OXA-23酶基因在多药耐药鲍氏不动杆菌的流行研究

Prevalence of OXA-23carbapenemase gene in multidrug-resistant Acinetobacter baumannii

目的了解临床分离的多药耐药鲍氏不动杆菌(MDRAB)中OXA-型β-内酰胺酶基因在医院存在状况,探讨MDRAB的耐药机制。方法收集2009年1月-2010年12月临床分离的MDRAB,采用纸片扩散(K-B)法再次测定MDRAB对各类抗菌药物的敏感性;采用PCR法检测OXA-23群、OXA-24群、OXA-58群基因。结果除头孢哌酮/舒巴坦外,22株分离株对β-内酰胺类抗菌药物均表现为耐药,对亚胺培南与美罗培南的耐药率分别达到了63.6%、36.4%;PCR检测OXA-23群基因,22株均呈阳性,但其他碳青霉烯酶基因均为阴性。结论临床分离的鲍氏不动杆菌对β-内酰胺类抗菌药物耐药性非常严重,且OXA-23群基因携带率高达100.0%,分离株的耐药性可能与OXA-23碳青霉烯酶有关。

OBJECTIVE To understand the existence status of OXA β-lactamases genes in clinical isolates of multi-drug-resistant Acinetobacter baumannii（MDRAB） in our hospital and explore the drug-resistant mechanism of MDRAB.METHODS The MDRAB isolates were collected from Jan.2009 to Dec.2010.The drug susceptibility was determined by K-B method.The resistance genes of OXA-23 group,OXA-24 group and OXA-58 group were detected by PCR.RESULTS Totally 22 isolates showed resistance to β-lactam antibiotics except for cefperazone-sulbactam.Resistance rates to imipenem and meropenem reached 63.6% and 36.4% respectively.22 isolates were positive for OXA-23 genes and the other carbapenemases genes were negative.CONCLUSION The drug resistance to β-lactam antibiotics against Ab was very serious.The detection rate of the genes of OXA-23 group achieved as high as 100%.Therefore,the drug resistance of clinical isolates may be related to OXA-23 carbapenemase.