title: AcrAB Efflux System: Expression and Contribution to Fluoroquinolone Resistance in Klebsiella spp.
abstract: Seven Klebsiella pneumoniae and four Klebsiella oxytoca clinical isolates with different levels of resistance to ciprofloxacin were studied. Mutations in the topoisomerase genes were found in almost all strains, but the contribution of a multidrug efflux system homologous to AcrAB in Escherichia coli was also observed. Overexpression of this efflux system was demonstrated by immunoblotting with antibodies against E. coli AcrA.
authors.affiliation: Dipartimento di Patologia, Sezione di Microbiologia, Università di Verona, Italy. annarita.mazzariol@univr.it
authors.forename: Annarita
authors.initials: A
authors.lastname: Mazzariol
authors.forename: Jessica
authors.initials: J
authors.lastname: Zuliani
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cornaglia
authors.forename: Gian Maria
authors.initials: GM
authors.lastname: Rossolini
authors.forename: Roberta
authors.initials: R
authors.lastname: Fontana
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000378:metabolism / Q000494:pharmacology; D004264:DNA Topoisomerases, Type I / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D041121:Klebsiella oxytoca / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests
chemical_list: D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D004264:DNA Topoisomerases, Type I