【摘要】 目的研究下呼吸道铜绿假单胞菌的主要耐药机制超广谱β-内酰胺酶(ESBLs)和AmpC酶的产生情况。方法采用K-B试验,选用5种药敏纸片(IPM、CTX、CAZ、CTX/CLAV、CAZ/CLAV),参照相关标准,根据抑菌环特征推测ESBLs、AmpC酶的产生。结果114株下呼吸道铜绿假单胞菌中检出产ESBLs菌10株(8.8%),如果仅以CTX/CTX/CLAV为底物,检出7株(6.1%),以CAZ/CAZ/CLAV为底物检出5株(4.4%);产AmpC酶菌79株(69.5%);同时产ESBLs和AmpC酶菌4株(3.5%),产AmpC酶菌的检出率明显高于产ESBLs菌,差别具有显著性(P<0.05)。结论联合CTX/CTX/CLAV和CAZ/CAZ/CLAV两组底物可以提高铜绿假单胞菌ESBLs的检出率;下呼吸道铜绿假单胞菌AmpC酶产生率高,ESBLs产生率低;AmpC酶可能是下呼吸道铜绿假单胞菌对β-内酰胺类抗生素耐药的主要机制。更多还原

【Abstract】 OBJECTIVE To investigate the main drug-resistant mechanism of Pseudomonas aeruginosa in lower respiratory tracts,and the incidence of extended-spectrum beta-lactamases(ESBLs) and AmpC enzymes. METHODS We adopted K-B methods and selected 5 discs including IPM,CTX,CAZ,CTX/CLAV,CAZ/CLAV to detect ESBLs and AmpC enzymes according to relevant standards. RESULTS We detected 114 isolates of P.aeruginosa from lower respiratory tracts,10(8.8%) isolates of them were considered as ESBLs positive strains,only 7(6.1%) isolates were detected ESBLs if only using CTX/CTX/CLAV and 5(4.4%) isolates were detected ESBLs if only using CAZ/CAZ/CLAV.Seventy nine(69.5%) isolates were considered as producing AmpC enzymes.Four(3.5%) isolates were considered as both ESBLs and AmpC enzymes positive strains.The detective rate of producing AmpC beta-lactamases strains was higher than that of producing ESBLs strains.There was a significant difference between them. CONCLUSIONS The detective rate of ESBLs of P.aeruginosa may be improved by using both CTX/CTX/CLAV and CAZ/CAZ/CLAV.Among P.aeruginosa in lower respiratory tracts,the incidence of AmpC enzymes is very high,but the incidence of ESBLs is lower.AmpC beta-lactamase may be the main resistance mechanism of P.aeruginosa to beta-lactams in lower respiratory tracts.更多还原