鲍氏不动杆菌的耐药性分析及β-内酰胺类耐药基因的初步研究

Drug resistance of acinetobacter baumannii and preliminary study on β-lactam resistance genes

目的分析临床分离的鲍氏不动杆菌耐药性,研究耐亚胺培南菌株的碳青霉烯酶基因型。方法利用VITEK-2系统检测85株鲍氏不动杆菌的药物敏感性,聚合酶链反应(PCR)技术检测耐亚胺培南菌株的碳青霉烯酶基因型。结果 85株鲍氏不动杆菌对氨苄西林的耐药率最高,为94.1%,对亚胺培南的耐药率为64.7%;亚胺培南的耐药的菌株中携带OXA-23基因有46株,占83.6%,携带OXA-64-like基因有32株,占58.2%,携带OXA-58基因有13株,占23.6%,以上阳性产物经测序比对与GenBank提供的标准序列99.0%同源;其余OXA-20、OXA-24、OXA-48基因型检测结果均为阴性。结论医院检测的鲍氏不动杆菌对β-内酰胺类耐药严重,并以携带OXA-23基因型碳青霉烯酶为主。

OBJECTIVE To analyze the antibiotic resistance of Acinetobacter baumannii isolated from clinical patients,and to study on the carbapenemase genotype of imipenem-resistant strains.METHODS The VITEK 2 identification system was used for the identification and susceptibility test of the 85 bacterial isolates,the polymerase chain reaction（PCR） was used to detect the carbapenemase genotype of imipenem-resistant strains.RESULTS Among 85 strains of A.baumannii,the drug resistance to ampicillin was the highest（94.1%）,and the drug resistant rate to imipenem was 64.7%.There were 46 bacterial isolates（83.6%） carried carbapenemase OXA-23 gene,32（58.2%） isolates carried OXA-64-like gene and 13（23.6%） isolates carried OXA-58 gene.The gene-positive strains were randomly selected and sequenced,and these isolates were found to be homologous（99.0%） with the standard sequences provided from GenBank.The remaining OXA-20,OXA-24 and OXA-48 genes were negative.CONCLUSION The resistance of A.baumannii to β-lactam antibiotics is serious,and most of the isolates carry OXA-23-type carbapenemase gene.