4种酶抑制剂分类检测碳青酶烯酶的研究

Carbapenemases-producing Gram-negative Bacteria Detected and Classificated by Using Four Beta-lactamases Inhibitors

目的 研究联合应用EDTA、二巯基乙酸 ( 2MA)、克拉维酸 (CLAV)和舒巴坦 (SUL) 4种 β 内酰胺酶抑制剂建立分类检测碳青酶烯酶 (CHBls)的简便实用方法。方法 采用多底物纸片 多抑制剂协同法 (MDMIST)分类检测 4 6株碳青酶烯类抗生素耐药的临床分离株 (铜绿假单胞菌 2 0株 ,嗜麦芽寡养单胞菌 12株 ,黄杆菌属 7株 ,不动杆菌属 5株 ,普罗威登斯菌属 2株 )的CHBls。结果 对多数菌 ,2MA检出率最高 ,但在铜绿假单胞菌以EDTA最高 ;CLAV、SUL检出率没有 2MA、EDTA高 ;2MA在嗜麦芽寡养单胞菌、普罗威登斯菌属、黄杆菌属中检出率最高 ,EDTA在铜绿假单胞菌中最高 ,SUL在不动杆菌最高 ;不同底物间 ,一般IMP检出率最高 ,但在黄杆菌属 ,CAZ最高 ;在 3种细菌 ,存在IMP敏感 /MER耐药表型 ,该表型多为SCHBLs ,少数为其他机制。结论 MDMIST简便实用 ;不同酶抑制剂在不同种菌间及同种菌中的检出率不同 ;不同菌所产的CHBLs的优势类型不同 ;不同底物检出率不同。

OBJECTIVE To study the detection and classification of the carbapenemases producing Gram negative bacteria by using four beta lactamases inhibitors [clavulanate(CA), 2 mercaptopropionic acid(2MA), sulbactam(SUL) and EDTA]. METHODS To detect the carbapenemases (CHBls)produced by 46 strains of resistant to carbapenem Gram negative bacteria (Stenotrophomonas maltophilia 12 strains, Acinetobacter 5 strains, Pseudomonas aeruginosa 20 strains, Flavobacterium 7 strains, Providencia 2 strains)by using a multidisk multi inhibitor synergy test (MDMIST). RESULTS In majority strains, the detective rate of 2MA was the highest, but EDTA was the highest in P. aeruginosa, SUL highest in Acinetobacter. In the disks, the detective rate of IMP was the highest, but CAZ was the highest in Flavobacterium; there was a phenotype of ”imipenem susceptibility/meropenem resistant ” which was mainly SCHBLs in three bacteria species. CONCLUSIONS The MDMIST is convenient and simple for detecting CHBls, the detective rate of four beta lactamases inhibitors is different; the main type of CHBls in various bacteria species is different; the detective rate of disks is different.