Outer membrane protein profiles of clonally related Klebsiella pneumoniae isolates that differ in cefoxitin resistance.
Eleven genotypically related Klebsiella pneumoniae isolates were obtained from 11 patients. All isolates were resistant to third-generation cephalosporins due to the production of SHV-2a extended-spectrum beta-lactamase. Comparison of the outer membrane protein profiles revealed one isolate that lacked porins. This porin-deficient isolate was also resistant to cefoxitin (MIC 128 microg ml(-1)) and moxalactam (MIC 64 microg ml(-1)) and had elevated MIC of meropenem (2 microg ml(-1)) when compared to porin-expressing isolates (2-8, 4 and <0.06-0.125 microg ml(-1), respectively). Higher MICs, associated with loss of porins in outer membrane, were also observed for cefotaxime (4-8-fold), cefepime (>2-16-fold), ciprofloxacin (4-16-fold), imipenem and aztreonam (2-16-fold), but there was no significant difference among MICs of ceftazidime. The porin-deficient mutant was probably selected in vivo during ofloxacin therapy.
Skopková-Zarnayová
Martina
M
Department of Microbiology and Virology, Comenius University, Mlynska dolina B-2, 845 15 Bratislava, Slovakia. martina.skopkova@savba.sk
Siebor
Eliane
E
Rovná
Daniela
D
Bujdáková
Helena
H
Neuwirth
Catherine
C
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D002440:Cefoxitin / Q000494:pharmacology*; D018550:Cephalosporin Resistance; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005838:Genotype; D006801:Humans; D007525:Isoelectric Focusing; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008297:Male; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D002440:Cefoxitin; D001618:beta-Lactamases