碳青霉烯耐药肺炎克雷伯菌引起新生儿感染的耐药机制研究  

Antimicrobial resistant mechanisms of carbapenem-resistant Klebsiella pneumonia infection in newborns

作　　者：金炎[1] 王勇[1] 邵春红[1] 张炳昌[1] 李平[1] 范会[1] 

机构地区：[1]山东大学附属省立医院检验科,济南250021

出　　处：《中华检验医学杂志》2015年第11期751-755,共5页Chinese Journal of Laboratory Medicine

摘　　要：目的研究新生儿感染碳青霉烯类药物耐药肺炎克雷伯菌（CR—KP）的耐药机制及耐药基因的传播方式。方法采用回顾性调查方法收集山东省立医院2011年4月至2013年10月儿科患者分离的非重复CR—KP；PCR扩增耐药基因并测序；脉冲场凝胶电泳（PFGE）分析耐药菌携带质粒；接合转化试验证明携带耐药基因质粒的可移动性，多位点序列分型（MLST）方法对菌株进行同源性分析；采用PCR和SDS—PAGE方法对菌株的外膜孔道蛋白进行分析。结果共检m37株CR—KP，对亚胺培南、美岁培南、厄他培南的耐药率分别为89．2％（33／37）、83．8％（31／37）、97．3％（36／37），对替加环素、左氧氟沙星、阿米卡星、黏菌素敏感率为100％（37／37），对其他大多数药物耐药。PCR检m携带blaNDM-1、blalMP-4和blalMP-8的菌株分别为67．6％（25／37）、35．1％（13／37）和2．7％（1／37），其中同时携带blaNDM-1和blalMP-4的菌株2株。PFGE显示所有菌株携带2—4个质粒，接合试验证实blaNDM-1和blalMP-4可以通过质粒传播。MLST分型发现37株CR—KP分别属于ST20、ST17、ST54、ST705、ST290型，提示新生儿患者中出现分别由携带blaNDM-1和blalMP-4肺炎克雷伯菌引起医院感染的暴发。SDS—PAGE提示所有菌株无外膜蛋白缺失。结论本院新生儿患者分离的肺炎克雷伯菌对碳青酶烯类药物耐药的主要机制是产生了blaNDM-1或blalMP4型碳青酶烯酶，并且发现了同时携带2种碳青霉烯酶的肺炎克雷伯菌。Objective To investigate the antimierobial resistant and transmission mechanisms of earbapenem-resistant K. pneumonia （CR-KP） infection of newborns. Methods A retrospective study was conducted on totally 37 non-repetitive CR-KP which were isolated from patients hospitalized between April 2011 and October 2013. Resistance genes were identified by PCR and sequencing. Plasmid was analyzed by pulsed-field gel electrophoresis （PFCE）. Conjugation experiments were performed to determine the transferability of beta-lactamase. Multilocus sequence typing （MLST） was used to determine the genotypes and homology of these isolates. Out-membrane proteins were examined by PCR and sodium dodecyl sulfate polyaclylamide gel electrophoresis （SDS-PAGE）. Results Thirty-seven CR-KP isolates were tested. The resistant rates of imipenem, meropenem, ertapenem were 89.2% （ 33/37 ） , 83.8% （ 31/37 ） ,97.3% （ 36/ 37）, respectively. All the 37 CR-KP exhibited 100% （37/37） sensitivity to tigecycline, colistin, levofloxacin and amikacin, while resistance to most of the other antibiotics. By PCR, 67.6% （25/37） isolates were blaNDM-1 positive, 35. 1% （ 13/37 ） isolates were blaIMP-4 positive and 2. 7% （1/37） isolate were blaIMP-8 positive, including two isolates calxying both blaNDM-1 and blalMP-4. PFGE results showed that the isolates calTied 2 -4 plasmids and both blaNDM-1 and blaIMP-4 were transferable by plasmids. M LST assigned them to sequence type （ST） 20, ST17, ST54, ST705, ST290,which showed that there were infectious outbreaks caused by NDM-1-producing and IMP-4-producing respectively among newborns. SDS- PAGE result indicated that there was no absence of outer nlembrane proteins OmpK35 and OmpK36. Conclusions The main resistant mechanisms of CR-KP causing infection in newborns were those the isolates carried carbapenemase of blaNDM-I or blaIMP-4 and the K. pneumonia with two kinds ofearbapemenase were detected.

关 键 词：克雷伯菌感染 肺炎克雷伯菌 抗药性 细菌 卡巴配能类 Β内酰胺酶类 

分 类 号：R722.13[医药卫生—儿科] R446.5[医药卫生—临床医学]