铜绿假单胞菌诱导型β-内酰胺酶的分类检测及其临床意义

Classification and Detection of Inducible β-Lactamases Produced by Pseudomonas aeruginosa and Their Clinical Significance

目的 了解铜绿假单胞菌 (PA )所产的各种诱导型β-内酰胺酶 (诱导酶 )的分布情况。方法 采用亚胺培南诱导 +多底物相邻纸片法。结果 PA标准株为产诱导型超广谱酶 (IESBL s) ;10 0株 PA临床株中产各种诱导酶93株 (93.0 % ) ,其中 IESBL s 92株 (98.9% ) ,诱导型青霉素酶 1株 ;93株 PA产诱导酶临床株中 ,以头孢噻肟(CTX)、哌拉西林 (PIP)、氨曲南 (ATM)、头孢他啶 (CAZ)为作用底物的菌株依次为 5 3株、6 0株、74株、77株 ,未出现以头孢呋辛 (CXM)、头孢唑林 (CFZ)为作用底物的诱导酶菌株 ;92株 PA产 IESBL s有 10种表型。结论 PA标准株为产 IESBL s;PA绝大多数产 IESBL s,PA产其他类型诱导酶很少 ;不同菌株产诱导酶的底物也不同 ,CAZ的筛选率最高 ;PA所产 IESBL s至少有 10种。

OBJECTIVE To study the significance of classification and distribution of the inducible β lactamases (IBLs) produced by Pseudomonas aeruginosa (PA). METHODS The isolates were detected by imipenem+multi substrates method. RESULTS The standard strain (ATCC27853) produced the inducible extended spectrum β lactamases (IESBLs)of PA; from the 100 clinical strains of PA 93 (93.0%) produced the IBLs, one of them produced the inducible penicillinases, other 92 strains produced IESBLs (98.9%) with 10 phenotypes. The strains with cefotaxime, piperacillin, their active substrates aztreonam and ceftazidime were 57.0%, 64.5%, 79.6%, 82.8%, respectively. CONCLUSIONS the standard PA strain (ATCC27853) only produced the IESBLs; The clinical strains produced IESBLs and few produced other types of IBLs. The screening rate of CAZ was the highest. More than 10 types of IESBLs produced by PA were detected.