耐碳青霉烯酶类肺炎克雷伯菌中整合子及相关基因盒的分布  

Distribution of integrons and inserted gene cassettes in carbapenem-resistant Klebsiella pneumoniae

作　　者：吴秀萍[1,2] 魏取好[1] 胡庆丰[1] 吕火祥[1] 周永列[1] 

机构地区：[1]浙江省人民医院检验中心,浙江杭州310014 [2]浙江中医药大学生命科学院,浙江杭州310053

出　　处：《中华医院感染学杂志》2012年第7期1329-1332,共4页Chinese Journal of Nosocomiology

基　　金：浙江省自然科学基金(Y2110743);浙江省医学重点学科建设基金(07-010)

摘　　要：目的了解耐碳青霉烯类肺炎克雷伯菌整合子及相关基因盒的分布,分析整合子与耐碳青霉烯类肺炎克雷伯菌多药耐药的关系。方法采用革兰阴性杆菌药敏卡检测耐碳青霉烯类肺炎克雷伯菌对抗菌药物的敏感性,聚合酶链反应(PCR)法检测Ⅰ、Ⅱ、Ⅲ类整合酶基因(intⅠ1、intⅡ2、intⅢ3)及Ⅰ类整合子可变区基因盒,并分析可变区上游启动子的类型。结果 74株耐碳青霉烯类肺炎克雷伯菌中有67株检测到Ⅰ类整合酶基因,检出率为90.5%,2株检测到Ⅱ类整合酶基因,检出率为2.7%,未检测到Ⅲ类整合酶基因阳性菌株;55株(74.3%)成功扩增出Ⅰ类整合子可变区,主要携带甲氧苄啶及早期使用的氨基糖苷类抗菌药物耐药基因,可变区启动子大多为弱启动子;携带Ⅰ类整合子菌株对常用抗菌药物的耐药率与Ⅰ类整合子阴性菌株之间的差异无统计学意义。结论Ⅰ类整合子及相关基因盒在耐碳青霉烯类肺炎克雷伯菌中分布广泛,所携带的整合子具有非常强的从周围环境中捕获耐药性基因盒的能力。OBJECTIVE To investigate the distribution of integrons and integrated gene cassettes in carbapenem resistant Klebsiella pneumoniae and analyze the relationship between integrons and multiple drug resistance. METHODS The antimicrobial susceptibility testing for carbapenemresistant Klebsiella pneurnoniae was performed with VITEK64 system. PCR method was used to detect variable regions of class I , Ⅱ , and Ill integron integrase genes（int I 1, int Ⅱ 2, and intⅢ 3）as well as the class I integrons of inserted gene cassettes in of, the types of the promoters in upstream of the variable region were analyzed. RESULTS Among 74 carbapenem resistant K. pneumoniae clinical isolates, int I 1 genes were detected in 67 isolates （90. 5%）, int I 2 were detected in 2 isolates（2. 7%）, no int I 3 genes were detected. Variable regions were detected in 55 isolates （74.3%）; high prevalence of gene cassettes were detected in those with trimethoprim and in early used aminoglycoside antibiotics. The predominant promoters of variable regions were weak promoters. There was no statistical significant difference in antibiotic resistance between int I 1 positive isolates and negative ones. CONCLUSION Class 1 integrons as well as their associated gene cassettes are prevalent among carbapenemresist ant K. pneurnoniae isolates. These integrons have strong capacity of capturing antibiotic resistance gene cassettes from their surroundings.

关 键 词：肺炎克雷伯菌 整合子 基因盒 启动子 

分 类 号：R378.996[医药卫生—病原生物学]