产超广谱β内酰胺酶细菌的耐药性监测

目的通过对本地区产ESBLs细菌的检测,比较产ESBLs与非产ESBLs大肠埃希菌和克雷伯菌的耐药性,补充体外药敏试验的不足,更好地指导临床合理有效的选择抗菌药物.方法细菌鉴定采用法国生物梅里埃公司API鉴定系统和手工法;结果判断按NCCLS 2000年版标准执行;数据统计分析采用上海金仕达软件;产ESBLs细菌的检测采用双纸片协同法和NCCLS推荐的纸片扩散初筛法及酶抑制剂增强试验纸片扩散确认法.结果产ESBLs大肠埃希菌和克雷伯菌的检出率分别为13.2%和10.2%;产ESBLs菌株的耐药性明显高于非产ESBLs菌株;产ESBLs菌株耐药率较低的有亚胺培南和头孢哌酮-舒巴坦,其次为阿米卡星;产ESBLs菌对部分第三代头孢菌素类抗菌药物仍表现为体外敏感.结论对产ESBLs细菌的感染,单纯根据体外药敏试验结果对头孢菌素类的敏感性选择抗菌药物,会误导和延误治疗,实验室应开展产ESBLs细菌的检测;产ESBLs细菌呈多重耐药,其耐药性明显高于非产ESBLs菌株,治疗宜选碳青霉烯类和头孢哌酮-舒巴坦.

Surveillance of antibiotic resistance in bacteria producing extended-spectrum beta-lactamases

Objective The prevalence and antibiotic resistance of ESBLs-producing and non-ESBLs-producing E. coli and Klebsiella spp. were compared to supplement the in vitro susceptibility testing and guide better antibiotic selection for clinical therapy. Methods The isolates were identified by API system and conventiona method. The data were interpreted according to NCCLS standard 2000 edition. Statistical analysis was conducted with Shanghai Kingstar software. The ESBLs-produclng bacteria were screened by double-disk method and initial screening method recommended by NCCLS, and confirmed by inhibitor-potentiated disk diffusion method. Results The ESBLs-producing strains accounted for 13.2% in E. coli and 10.2% in Klebsiella spp. Antibiotic resistance rates of ESBLs-producing strains were significantly higher than those of non-ESBLs-pro- ducing E. coli. Imipenem and cefoperazone-sulbactam were relatively less resistant to ESBLs-producing E. coli, followed by amikacin. ESBLs-producing strains seemed sensitive to some of the third generation cephalosporins in vitro. Conelusions Antibacterial therapy dependent on the data of susceptibility testing alone may mislead and delay the right management of patients with infections caused by ESBLs-producing strains. Clinical microbiology laboratory should provide data of ESBLs-producing bacteria. ESBLs-producing strains are mostly multi-resistant, and significantly more resistant than non-ESBLs-producing strains. Carbapenems and cefoperazone-sulbactam are the first choice for infections caused by ESBLs-producing bacteria.