Evaluation of a Real-Time PCR Assay for the Detection of the Klebsiella pneumoniae Carbapenemase Genes in Microbiological Samples in Comparison With the Modified

Transfer of the blaKPC genes encoding the Klebsiella pneumoniae carbapenemase (KPC) are increasingly responsible for emerging carbapenem resistance. The modified Hodge test (MHT) is recommended for the detection of KPC. We compared MHT with a real-time polymerase chain reaction (PCR) assay targeting common subtypes of blaKPC, using previously described forward and reverse primer sequences. The PCR product was detected using SYBR Green (Applied Biosystems, Foster City, CA) and confirmed by melt curve analysis. PCR was positive in 96 % (52/54) of isolates that were MHT+, 90 % (28/31) of MHT – isolates were PCR–, and the results were strongly correlated (P =.0001; Fisher exact test). The PCR assay is a sensitive, specific, and rapid test for detecting blaKPC genes. It could help optimize patient care by reducing the time taken to institute appropriate antimicrobial therapy and so help improve patient outcomes. Carbapenems are highly efficacious drugs for treating infections with extended-spectrum β-lactamase–producing gram-negative bacteria.1 Previously, resistance to carbapenems has been rare; however, the emergence of transmissible carba-penem resistance is now a growing concern.1-9 An increasingly common mechanism of carbapenem resistance is the class-A, Klebsiella pneumoniae carbapenemase (KPC).2,8,10-13 KPCs have been reported in K pneumoniae and in Klebsiella oxytoca