下呼吸道分离肺炎克雷伯菌CRISPR-Cas系统分布及其与细菌毒力的相关性  

Distribution of CRISPR-Cas system in Klebsiella pneumoniae strains isolated from lower respiratory tract and its association with bacterial virulence

作　　者：王君君 吕承秀 李庆 WANG Jun-jun;LYU Cheng-xiu;LI Qing(Zibo First Hospital,Zibo,Shandong 255200,China)

机构地区：[1]淄博市第一医院检验科,山东淄博255200

出　　处：《中华医院感染学杂志》2023年第6期821-825,共5页Chinese Journal of Nosocomiology

基　　金：山东省医药卫生科技发展计划基金资助项目(2018WS008)。

摘　　要：目的 了解下呼吸道分离肺炎克雷伯菌规则间隔的短回文重复序列及相关蛋白(CRISPR-Cas)系统分布及其与细菌毒力的相关性。方法 收集2019年8月-2021年12月淄博市第一医院下呼吸道标本分离的200株非重复肺炎克雷伯菌进行毒力基因、CRISPR-Cas系统基因检测,分析下呼吸道分离肺炎克雷伯菌中CRISPR-Cas系统的亚型分布、CRISPR-Cas系统亚型与细菌毒力基因的相关性。结果 200株下呼吸道分离的肺炎克雷伯菌中除毒力基因prmpA2外,毒力基因iucA、iroB、prmpA、peg-344的阳性率均在50%以上;200株菌中携带CRISPR-Cas系统I-E*型菌株50株,占比25.00%,携带CRISPR-Cas系统I-E型菌株21株,占比10.50%;质谱图谱聚类分析发现,CRISPR-Cas系统I-E*型肺炎克雷伯菌具有同源性,CRISPR-Cas系统I-E型菌株中未发现聚类现象;毒力基因在携带CRISPR-Cas系统I-E*型菌株中的阳性率高于CRISPR-Cas系统基因阴性菌株(P<0.05),毒力基因在CRISPR-Cas系统I-E型阳性菌株及CRISPR-Cas系统基因阴性菌株中的阳性率比较,无统计学差异。结论 下呼吸道临床分离肺炎克雷伯菌中CRISPR-Cas系统以I-E*型为主,携带CRISPR-Cas系统I-E*型阳性菌株毒力基因阳性率高于CRISPR-Cas系统基因阴性菌株。OBJECTIVE To understand the distribution of clustered regularly interspaced short palindromic repeats associated with a Cas endonuclease(CRISPR-Cas) system in Klebsiella pneumoniae strains isolated from lower respiratory tract and analyze its association with bacterial virulence. METHODS Totally 200 non-repetitive K.pneumoniae strains were isolated from lower respiratory tract specimens in Zibo First Hospital from Aug 2019 to Dec 2021, the virulence genes and CRISPR-Cas system genes were detected. The subtypes of CRISPR-Cas system in the K.pneumoniae strains were analyzed, and the association of the subtypes of CRISPR-Cas system with the bacterial virulence genes was observed. RESULTS The positive rates of virulence genes iucA, iroB, prmpA and peg-344 were more than 50% among the 200 strains of K.pneumoniae isolated from lower respiratory tract. Among the 200 strains, 50(25.00%) carried with CRISPR-Cas system I-E* type, 21(10.50%) carried with CRISPR-Cas system I-E type. The cluster analysis of mass spectrum showed that the K.pneumoniae with CRISPR-Cas system type I-E * had homology, but no homology of K.pneumoniae with CRISPR-Cas system type I-E was found. The positive rates of virulence genes were higher in the strains carrying with CRISPR-Cas system type I-E * than in the strains negative for CRISPR-Cas system genes(P<0.05). There were no significant differences in the positive rates of virulence genes between the CRISPR-Cas system type I-E-positive strains and the CRISPR-Cas system gene-negative strains. CONCLUSION The strains carrying with CRISPR-Cas system type I-E* are dominant among the clinical K.pneumoniae isolates from lower respiratory tract, and the positive rates of virulence genes of the strains carrying with CRISPR-Cas system type I-E* are higher than those of the CRISPR-Cas system genes-negative strains.

关 键 词：下呼吸道 肺炎克雷伯菌 规则间隔的短回文重复序列及相关蛋白系统 毒力基因 等位基因 聚类分析 

分 类 号：R378.996[医药卫生—病原生物学]