Evaluation of different methods for the detection of KPC b-lactamase in Klebsiella pneumoniae and escherichia coli

ABSTRACT

The worldwide increase in the occurrence and dissemination of Klebsiella pneumoniae carbapenemase [KPC] among Gram-negative pathogens makes critical the early detection of these enzymes. The aim of this study is the evaluation of the most appropriate method for the detection and identification of KPC producing Klebsiella pneumonia and Escherichia coli. Modified Hodge test [MHT], Boronic acid lest [BAT] and polymerase chain reaction [PCR] were evaluated for the detection of KPC-possessing isolates. A total of 60 urine samples and 60 sputum samples were collected from 79 patients in Chest Intensive Care Unit and Trauma intensive Care Unit in Assiut University Hospital. Sixty four isolates [26 Klebsiella pneumonia and 38 E. coil] were identified by conventional methods. The antibiotic susceptibility testing of isolates showed that 19% were resistant to meropenem, 17% were resistant to imipenem and 95% were resistant to ertapenem. Thirty seven isolates were MHT positive while twenty three only of them were Boronic acid and PCR positive. The results indicate that the MHT lack sensitivity while Boronic acid test is an excellent inhibitor of KPCs. PCR is the standard method for the detection of the KPCs but it's highly expensive