2010年中国CHINET血流感染的病原菌分布及耐药性

Bacterial distribution and susceptibility in bloodstream infections in China antibiotic resistance surveillance program CHINET 2010

目的了解2010年CHINET血培养分离菌的菌种分布和耐药性。方法对CHINET细菌耐药监测网2010年1月至2010年12月所有血标本按常规方法进行细菌分离、培养、鉴定。按统一方案用K-B纸片扩散法进行抗菌药敏感试验。结果 2010年自血液标本中共获分离细菌5 646株,其中革兰阳性球菌占64.3%,革兰阴性杆菌占35.6%。最常见的分离菌分别为凝固酶阴性葡萄球菌(47.0%)、大肠埃希菌(1 5.0%)、肠球菌属细菌(7.4%)、克雷伯菌属细菌(6.0%)、金葡菌(5.6%)、不动杆菌属细菌(3.9%)、假单胞菌属细菌(2.9%)、草绿色链球菌(2.9%)、肠杆菌属细菌(1.9%)、沙门菌属细菌(1.2%)和嗜麦芽窄食单胞菌(1.1%),占分离菌株的94.8%。MRSA及MRCNS分别占金葡菌和凝固酶阴性葡萄球菌的51.1%和56.8%。粪肠球菌对高浓度庆大霉素和氨苄西林的耐药率分别为34.3%和14.7%,屎肠球菌对多数测试药物的耐药率显著高于粪肠球菌。草绿色链球菌对青霉素的耐药率为11.2%。葡萄球菌、肺炎链球菌和其他链球菌属细菌中均未发现万古霉素、替考拉宁和利奈唑胺耐药菌株,粪肠球菌和屎肠球菌对万古霉素的耐药率分别为2.1%和7.0%。大肠埃希菌、克雷伯菌属、肠杆菌属、沙雷菌属、变形菌属和枸橼酸菌属细菌等肠杆菌科细菌对亚胺培南、美罗培南的耐药率在0～10%,但克雷伯菌属、肠杆菌属、沙雷菌属和变形菌属细菌对厄他培南的耐药率达10%～20%。不发酵糖革兰阴性杆菌对碳青霉烯类抗生素耐药率较高,铜绿假单胞菌对碳青霉烯类抗生素的耐药率为18.3%～22%,但不动杆菌属细菌耐药率达57%。结论 2010年CHINET监测资料显示革兰阳性菌,尤其是CNS在血流感染中占重要地位,血培养分离株对常用抗菌药严重耐药,因此应合理应用抗菌药物,并加强医院感染控制措施以抑制耐药菌传播。

blood culture were routinely identified. The antimicrobial susceptibility to more than 20 antimicrobial agents was determined by Kirby-Bauer method in the participating institutions. Results A total of 5 646 strains were isolated from blood specimens in 2010. Gram positive cocci and Gram negative bacilli accounted for 64.3% and 35.60%, respectively. The most frequent isolates were coagulase-negative Staphylococcus （CNS） （47%）, E. coli （15.1%）, Enterococcus （7.4%）, Klebsiella （6.0%）, S. au- reus （5.6%）, Acinetobacter （3. 9%）, P. aeruginosa （2. 9%）, S. viridans （2. 9%）, Enterobacter （ 1. 9%）, Salmonella （1.2%） and S. maltophilia （1. 1%）, taken together accounting for 94.8% of all blood culture isolates. The prevalence of MRSA in S. aureus and MRCNS in coagulase-negative Staphylococcus was 51.1% and 56.8%, respectively. The percentage of gentamicin- or ampicillin-resistant E. faecium was 34.3% and 14.7%, respectively, significantly higher than that of E. faecalis. No strain was found resistant to vancomycin, teicoplanin or linezolid in Staphylococcus, Streptococcus or S. pneu- moniae. The prevalence of vancomycin-resistant strain was 2.1% in E. faecalis and 7.0% in E. faecium. Imipenem or mero- penem resistance was found in about 0-10% of the isolates in the Enterobacteriaceae species, including E. coli, Klebsiella, En- terobacter, Serratia, and Citrobacter. About 10% to 20% of the isolates were resistant to ertapenem in Klebsiella, Enter- obacter, Serratia, and Proteus species. Nonfermenters were highly resistant to carbapenems, especially Acinetobacter （57% resistant）. Carbapenem resistance was found in 18.3% to 22% of P. aeruginosa isolates. Conclusions Gram positive coccus plays an important role in blood stream infections, especially CNS. The resistance to the first line antibiotics is common among all blood isolates. Antimicrobial agents should be used appropriately to reduce the selection pressure. Hospital infection control measures should be strengthened to prevent the spread of resistant organisms.