碳青霉烯类耐药鲍曼不动杆菌的耐药性及碳青霉烯酶基因型研究

Drug resistance and carbapenemases genotypes of carbapenem-resistant Acinetobacter baumannii

目的 研究碳青霉烯类耐药鲍曼不动杆菌的耐药性及碳青霉烯酶基因的携带情况.方法 连续收集2011年1月至2012年4月浙江省台州医院临床分离的碳青霉烯类耐药鲍曼不动杆菌75株.应用Vitek 2 Compact微生物鉴定仪进行细菌鉴定和药敏分析,并通过Hodge试验筛选产碳青霉烯酶的菌株,PCR扩增分析碳青霉烯酶的基因型.结果 75株碳青霉烯类耐药鲍曼不动杆菌均为多重耐药菌株,只对阿米卡星保持较高的敏感性,耐药率仅为13.3％ (10/75).其中,69株(92.0％)检测出OXA-23基因,67株(89.3％)检出OXA-51基因,未检出IMP、VIM和SIM酶基因.结论 产OXA酶是本组碳青霉烯类耐药鲍曼不动杆菌的主要耐药机制,其中OXA-23和OXA-51是主要基因型.

Objective To investigate drug resistance and carbapenemase genotypes of carbapenemresistant Acinetobacter baumannii.Methods A total of 75 clinical isolated strains of carbapenem-resistant Acinetobacter baumannii were collected from Taizhou Hospital in Zhejiang province during January 2011 and June 2012.Vitek 2 Compact microbial identification system was used for bacterial identification and drug susceptibility test,and modified Hodge test was used to screen strains producing carbapenemases.Genotypes of carbapenamases were determined by polymerase chain reaction.Results All 75 carbapenem-resistant Acinetobacter baumannii strains were resistant to most antibacterial agents except amikacin.The resistant rate to amikacin was 13.3％ (10/75).OXA-23 gene was positive in 69 strains (92.0％),and OXA-51 gene was positive in 67 strains (89.3％).No IMP,VIM and SIM gene was observed.Conclusion OXA enzyme is the main cause of drug resistance in this group of carbapenem-resistant Acinetobacter baumannii,and OXA-23 and OXA-51 genes are the most popular carbapenemnases coding genes.