Detection of the Klebsiella pneumoniae carbapenemase (KPC) in K.pneumoniae Isolated from the Clinical Samples by the Phenotypic and Genotypic Methods

Background and Objective: The production of carbapenemases especially Klebsiella pneumoniae carbapenemase (KPC) is the most important mechanism of enzymatic resistance in isolated Enterobacteriaceae such as K. pneumoniae. The purpose of this study was detected of the carbapenemase producer K.pneumoniae strains with phenotypic and genotypicmethods. Method: Out of 800 strains, 270 K. pneumoniae strains (33.7%), were obtained. Antibiotic susceptibility test was performed by disk diffusion method in accordance with CLSI guidelines. Carbapenem resistant strains were identified by the Modified Hodge Test based on CLSI instruction and PCR for surveying the presence of bla-KPC gene.Results:A total 270 K. pneumoniae strains were collected. Antibiotic susceptibility test results showedthe highest and lowest resistance was related to piperacillin (60.6%) and carbapenems (14.6%) respectively.80.5%(33 of 41) isolates were positive by MHT, but all of them (100%)were negative for amplification of the bla-KPC gene in the PCR method. Conclusion:The MHT was an appropriate method for approving carbapenemase production. Moreover, a laboratory could accept the carbapenemase production with PCR method for the bla- KPCgene, which has the additional profit of validating which KPC is present.

Keywords:

Klebsiella pneumoniae , Carbapenem Resistance , bla-KPC gene , MHT