Contribution of mutation at amino acid 45 of AcrR to acrB expression and ciprofloxacin resistance in clinical and veterinary Escherichia coli isolates.
نویسندگان
چکیده
Fluoroquinolone-resistant Escherichia coli isolates which overexpressed acrB and had a substitution at amino acid 45 of AcrR were complemented with wild-type acrR. Complementation led to increased sensitivity to ciprofloxacin and to ethidium bromide, suggesting that mutation at amino acid 45 of AcrR contributes to ciprofloxacin resistance.
منابع مشابه
Expression of acrA and acrB Genes in Esherichia coli Mutants with or without marR or acrR Mutations
Objective(s): The major antibiotic efflux pump of Esherichia coli is AcrAB-TolC. The first part of the pump, AcrAB, is encoded by acrAB operon. The expression of this operon can be kept elevated by overexpression of an activator, MarA following inactivation of MarR and AcrR repressors due to mutation in encoding genes, marR and acrR, respectively. The aims of this research were to us...
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متن کاملStudy of Mutations in the DNA gyrase gyrA Gene of Escherichia coli
Quinolones are a large and widely consumed class of synthetic drugs. Expanded-spectrum quinolones, like ciprofloxacin are highly effective against Gram-negative bacteria, especially Escherichia coli. In E. coli the major target for quinolones is DNA gyrase. This enzyme is composed of two subunits, GyrA and GyrB encoding by gyrA and gyrB, respectively. Mutations in either of these genes cause qu...
متن کاملExpression of acrA and acrB Genes in Esherichia coli Mutants with or without marR or acrR Mutations
OBJECTIVE(S) The major antibiotic efflux pump of Esherichia coli is AcrAB-TolC. The first part of the pump, AcrAB, is encoded by acrAB operon. The expression of this operon can be kept elevated by overexpression of an activator, MarA following inactivation of MarR and AcrR repressors due to mutation in encoding genes, marR and acrR, respectively. The aims of this research were to use E. coli mu...
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ورودعنوان ژورنال:
- Antimicrobial agents and chemotherapy
دوره 49 10 شماره
صفحات -
تاریخ انتشار 2005