbiologia, Università degli Studi di Pavia, Pavia, Italy ABSTRACT Efflux pumps extrude a wide variety of chemically unrelated compounds conferring multidrug resistance and participating in numerous physiological processes. Mycobacterium tuberculosis possesses many efflux pumps, and their roles in drug resistance and physiology are actively investigated. In this work we found that tap mutant cells showed changes in morphology and a progressive loss of viability upon subcultivation in liquid medium. Transcriptome analysis in Mycobacterium bovis BCG revealed that disruption of the Rv1258c gene, encoding the Tap efflux pump, led to an extensive change in gene expression patterns during stationary phase, with no changes during exponential growth. In stationary phase, Tap inactivation triggered a general stress response and led to a general repression of genes involved in cell wall biosynthesis, in particular the formation of the peptidoglycan; this suggested the accumulation of an unknown Tap substrate that reaches toxic concentrations during stationary phase. We also found that both disruption and overexpression of tap altered susceptibility to many clinically approved antibiotics in M. bovis BCG. Acriflavine and tetracycline accumulation assays and carbonyl cyanide m -chlorophenylhydrazone (CCCP) potentiation experiments demonstrated that this phenotype was due to an active efflux mechanism. These findings emphasize the important role of the Tap efflux pump in bacterial physiology and intrinsic drug resistance.

Journal

Antimicrobial Agents and ChemotherapyAmerican Society For Microbiology

Published: Apr 1, 2012

There are no references for this article.