关键词: 肺炎克雷伯菌, 类肺炎克雷伯菌, 变栖克雷伯菌, 分子分群, 毒力基因, 耐药基因

Abstract:

Objective To analyze the classification and epidemiology characteristics（capsular serotype，drug resistance gene and virulence gene） of Klebsiella pneumoniae isolated from clinic，and to provide a reference for diagnosis and treatment. Methods Non-repetitive 143 isolates of Klebsiella pneumoniae were collected from Linfen Central Hospital from January 2021 to January 2022. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used for isolate identification，and the drug resistance was determined by VITEK-2 system and K-B disk diffusion. Molecular classification and capsular serotype were performed by polymerase chain reaction（PCR） and gene sequencing. Virulence genes and drug resistance genes were determined by polymerase chain reaction（PCR）. Results A total of 4 isolates of Klebsiella variicola（KpⅢ），4 isolates of Klebsiella quasipneumoniae（KpⅡ） and 135 isolates of Klebsiella pneumoniae（KpⅠ） were identified. The main capsular serotypes of KpⅠ were K1，K2 and K57. K1 was the main capsular serotype of KpⅡ. The capsular serotypes of KpⅢ dispersed distribution. KpⅢ and KpⅡonly carried with SHV，OKP and LEN genes，while KpⅠcarried multiple drug resistance genes. The drug resistance of KpⅠwas higher than others. Virulence genes were determined in all the isolates. The rate of virulence genes for fimH，mrkD and ENT was >95% in the 3 isolate groups. The carrying rates of KFU in KpⅡ and KpⅢ（100.00%） were higher than that in KpⅠ（73.33%），and the carrying rate of YBT in KpⅠ，KpⅡ and KpⅢ were 54.81%，25.00% and 0%，respectively. Conclusions The clinical isolates of Klebsiella pneumoniae are mainly KpⅠ. There were differences in carrying rate of virulence gene，drug resistance gene and capsular serotype distribution.

Key words: Klebsiella pneumoniae, Klebsiella quasipneumoniae, Klebsiella variicola, Molecular classification, Virulence gene, Drug resistance gene