Increased expression of ampC in Pseudomonas aeruginosa mutants selected with ciprofloxacin.
Two Pseudomonas aeruginosa mutants exhibiting increased expression of ampC were selected during exposure to ciprofloxacin. These mutants also exhibited significant increases in mexCD-oprJ expression, but further studies failed to show a link between the increased expression of mexCD-oprJ and ampC. Increased ampC expression was not related to mutations within ampR, the ampC-ampR intergenic region, ampD, ampDh2, or ampDh3 or to changes in the levels of expression of these amidase genes. However, ampD complementation restored wild-type levels of ampC expression and ceftazidime susceptibility, suggesting alternative mechanisms of ampC regulation.
Wolter
Daniel J
DJ
Center for Research in Anti-Infectives and Biotechnology, Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA.
Schmidtke
Amber J
AJ
Hanson
Nancy D
ND
Lister
Philip D
PD
D000890:Anti-Infective Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002939:Ciprofloxacin / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D015854:Up-Regulation; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D002939:Ciprofloxacin; C048795:AmpC beta-lactamases; D001618:beta-Lactamases