血标本碳青霉烯类耐药肺炎克雷伯菌的分子特征及危险因素分析

目的探讨血标本中碳青霉烯类耐药肺炎克雷伯菌(carbapenem-resistant Klebsiella pneumoniae, CRKP)的分子特征及相关危险因素,为临床诊治、预防此类菌株感染及明确菌株耐药机制提供实验室资料。方法收集2016年1月-2018年12月某医院血标本中鉴定为肺炎克雷伯菌的菌株共903株,收集患者临床资料。采用聚合酶链式反应及测序技术检测CRKP菌株携带的碳青霉烯酶基因,多位点序列分型分析携带bla_KPC-2的CRKP菌株的同源性。采用单因素及多因素logistic回归分析探讨血标本中分离出CRKP菌株的危险因素。结果 CRKP菌株检出率为46.84%,重症监护病房(intensive care unit,ICU)为主要来源。CRKP菌株对三代头孢及加酶抑制剂类耐药率大于90%,对氨基糖苷类耐药率超过60%。对替加环素及多粘菌素耐药分别为1.15%、1.22%。菌株携带主要携带bla_KPC-2耐药基因,ST11型为本地区流行型别。logistic回归分析揭示高血压(OR=4.375,95%CI:2.399～7.9...

Molecular characterization and risk factors analysis of carbapenem-resistant Klebsiella pneumoniae isolated from blood samples

Objective To explore the molecular characterization carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from blood samples and to investigate related risk factors, so as to provide laboratory basis for clinical diagnosis, treatment, prevention and clarification of the drug resistance mechanisms of this bacterial infection. Methods A total of 903 K. pneumoniae strains isolated from blood samples were collected from the First Affiliated Hospital of Zhengzhou University from January 2016 to December 2018. Drug susceptibility results and clinical data were collected. Polymerase chain reaction(PCR) and sequencing were used to detect carbapenemase genes in CRKP strains. Multilocus sequence typing(MLST) was performed to analyze the homology of K. pneumoniae carbapemase(KPC) producing strains. The risk factors of CRKP strains infection in blood samples were analyzed by univariate and multivariate logistic regression analysis. Results The rate of CRKP strains was 46.84%, intensive care unit(ICU) was the main source. Among CRKP strains, the resistance rate to third generation cephalosporins and enzyme inhibitors was more than 90%, and to aminoglycosides, the resistance rate was more than 60%. Strains resistant to tigecycline and polymyxin accounted for 1.15% and 1.22% respectively. BlaKPC-2 gene was the main carbapenem resistance gene carried by the strains. MLST analysis showed that ST11 was the prevalent type in this area. Multivariate logistic regression analysis revealed that hypertension(OR=4.375, 95%CI: 2.399～7.979), intensive care unit admission(OR=4.639, 95%CI: 1.839～11.707) and combined use of antibiotics(OR=3.548, 95%CI: 1.838～9.412) were independent risk factors for the detection of CRKP strains isolated from blood samples. Conclusions The detection rate of CRKP strains in this hospital is high. Clinical medical workers should strictly follow ICU occupancy instructions, control the occupancy rate of ICU and rationally use antimicrobialagents.