消化内科患者感染粪肠球菌的毒力基因检测及耐药性研究

Research on detection of virulence genes and drug resistance of Enterococcus faecalis in patients from department of gastroenterology

[目的]检测我院消化内科患者感染粪肠球菌的毒力基因,分析粪肠球菌的耐药性。[方法]收集患者的痰液、血液及尿液标本,分离并鉴定粪肠球菌(重复的除外)158株;制备细菌DNA模板并设计引物,PCR扩增粪肠球菌的毒力基因,采用K-B法测定粪肠球菌对一般常用抗生素的耐药性。[结果]患者感染的粪肠球菌分离株8种毒力基因为ace基因(335bp)、cylA基因(327bp)、cylB基因(843bp)、cylM基因(742bp)、cylL1基因(624bp)、efaA基因(180bp)、esp基因(933bp)及gelE基因(1200bp),片段大小与理论值相符;ace、cylA、cylB、cylM、cylL1、efaA、esp及gelE基因的阳性检出率分别为15.19%、55.70%、44.94%、48.10%、53.16%、69.62%、56.96%及63.92%;粪肠球菌临床分离株对四环素、红霉素、庆大霉素、氨苄西林、环丙沙星、呋喃妥因及万古霉素的耐药率分别为77.85%、81.65%、74.05%、41.14%、53.16%、17.72%及6.96%,对替考拉宁未产生耐药性。[结论]推测本院消化内科患者感染粪肠球菌8种毒力基因的携带率为15.19%~69.62%,粪肠球菌对四环素等常用抗生素均有不同程度的耐药性,对替考拉宁无耐药性,可为临床治疗提供一定参考。

[Objective]To determine the virulence genes in Enterococcus faecalis in infecting patients from department of gastroenterology of our hospital, and to analyze the drug resistance of Enterococcus faecalis. [Methods]Sputum, blood and urine samples were collected from patients, Enterococcus faecalis were isolated and identified（remove duplicate）. The virulence genes of Enterococcus faecalis were amplified by a process including template preparation, primer design, PCR amplification with thermal cycling. The drug resistance of Enterococcus faecalis was analyzed by K-B method. [Results]Eight virulence genes were detected from infected patients in department of gastroenterology of our hospital, amplification indicated that the ace gene was 335 bp in size,the cylA gene was 327 bp in size,the cylB gene was 843 bp in size,the cylM gene was 742 bp in size,the cylL1 gene was 624 bp in size,and the efaA gene was 180 bp in size,the esp gene was 933 bp in size,and the gelE gene was 1 200 bp in size. The positive detection rate of ace＇cylA, cylB,cylM,cylLl,efaA,esp and gelE gene were 15.19%,55.70%,44.94%,48.10%/00,53.16~/00,69.62%, 56.96% and 63.92%, respectively. Enterococcus faecalis resistant to tetracycline, erythromycin, gentami- cin, ampicillin, ciprofloxacin and nitrofurantoin and vancomycin were 77.85 %, 81.65 %, 74.05 %, 41.14 %, 53.16 %, 17.72 ~ and 6.96%, respectively. Enterococcus faecalis was not resistant to teicoplanin. [Conclu- sion]The results showed that the genes carrying rate of patients infected with Enterococcus faecalis from department of gastroenterology was 15.19%--69.62%,Enterococcus faecalis have different levels of re- sistance to antibiotics（such as tetracycline）, but Enterococcus faecalis is not resistant to teicoplanin. The analysis of drug resistance can guide the rational use of drugs in clinical practice.