全自动微生物鉴定药敏分析仪对临床相关细菌药敏测定能力的评估

Evaluation of Vitek 2 Compact for antimicrobial susceptibility testing of clinically relevant bacteria

目的评估 Vitek 2 Compact 全自动微生物鉴定药敏分析仪对临床相关革兰阴性菌和革兰阳性菌的药敏测定能力。方法选取89株北京协和医院临床菌株(革兰阴性菌48株,革兰阳性菌41株)和66株本实验室保存的参考菌株(革兰阴性菌41株,革兰阳性菌25株)为评估菌株,分别采用 Vitek 2 Compact AST-GN09(革兰阴性菌)、AST-P536(葡萄球菌)、AST-P534(肠球菌和无乳链球菌)和 AST-P533(肺炎链球菌)药敏卡进行药敏测定,测定结果与参考方法 Etest 结果进行对照。32株以 CLSI 纸片确证法检测为ESBL阳性的菌株(其中包括16株经PCR扩增测序确定产 SHV 或 CTX-M 型 ESBLs 的菌株),以 Vitek 2 Compact 检测其是否产 ESBLs。结果根据临床和实验室标准协会(CLSI)规定的药敏折点,对 Vitek 2 Compact 和 Etest 法测得的药敏结果进行解释,在全部的1626株细菌-抗生素组合中,Vitek 2 Compact 药敏测定的标准符合率(CA)为90.83%,严重错误(VME)为4.91%,重大错误(ME)为2.09%,一般错误(MIE)为6.40%。90%以上的肠杆菌科菌、非发酵糖菌、微球菌科菌和链球菌科菌分别在11、13、11和12 h 内完成测定。32株 ESBL 阳性菌以 Vitek 2Compact 检测均为阳性。结论 Vitek 2 Compact 能够对临床相关革兰阴性菌和革兰阳性菌的药物敏感性进行准确、快速的测定,对 ESBLs 检测的敏感性、特异性高,是临床微生物实验室的有利工具。

Objective To evaluate a new system, Vitek 2 Compact, for antimicrobial susceptibility testing （AST） of gram-negative and gram-positive bacteria. Methods Eighty-nine clinical isolates of Peking Union Medical College Hospital, including 48 gram-negative strains and 41 gram-positive strains, and 66 reference strains kept in our laboratory, including 41 gram-negative strains and 25 gram-positive strains, were studied. The antimicrobial susceptibility of these strains were tested by Vitek 2 Compact with AST- GN09 （for gram-negative bacteria）, AST-P536 （for Staphylococci ）, AST-P534 （for Enterococci and S. agalactiae）, and AST-P533 （for S. pneumoniae） susceptibility cards. The Etest was used as the reference method for comparision. Thirty-two ESBL-producing strains assessed with the confirmatory tests for ESBLs of CLSI （ 16 strains of them had been confirmed by PCR amplified and sequencing） were detected for ESBLs by Vitek 2 Compact. Results According to the breakpoints of Clinical and Laboratory Standards Institute （ CLSI）, for the 1 626 microorganism-antibiotic combinations, Vitek 2 Compact gave 90. 83% strains with category agreement （CA）, 4. 91% strains with very major errors （VME）, 2. 09% strains with major errors （ME）, 6.40% minor errors （MIE）. The AST for more than 90% of Enterobacteriaceae, nonfermenting bacteria, micrococci and streptococci were completed within 11 h, 13 h, 11 h and 12 h, respectively. The ESBLs tests for thirty-two strains by Vitek 2 Compact are all positive. Conclusions Vitek 2 Compact system can give rapid, reliable and reproducible result with high sensitivity and specificity in assessment of antimicrobial susceptibility testing for clinically relevant gram-negative and gram-positive bacteria, and would become a powerful tool in clinical microbiology laboratory.