title: Effect of Resistance Mechanisms on the Inoculum Effect of Carbapenem in Klebsiella pneumoniae Isolates with Borderline Carbapenem Resistance.
abstract: We aimed to examine the effects of resistance mechanisms on several resistance phenotypes among carbapenem-resistant Klebsiella pneumoniae isolates with borderline carbapenem MICs. We compared carbapenemase-negative K. pneumoniae with carbapenemase-producing K. pneumoniae (CPKP) isolates with similar MICs. CPKP isolates exhibited a marked inoculum effect and were more resistant to the bactericidal effect of meropenem. This suggests that MIC measurements alone may not be sufficient in predicting the therapeutic efficacy of carbapenems against CPKP.
authors.affiliation: National Center for Infection Control, Ministry of Health, Tel Aviv, Israel; Section of Epidemiology, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel amosa@tlvmc.gov.il.
authors.forename: Amos
authors.initials: A
authors.lastname: Adler
authors.affiliation: National Center for Infection Control, Ministry of Health, Tel Aviv, Israel; Section of Epidemiology, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Ma'ayan
authors.initials: M
authors.lastname: Ben-Dalak
authors.affiliation: National Center for Infection Control, Ministry of Health, Tel Aviv, Israel; Section of Epidemiology, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Ina
authors.initials: I
authors.lastname: Chmelnitsky
authors.affiliation: National Center for Infection Control, Ministry of Health, Tel Aviv, Israel; Section of Epidemiology, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Carmeli
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015780:Carbapenems / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D001618:beta-Lactamases; C063912:carbapenemase