摘要
[目的]了解鲍曼不动杆菌的OXA-碳青霉烯酶基因分布情况及插入序列1(ISAba1)对OXA-23基因表达的影响。[方法]收集临床分离的鲍曼不动杆菌无重复株110株。多重PCR扩增OXA-23-like、OXA-24-like、OXA-51-like、OXA-58-like基因,并测序;应用肠杆菌科基因组内重复序列ERIC-PCR进行同源性分析。PCR扩增OXA-23、OXA-51、ISAba1-OXA-23和ISAba1-OXA-51,并用大肠杆菌TOP10进行转化OXA-23、ISAba1-OXA-23、OXA-51。琼脂稀释法测定阳性菌株和转化子TOP10(pGM-OXA)对亚胺培南的MIC值。[结果]在上述临床菌株中PCR检测出blaOXA-23、blaOXA-51、blaOXA-58I、SAba1-OXA-23,未检测到blaOXA-24I、SAba1-OXA-51;110株鲍曼不动杆菌来自18个不同克隆株;转化子TOP10(pGM-ISAba1-OXA-23)MIC值为0.5,另一转化子TOP10(pGM-OXA-23)MIC值为0.125,TOP10(pGM-OXA-51)MIC值为0.25,三者均未显示对亚胺培南高水平耐药的特性。[结论]OXA-碳青霉烯酶基因在鲍曼不动杆菌中广泛存在,以OXA-23、OXA-51为主;同时携带OXA-23和OXA-51两种基因的鲍曼不动杆菌较多见;ISAba1位于OXA-23基因的上游;其在大肠杆菌中并未对OXA酶的表达产生大的影响。
[ Objective] To study the distribution of OXA genes of A. baumanii and the effect of ISAbal on gene expression of OXA- 23. [ Methods] A total of 110 non- replicate Acinetobacter baumannii strains were isolated from clinical speci- mens. OXA -23 - like, OXA -24 - like, OXA - 51 - like, OXA - 58 - like genes were amplified by multiplex PCR. The PCR products were sequenced. Homology was analyzed by ERIC - PCR. OXA - 23, OXA - 51, ISAbal - OXA - 23 and ISAbal -OXA -51 were amplified by PCR. OXA -23, ISAbal -OXA -23 and OXA -51 were transformed into Escherichia coli TOP10. The minimal inhibitory concentrations （MIC） of the positives isolates and the products of the transformation to Imipenem were determined using ager dilution. [Results] The genes blaoxA_~, blaoxA_5~, blaoxA_ss, ISAbal -OXA -23 except blaoxA_u and ISAbal -OXA- 51 were detected in the clinical strains by PCR. One hundred and ten strains of acine- tobacter banmannii came from 18 different clones. MIC of the transformation TOP10 （pGM - ISAbal -OXA -23 ） was 0.5,while the MIC of the other TOPIO （pGM - OXA -23）was O. 125, and the MIC of the other TOP10 （ pGM - OXA -51 ） was 0.25. Three of them did not exhibit high - level resistance to Imipenem. [ Conclusions ] OXA genes are widespread in A. baumanii, most of them are OXA - 23 and OXA - 51. Acinetobacter baumannii with OXA - 23 gene and OXA - 51 gene are more common in clinic. ISAbal is in upstream OXA - 23, it does not affect the express of OXA -23 so much when it is in Escherichia coli.
出处
《大连医科大学学报》
CAS
2011年第6期590-594,共5页
Journal of Dalian Medical University
