Low-level resistance to the cephalosporin 3'-quinolone ester Ro 23-9424 in Escherichia coli.
Four spontaneous, single-step mutants of Escherichia coli K-12 resistant to low levels of the cephalosporin 3'-quinolone ester Ro 23-9424 were isolated at a frequency of 10(-10) to 10(-11) mutants per CFU plated. The mutants were cross-resistant to both cephalosporin (cefotaxime) and quinolone (fleroxacin) components. Accordingly, they had altered porins and replicative DNA biosynthesis resistant to fleroxacin. There was no increase in beta-lactamase activity when tested with nitrocephin, and the penicillin-binding protein profiles were normal.
Chapman
J S
JS
Roche Research Center, Nutley, New Jersey 07110, USA.
Bertasso
A
A
Cummings
L M
LM
Georgopapadakou
N H
NH
D000890:Anti-Infective Agents / Q000494:pharmacology*; D002439:Cefotaxime / Q000031:analogs & derivatives* / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects*; D016576:Fleroxacin / Q000031:analogs & derivatives* / Q000494:pharmacology; D024841:Fluoroquinolones; D008826:Microbial Sensitivity Tests
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; C060441:Ro-23-9424; D002439:Cefotaxime; D016576:Fleroxacin