1999-2006年北京朝阳医院革兰阳性球菌耐药性分析

Continuous surveillance of antimicrobial resistance among gram-positive coccus from 1999 to 2006 at Beijing Chaoyang Hospital

目的探讨北京朝阳医院1999-2006年临床分离的革兰阳性球菌的耐药变迁，以指导临床合理使用抗菌药物。方法采用MIC法进行抗菌药物敏感性试验，以WHONET5．3软件分析数据。结果6192株临床分离的革兰阳性球菌中，前4位病原菌依次为凝固酶阴性葡萄球菌、金黄葡萄球菌、粪肠球菌、屎肠球菌。耐甲氧西林金黄葡萄球菌（MRSA）、耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）平均检出率分别为88．4％、86．9％，金黄葡萄球菌对青霉素、氨苄西林耐药率最高，8年间始终保持在90．0％以上。未发现对万古霉素耐药或中介的金黄葡萄球菌或凝固酶阴性葡萄球菌。2003年首次分离耐万古霉素肠球菌（VRE），至2006年共发现30株VRE，其中13株为耐万古霉素粪肠球菌，均为VanB基因型；17株为耐万古霉素屎肠球菌，均为VanA基因型，耐万古霉素屎肠球菌分离率呈上升趋势。对于粪肠球菌活性最高的是万古霉素、氨苄西林、青霉素，敏感率分别为98．7％、95．7％、85．6％。但是青霉素敏感性略有下降，从94．3％降至84．6％。克林霉素的耐药率8年中始终维持在99．0％以上。屎肠球菌对红霉素、克林霉素的耐药率均达95．0％以上，对青霉素、氨苄西林、环丙沙星的耐药率均大于90．0％。屎肠球菌最为敏感的药物是万古霉素，对四环素敏感性出现上升的趋势，从27．8％升到82．6％。结论万古霉素对临床常见的革兰阳性菌保持很高的活性，发现30株耐万古霉素的肠球菌。

Objective To investigate the change of antimicrobial resistance among gram-positive cocci from 1999 to 2006 in Beijing Chaoyang Hospital. Methods Antimicrobial susceptibility test was carried out by MIC method, data were analyzed by WHONET 5.3 software. Results A total of 6192 clinical isolates were collected. The top four pathogens were Staphylococcus coagulase-negative, Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium. The prevalence of methicillin-resistant S. aureus and coagulase-negative were identified in 88.4% and 86.9%, respectively. The resistance rates of S. aureus to penicillin G and ampicillin were more than 90.0% during 1999-2006. Neither strains of S. aureus nor strains of coagulase-negative Staphylococcus were found resistant to vancomycin. Vancomycin-resistant Enterococci （VRE） strains were firstly isolated in 2003, thirteen vaneomyein-resistant E.faecalis isolates were identified as VanB genotype by PCR and sequencing. The VanA gene was confirmed by PCR and sequencing in seventeen vancomycin-resistant E. faecium, vancomycin-resistance E. faecium rate increased sharply. The most active antibiotics against E. faecalis were vancomycin, ampicillin, penicillin with the susceptible rates of 98.7% , 95.7% and 85.6% , however, the susceptibility rate of E. faecalis to penicillin decreased from 94.3% -84.6%. The resistance rates of E.faecalis to clindamycin was 99.0%. The resistance rates of E. faecium to erythromycin and clindamycin were more than 95.0%. The resistance rates of E.faecium to ampicillin, penicillin, ciprofloxacin were more than 90.0%. The most active antibiotics against E. faecium was vancomycin. The susceptibility rate of E.faecium to tetracycline increased from 27.8% to 82.6%. Conclusion Vancomycin remains highly active against gram-positive cocci. A total of 30 Enterococci isolates were found resistant to vancomycin.