BACTEC MGIT 960系统在分枝杆菌属菌种初步鉴定及药敏中的应用

Application of BACTEC MGIT 960 system in preliminary identification of mycobacterium and antimicrobial susceptibility test

目的评价BACTEC MGIT 960系统在分枝杆菌属菌种鉴定及药敏中的应用价值。方法显微镜观察BACTEC MGIT 960系统分离的162株分枝杆菌在液体培养基中的形态,传统生化和核酸检测法同时鉴定分枝杆菌属菌种,分析细菌形态与菌种之间的关系;应用BACTEC MGIT 960系统对分离的141株结核分枝杆菌进行药敏试验。结果 162株分枝杆菌属在MGIT液体培养基中呈索条状、分枝状、点粒状和分散状4种形态;呈索条状132株分枝杆菌属均为结核分枝杆菌,呈点粒状10株和分散状6株分枝杆菌属均为非结核分枝杆菌;对链霉素、异烟肼、利福平和乙胺丁醇的耐药率分别为9.9%、14.2%、9.2%和6.4%,总耐药率18.4%,同时耐利福平和异烟肼的为8.5%;药敏平均检测时间为9.3 d。结论 BACTEC MGIT 960系统可快速将分枝杆菌属初步鉴定为结核分枝杆菌和非结核分枝杆菌,能快速准确获得临床一线抗结核药物的药敏结果。

OBJECTIVE To evaluate the application of BACTEC MGIT 960 system in mycobacterium identification and antimicrobial susceptibility test.METHODS The growth forms of 162 strains in liquid media were observed with microscope.Mycobacterium strains were identified by real-time PCR and traditional biochemistry method.The relation between bacteria form and strain categarly was analyzed.The susceptibility testing of Mycobacterium tuberculosis of 4 major antituberculosis drugs were detected with BACTEC MGIT 960 system.RESULTS Four growth forms of cording,clump and branch,load and scatter,and coccoid form were observed from 162 strains in liquid media.Among these,132 strains of cording form were all M.tuberculosis,10 strains of coccoid and 6 strains of load and scatter form were all nontuberculosis mycobacteria.Of the 141 strains mycobacterium tuberculosis complex,the rate of multi-drug resistance（MDR）-TB was 8.5%,the drug resistance rate of streptomycin,isoniazid,rifampicin and ethambutol were 9.9%,14.2%,9.2% and 6.4% respectively.The mean time of antimicrobial susceptibility test was 9.3 days.CONCLUSION System is quick and accurate to identify mycobacterium strains and acquire antimicrobial susceptibility results.