肺炎克雷伯菌临床分离株的耐药性与分子流行病学分析

目的了解我院住院患者临床肺炎克雷伯菌分离株的耐药性与分子流行特征,为临床抗感染及合理用药提供依据。方法收集2018年4-12月我院住院病人肺炎克雷伯菌临床分离株,采用纸片扩散法或自动化仪器法按统一方案进行抗菌药物敏感性试验;聚合酶链反应(PCR)法检测耐药基因;脉冲场凝胶电泳(PFGE)和多位点序列分型(MLST)技术对菌株进行同源性分析和分型。结果共分离到肺炎克雷伯菌211株,对第3代头孢(头孢噻肟)和第四代头孢(头孢吡肟)的耐药率分别为54.5%和44.1%,对碳青霉烯类抗菌药物亚胺培南和美罗培南的耐药率为32.7%和34.1%;其中107株(107/211,50.6%)菌株分离自ICU病房,56株(56/107,52.3%)为碳青霉烯类耐药肺炎克雷伯菌(CR-KP),MLST分型显示以ST11为主,PFGE分型结果主要为A型和F型两大聚类。结论肺炎克雷伯菌耐药率高,特别是分离自ICU病房的菌株耐药情况尤为严重,且携带KPC-2基因的ST11克隆株在ICU病房流行传播。

Analysis of antimicrobial resistance and molecular epidemiology of Klebsiella pneumoniae

Objective To analyze the antibiotic resistance and molecular epidemiology of Klebsiella pneumoniae in our hospital in order to provide evidence for clinical anti-infection and rational medication.Methods Klebsiella pneumoniae strains were isolated from inpatients treated in our hospital from April to December in 2018.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Polymerase chain reaction(PCR)assays were performed to detect drug resistance genes.Pulsed-field gel electrophoresis(PFGE)and multilocus sequence typing(MLST)were used for homologous analysis and typing.Results A total of 211 strains of K.pneumoniae were isolated.The resistance rates to the third-generation cefotaxime and the fourth-generation cefotaxime were 54.5%and 44.1%,respectively,and those to carbapenems(imipenem and meropenem)were 32.7%and 34.1%,respectively.Totally 107 strains(107/211,50.6%)were isolated from ICU wards,of which 56 strains(56/107,52.3%)were carbapenem-resistant Klebsiella pneumoniae(CR-KP).The K.pneumoniae isolates belonged to 5 different sequence types(ST),with ST11 being the most common.The results of PFGE typing showled there were mainly two types of clustering:A and F.Conclusion The drug resistance rate of Klebsiella pneumoniae strains is high,especially those isolated from the ICU wards.Furthermore,the KPC-2-producing Klebsiella pneumoniae ST11 is popular in ICU wards.