CAJ | 학술논문

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201 1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.结果共检出37株CR-KP,对亚胺培南、美罗培南、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检出携带blaNDM-1、blaIMP-4和blaIMP-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blaIMP-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blaIMP--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blaIMP-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blaIMP-4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.
목적 연구신생인감염탄청매희류약물내약폐염극뢰백균(CR-KP)적내약궤제급내약기인적전파방식.방법 채용회고성조사방법수집산동성립의원201 1년4월지2013년10월인과환자분리적비중복CR-KP;PCR확증내약기인병측서;맥충장응효전영(PFGE)분석내약균휴대질립;접합전화시험증명휴대내약기인질립적가이동성,다위점서렬분형(MLST)방법대균주진행동원성분석;채용PCR화SDS-PAGE방법대균주적외막공도단백진행분석.결과 공검출37주CR-KP,대아알배남、미라배남、액타배남적내약솔분별위89.2％(33/37)、83.8％(31/37)、97.3％(36/37),대체가배소、좌양불사성、아미잡성、점균소민감솔위100％(37/37),대기타대다수약물내약.PCR검출휴대blaNDM-1、blaIMP-4화blaIMP-8적균주분별위67.6％(25/37)、35.1％ (13/37)화2.7％(1/37),기중동시휴대blaNDM-1화blaIMP-4적균주2주.PFGE현시소유균주휴대2～4개질립,접합시험증실blaNDM-1화blaIMP--4가이통과질립전파.MLST분형발현37주CR-KP분별속우ST20、ST17、ST54、ST705、ST290형,제시신생인환자중출현분별유휴대blaNDM-1화blaIMP-4폐염극뢰백균인기의원감염적폭발.SDS-PAGE제시소유균주무외막단백결실.결론 본원신생인환자분리적폐염극뢰백균대탄청매희류약물내약적주요궤제시산생료blaNDM-1혹blaIMP-4형탄청매희매,병차발현료동시휴대2충탄청매희매적폐염극뢰백균.
Objective To investigate the antimicrobial resistant and transmission mechanisms of carbapenem-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 (PFGE).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 polyacrylamide 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 carrying both blaNDM-1 and blaIMP-4.PFGE results showed that the isolates carried 2-4 plasmids and both blaNDM-1 and blaIMP-4 were transferable by plasmids.MLST 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 membrane proteins OmpK35 and OmpK36.Conclusions The main resistant mechanisms of CR-KP causing infection in newborns were those the isolates carried carbapenemase of blaNDM-1 or blaIMP-4 and the K.pneumonia with two kinds of carbapemenase were detected.