Activity of faropenem and imipenem for ciprofloxacin-resistant bacteria.

AIM To determine whether an association exists between ciprofloxacin and faropenem resistance in bacteria including multiply drug-resistant isolates. METHODS The MICs were determined for 150 fluoroquinolone-resistant bacteria, plus 20 nalidixic acid-resistant strains of Salmonella enterica serovar Typhimurium. RESULTS Faropenem was very active against Escherichia coli and Streptococcus pneumoniae, but 5/31 Staphylococcus aureus and 2/26 Bacteroides fragilis required > or =16 mg/L for inhibition. Of 30 multiply drug-resistant isolates with a phenotype suggestive of enhanced efflux, only for one strain (a Bacteroides fragilis) was the faropenem MIC higher than that associated with the other isolates of the same species. CONCLUSIONS Faropenem was in general as active as imipenem. There was no association between resistance to ciprofloxacin and faropenem or imipenem resistance.