烧伤创面多重耐药鲍氏不动杆菌同源性和碳青霉烯酶基因型及整合子研究

目的 明确甘肃省人民医院烧伤病房多重耐药鲍氏不动杆菌的耐药性、同源性及与整合子的关系. 方法 31株多重耐药鲍氏不动杆菌分离自该院烧伤住院患者创面分泌物标本.采用琼脂稀释法测定鲍氏不动杆菌对11种抗菌药物的最低抑菌浓度(MIC);脉冲场凝胶电泳(PFGE)分析菌株的同源性:PCR扩增I、Ⅱ、Ⅲ类整合酶及整合酶阳性菌株的整合子基因盒,进行序列分析;分析亚胺培南耐药菌株的碳青霉烯酶基因型. 结果 鲍氏不动杆菌对亚胺培南、美罗培南、哌拉西林/他唑巴坦和头孢哌酮/舒巴坦的耐药率分别为45.2%、48.4%、48.4%、41.0%,对头孢他啶、头孢吡肟、环丙沙星、阿米卡星、庆大霉素、氨曲南和哌拉西林的耐药率均在80.0%以上.所有菌株PFGE分型共分为A、B、C 3型,A克隆18株、B克隆7株、C克隆6株.20株细菌整合子扩增阳性,携带有aadA1、aadA5、aacA4、aac3、aacC1、aac(6')-Ib、catB8、drfA17和drf8基因,介导对氨基糖苷类抗生素、氯霉素、甲氧苄啶的耐药.14株亚胺培南耐药的菌株均产OXA-23型碳青霉烯酶. 结论 多重耐药鲍氏不动杆菌在该院烧伤病房播散,以A克隆为主;鲍氏不动杆菌整合子主要介导对氨基糖苷类抗生素及氯霉素的耐药性,碳青霉烯类抗生素耐药鲍氏不动杆菌均产OXA-23型碳青霉烯酶.

Detection of integron,homology and genotype of carbapenemases in multi-drug resistant Acinetobacter Baumannii isolated from burn wound

Objective To investigate the relationship among antibiotic esistance,integron,homology of multi-drug resistant Acinetobacter Baumannii isolated from burn ward. Methods hirty-one strains of multi-drug resistant Acinetobacter baumannii were isolated from samples of burn wound exudate in hospitalized patients of Gansu Province People's Hospital.The minimum inhibitory concentrations(MIC)of these strains against 11 zntibiotics was examined by agar dilution mehod.Homology of these strains was analyzed by pulse-field gel electrophoresis(PFGE).Class 1,2 and 3 integrase,integron genes and genotype of carbapenemases were amplified by PCR and verified by DNA sequencing. Results Acinetobacter baumannii were highly resistant to all antibiotics except imipenem,meropenem,cefoperazone-sulb-actam,piperacillintazobactam(antibiotic resistance rate was 45.2%.48.4%,48.4%,41.0%,respectively).All strains were classified into 3 types of clones(A,B,C clone included 18,7,6 strains respectively)based on PFGE pattern.Integrons of 20 strains of Acinetobacter Baumannii harbored aadA1,aadA5,aacA4,aac3,catB8,aacC1,aac(6')-Ib,drfA17 and drf8 gene. Conclusion Multi-drug resistance Acinetobacter baumannii (major in clone A)spread widely in burn ward of Gansu Province People's Hospital.Integrons of Acinetobacter baumannii mediated drug resistance against aminoglycoside antibiotics,chloram-phenicol.All carbapenem-resistant Acinetobacter Baumannii can produce OXA-23 carbapenemase.