title: Functional role of bacterial multidrug efflux pumps in microbial natural ecosystems.
abstract: Multidrug efflux pumps have emerged as relevant elements in the intrinsic and acquired antibiotic resistance of bacterial pathogens. In contrast with other antibiotic resistance genes that have been obtained by virulent bacteria through horizontal gene transfer, genes coding for multidrug efflux pumps are present in the chromosomes of all living organisms. In addition, these genes are highly conserved (all members of the same species contain the same efflux pumps) and their expression is tightly regulated. Together, these characteristics suggest that the main function of these systems is not resisting the antibiotics used in therapy and that they should have other roles relevant to the behavior of bacteria in their natural ecosystems. Among the potential roles, it has been demonstrated that efflux pumps are important for processes of detoxification of intracellular metabolites, bacterial virulence in both animal and plant hosts, cell homeostasis and intercellular signal trafficking.
authors.affiliation: Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Cantoblanco, Madrid, Spain. jlmtnez@cnb.csic.es
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Martinez
authors.forename: María Blanca
authors.initials: MB
authors.lastname: Sánchez
authors.forename: Laura
authors.initials: L
authors.lastname: Martínez-Solano
authors.forename: Alvaro
authors.initials: A
authors.lastname: Hernandez
authors.forename: Leonor
authors.initials: L
authors.lastname: Garmendia
authors.forename: Alicia
authors.initials: A
authors.lastname: Fajardo
authors.forename: Carolina
authors.initials: C
authors.lastname: Alvarez-Ortega
mesh_terms: D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000472:pathogenicity; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial; D017753:Ecosystem; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D019216:Metals, Heavy / Q000494:pharmacology; D010935:Plant Diseases / Q000382:microbiology; D010944:Plants / Q000382:microbiology*; D053038:Quorum Sensing; D015398:Signal Transduction; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D019216:Metals, Heavy