American Society for Microbiology, Antimicrobial Agents and Chemotherapy, 4(61), 2017
DOI: 10.1128/aac.02615-16
Full text: Unavailable
ABSTRACT Escherichia coli variants expressing plasmid-mediated qnr genes are usually susceptible to fluoroquinolones by standard susceptibility testing. Here we show that, under specific urinary tract physiological conditions, susceptible laboratory and clinical strains harboring qnr determinants become fully resistant to ciprofloxacin (CIP). Therefore, physiological conditions, mainly urine pH values, should be considered when performing susceptibility testing of CIP activity against E. coli in treating urinary tract infection (UTI) and for selecting appropriate antibiotics for UTI treatment.