产超广谱β-内酰胺酶及AmpC酶的阴沟肠杆菌的耐药性分析

目的 分析产超广谱β-内酰胺酶（extended spectrum β lactamases,ESBLs）及AmpC酶的阴沟肠杆菌的分布情况及耐药特征.方法 选择49株阴沟肠杆菌,采用纸片扩散法进行药物敏感试验,按美国临床实验室标准化协会推荐的确证试验检测产ESBLs阳性菌株；头孢西丁纸片扩散法初步筛选产AmpC酶阳性菌株,采用PCR检测AmpC酶基因.结果 抗生素敏感试验结果显示阴沟肠杆菌对头孢西丁、替卡西林/克拉维酸、头孢曲松、氨曲南的耐药率均达79.6％以上,对美罗培南敏感率较高,达91.8％.49株阴沟肠杆菌中对头孢西丁耐药的菌株46株（93.9％）；产ESBLs菌株29株（59.2％）,PCR 扩增产AmpC酶的阴沟肠杆菌36株（73.5％）,同时产两种酶的菌株为13株（26.5％）.结论 产ESBLs 及AmpC酶阴沟肠杆菌普遍且耐药现象严重.

The drug resistance analysis of Enterobacter cloacae which produce AmpC and ESBLs

Objective To analysis the distribution and drug resistance characteristic of Enterobaeter cloacae producing AmpC and extended spectrum β- lactamases （ESBLs）. Methods 49 strains Enterobaeter cloacae were collected. The confirmatory test recommended by clinical and laboratory standards institute was carried out to detect ESBLs and the Kirby-Bauer method was used to determine drug sensitivity. AmpC positive strains were screened by cefoxitin disk diffusion method and the AmpC gene were detected by PCR. Results Antibiotics susceptibility test showed that the resistant rate of Enterobacter cloacae to cefoxitin, ticarcillin-CA, ceftriaxone, aztreonam were all above 79.6%. Enterobacter cloacae were sensitive to meropenem and the sensitive rate was 91.8%. There were 46 strains （93.9%） Enterobacter cloacae resistant to cefoxitin. There were 29 strains （59.2%） Enterobaeter cloacae producing ESBLs. There were 36 strains （73.5%） producing AmpC by PCR ampli- fication and 13 strains （26.5%） producing both ESBLs and AmpC at the same time. Conclusion Enterobacter cloacae producing ESBLs and AmpC are prevalent and the drug resistance phenomenon is serious.