乌鲁木齐地区耐碳青霉烯鲍曼不动杆菌碳青霉烯酶基因型及同源性分析

摘要

目的 探讨乌鲁木齐地区临床分离的对亚胺培南耐药的鲍曼不动杆菌耐药性、同源性和碳青霉烯酶型.方法 收集42株对亚胺培南耐药的鲍曼不动杆菌,采用纸片扩散法测定亚胺培南耐药菌对18种抗菌药物的敏感性,采用PCR方法扩增碳青霉烯酶基因型包括OXA-23,OXA-24,OXA-58,IMP和VIM型.采用随机扩增多态性DNA(RAPD)分析同源性.结果 42株对亚胺培南耐药的鲍曼不动杆菌对阿米卡星耐药率最低(28.5%),左氧氟沙星、庆大霉素、头孢他啶耐药率均为53.6%,头孢哌酮/舒巴坦耐药率为39.3%,其余抗菌药物耐药率均大于80.0%;RAPD分型发现42株对亚胺培南耐药的鲍曼不动杆菌属于6个型,其中以A型(8株)、D型(20株)和F型(6株)3个型为主.42株对亚胺培南耐药的鲍曼不动杆菌有33株携带 OXA-23组基因,未检测到金属酶基因.结论 耐亚胺培南鲍曼不动杆菌的耐药现象非常严重,临床应根据药敏结果合理选用抗生素,克隆播散是对亚胺培南耐药的鲍曼不动杆菌最主要的传播方式,OXA-23型是最主要的碳青霉烯酶基因型.%Objective To identify the antibiotic resistance,homology and the carbapenemases genotypes of imipenem-resistant strains of Acinetobacter baumannii isolated from the Urumqi region. Methods 42 imipenem-resistant strains of Acinetobacter baumanu were isolated from the first affiliated bospital of Xinjiang Medical University from August 2009 to April 2010. The drug susceptivity of imipenem-resistant strains to 18 antimicrobial agents were determined by K-B method. The homology of these isolates was analysed by random amplified polymorphic DNA(RAPD). The genotypes of carbapenamases were determined by PCR. Results The resistant rates of 42 isolates of Acinetobacer baumannii to Amikacin were the lowest(28. 5％). The resistance rates to levofloxacin,cidomycin and ceftazidime all were 53. 6 ％　 and that to cefoperazone/sulbactam was 39. 3％. The resistant rates to other antimicrobial agents were more than 80 ％ . RAPD showed that 42imipenem-resistant strains of Acinetobacter baumanii belong to six types. The main were A type ,D type and F type. 33 isolates were positive for OXA-23 gene. Conclusion The phenomenon of resistance in imipenem-resistant strains of Acinetobacter baumannii is serious.The clinic should be choose antibiotics according to drug resistance. Clone dissemination seems to be the most important way of strains spread. OXA-23-like gene are the most popular carbapenemases coding genes in imipenem-resistant Acinetobacer baumannii in the first affiliated hospital of xinjiang medical university.