[Comparative activity of ertapenem against extended-spectrum beta-lactamase-producing or plasmid-mediated AmpC beta-lactamase-producing Klebsiella pneumoniae].
BACKGROUND
The effect of porin loss and inoculum size on the comparative activity of ertapenem against either extended-spectrum beta lactamase-producing (ESBL) or plasmid-mediated AmpC beta lactamase-producing (pACBL) Klebsiella pneumoniae strains was evaluated.


METHODS
Microdilution using 2 different bacterial inocula.


RESULTS
Imipenem, amikacin, ertapenem, and cefepime were the most active agents under standard conditions. Ertapenem was more highly affected by porin loss than imipenem.


CONCLUSIONS
Ertapenem showed high activity against K. pneumoniae strains expressing ESBL, pACBL or both. Strains deficient in porins showed decreased susceptibility to beta lactams. The inoculum effect had a greater impact on imipenem than on ertapenem.
Hernández
José Ramón
JR
Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, España. joserhb@us.es
Conejo
María del Carmen
Mdel C
Pascual
Alvaro
A
D000583:Amikacin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D000077723:Cefepime; D002511:Cephalosporins / Q000494:pharmacology; D000077727:Ertapenem; D015378:Imipenem / Q000494:pharmacology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D008826:Microbial Sensitivity Tests; D018272:Porins / Q000172:deficiency; D011815:R Factors / Q000235:genetics; D013379:Substrate Specificity; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000032:analysis* / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002511:Cephalosporins; C119261:OmpK35 porin, Klebsiella pneumoniae; C092233:OmpK36 protein, Klebsiella pneumoniae; D018272:Porins; D047090:beta-Lactams; D015378:Imipenem; D000077723:Cefepime; D000583:Amikacin; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; D000077727:Ertapenem