The detection of drug resistance genes of carbapenem-resistant Klebsiella pneumonia and its homology analysis

ObjectiveTo explore the drug resistance genes of carbapenem-resistant Klebsiella pneumonia(CRKP), and its homology analysis.

MethodsForty strains of Klebsiella pneumonia were isolated from clinical samples from April to June 2018, and the drug sensitivity of which was identified using VITEK 2 COMPACT automatic bacterial sensitivity instrument.The carbapenem phenotypes of the 40 strains of Klebsiella pneumonia were screened using the modified hodge test(MHT) and modified carbapenem inactivation test(mCIM).PCR method was used to detect the main carbapenem resistance genes(including KPC, OXA-48 and NDM-1 genes).Matrix assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF MS) was used to analyze the homology of genes.

ResultsThe 40 strains of CRKP were isolated from ICU ward(55%), mainly from respiratory tract samples(80%), and the resistance rates of those to cephalosporins, aminoglycosides and macrolides were above 80%.Thirty-three strains were positive in MHT test and mCIM test, 2 strains were negative in MHT test and mCIM test, and the remaining 5 strains were positive in MHT test and negative in mCIM test.The KPC gene was detected in 32 strains, and the OXA-48 and NDM-1 genes were not detected.The results of homology analysis showed that 40 strains of CRKP were divided into 7 types, which included type A in 34 strains(85%), and type B, C, D, E, F and G in 1 strain, respectively(each accounting for 2.5%).

ConclusionsThe KPC-2 gene is the main genotype in CRKP, which can be divided into 7 kinds of types(type A as the main type).The study can provide the basis in effective treating and preventing the CRKP infection.