肠球菌耐药性及万古霉素耐药基因研究

目的:了解浙一医院2006年临床分离的肠球菌耐药性及万古霉素耐药基因型。方法:采用Kirby-Bauer(KB)法对临床分离的肠球菌进行药敏试验,结果按NCCLS/CLSI 2005年版标准判断及采用WH0NET 5.4软件进行统计分析;PCR法检测万古霉素耐药株耐药基因型。结果:2006年共分离肠球菌309株,屎肠球菌143株(46.3%),粪肠球菌133株(43.0%),鸟肠球菌21株(6.8%),铅黄肠球菌12株(3.9%),主要分离自引流液(胸腹水、胆汁)42.7%,尿液24.6%,血液15.5%;肠球菌对环丙沙星、利福平、红霉素敏感性<20%,粪肠球菌对氨苄西林、呋喃妥因、青霉素敏感率分别为90.9%、92.4%、72.2%,对高浓度庆大霉素的敏感率仅为39.2%;屎肠球菌对氨苄西林、青霉素、高浓度庆大霉素、呋喃妥因耐药率均超过70%,但对氯霉素、四环素敏感率分别为85.9%、78.9%,两者对磷霉素的敏感率比较接近(84.5%,82.4%)。VRE检出率为2.9%,屎肠球菌占90%,为VanA型耐药,粪肠球菌中未检测到万古霉素耐药株。结论:肠球菌耐药性较为严重,特别是首次在浙一医院分离到VanA型VRE,应引起临床和实验室高度重视。

Surveillance of antimicrobial resistance and vancomycin resistance genes in Enterococcus species

Objective:To investigate the antimicrobial resistance and vancomycin resistance genes in Enterococcus species isolated from Zhejiang First Hospital in 2006.Methods:Antimicrobial susceptibility testing was carried out by means of Kirby-bauer(KB),and the data were analyzed by Whonet 5.4 software.Vancomycin resistance genes were detected by PCR.Results:A total of 309 Enterococcus species(143 Enterococcus faecium,133 E.faecalis,21 E.avium and 12 E.casseliflavus) were isolated from Zhejiang First Hospital during 2006.The most common source of specimen were drainage fluids(including bile,peritoneal fluid,pleural fluid),urine and blood.The sensitive rates of enterococcal isolates to rifampicin,erythromycin,ciprofloxacin were lower than 20%.E.faecalis strains were susceptible to ampicillin(90.9%),nitrofurantoin(92.4%)and penicillin(72.2%),and only 39% of isolates were susceptible to gentamicin(high level).More than 70% of E.faecium isolates were resistant to ampicillin,nitrofurantoin,penicillin and gentamicin(high level),but the sensitive rates to Chloramphenicol,Tetracycline were 85.9% and 78.9%,respectively.Both E.faecalis isolates and E.faecium strains showed similar susceptibility to fosfomycin(84.5%,82.4%).The rate of vancomycin-resistant Enterococcus(VRE) was 2.9%,and most were E.faecium(90%).Vancomycin resistance genes vanA were detected in E.faecium strains.Vancomycin resistance strains in E.faecalis were not found.Conclusion:Enterococcus isolates exhibit multidrug resistance,VRE(VanA) are emerging in Zhejiang First Hospital at the first time and should be noted.