武汉地区医院内感染阴沟肠杆菌耐药监测及现状分析

Current Status and Resistance of Enterobacter Cloacae in Nosocomial Infection in Wuhan

目的了解近两年武汉地区四家教学医院院内感染阴沟肠杆菌耐药现状,以及去阻遏持续高产AmpC酶和超广谱β-内酰胺酶(ESBLs)及同时表达这两类酶的发生率。方法收集武汉地区四家医院558株医院内感染阴沟肠杆菌,用Kirby-Bauer法对15种抗菌药物进行药物敏感试验,并用改良的酶提取物三维试验法,检测阴沟肠杆菌去阻遏持续高产AmpC酶,用改良双纸片法检测ESBLs。结果阴沟肠杆菌仅对亚胺培南、头孢吡肟显示较好的敏感性。三维试验和表型筛选试验表明,558株实验茵中,65(11.6%)株持续高产AmpC酶,135(24.2%)株产ESBLs,28(5.0%)株同时表达这两种酶。结论阴沟肠杆菌对常用抗生素耐药现象较严重,耐药性呈上升趋势。高产AmpC酶和ESBLs的阴沟肠杆菌在四家教学医院的分离率较高。对阴沟肠杆菌进行耐药性监测及去阻遏持续高产AmpC酶和ESBLs检测,能较好了解该地区细菌耐药的现状,为当地临床医生抗生素的使用提供合理建议。

Objective To estimate the occurrence of derepressed hyperproduction AmpC β-lactamases,extended-spectrum β-lactamases（ESBLs）and dual enzyme expression ,as well as drug resistance profile in Enterobacter cloacae（E, cloacae）isolates at large hospitals in Wuhan. Methods 558 E. cloacae isolates were collected by a clinical laboratory from four teaching hospitals in Wuhan,China,from 2005 to 2006. Resistance to 15 antibiotics in these isolates was assessed with Kirby-Bauer method. Modified three-dimensional extract test and modification of the double-disk test were used to detect hyperproduction AmpC β-lactamases and ESBLs,respectively. Results All isolates were found to be highly sensitive to Imipenem and Cefepime. Among 558 isolates, 65 （11.6 ~ ）isolates produced hyperproduction AmpC β-lactamases, 135 （24.2 ~ ） iso- lates produced ESBLs,and 28（5.0%）produced both enzymes. Conclusion These results indicate an increased prevalence of resistance among E. Cloacae isolates in Wuhan to either hyperproduction AmpC β-lactamases or ESBLs,or both. It is very important to provide correct suggestions to clinical doctors in antibiotics,and to prevent and control the nosocomial infection.