Absence of mutations in marRAB or soxRS in acrB-overexpressing fluoroquinolone-resistant clinical and veterinary isolates of Escherichia coli.

ABSTRACT: The amount of acrB, marA, and soxS mRNA was determined in 36 fluoroquinolone-resistant E. coli from humans and animals, 27 of which displayed a multiple-resistance phenotype. acrB mRNA was elevated in 11 of 36 strains. A mutation at codon 45 (Arg-->Cys) in acrR was found in 6 of these 11 strains. Ten of the 36 isolates appeared to overexpress soxS, and five appeared to overexpress marA. A number of mutations were found in the marR and soxR repressor genes, correlating with greater amounts of marA and soxS mRNA, respectively.

SUBMITTER: Webber MA 

PROVIDER: S-EPMC90504 | biostudies-literature | 2001 May

REPOSITORIES: biostudies-literature