目的 调查NDM-1基因在不动杆菌属菌株中的分布情况.方法 收集亚胺培南耐药的鲍曼不动杆菌25株、非鲍曼不动杆菌5株(分别为洛菲不动杆菌3株和琼氏不动杆菌2株).采用改良Hodge试验及双纸片协同试验进行碳青霉烯酶表型筛选;PCR和DNA测序方法检测碳青霉烯酶基因;接合试验探讨耐药基因的可传递性;PFGE调查菌株的同源性.结果25株鲍曼不动杆菌改良Hodge试验阳性10株,金属酶表型试验均阴性,均检出OXA-23-like基因,未检出NDM-1基因;5株非鲍曼不动杆菌金属酶表型试验均阳性,均携带NDM-1基因,改良Hodge试验均阴性;PFGE显示鲍曼不动杆菌同源性较高,主要为A克隆株,而NDM-1阳性菌株不具同源性.NDM-1阳性菌株接合试验未获成功.结论 本院碳青霉烯类耐药不动杆菌属菌株中NDM-1基因分布在非鲍曼不动杆菌中,且为散发.%Objective To investigate the distribution of NDM-1 in Acinetobacter spp. Methods Twenty-five isolates of Acinetobacter baumannii and 3 isolates of A. lwoffii and 2 isolates of A.junnii that were resistant to imipenem were selected for the study. Carbapenemases were screened by modified Hodge test and EDTA disk synergy test. The genotypes of carbapenamases were determined by PCR and DNA sequencing. Plasmid conjugation was performed to study the transfer of carbapenem resistance. Strain homology was analyzed by PFGE. Results Ten out of 25 A. baumannii strains were positive for MHT but all were negative for EDTA disk synergy test,and all the 25 strains were positive with OXA-23-like but negative for NDM-1. All the non-A.baumannii isolates were positive for EDTA disk synergy test but negative for MHT. The strains were just positive for NDM-1 detected by PCRs and negative for the other carbapenamases. The NDM-1 positive strains had different PFGE profiles. PFGE showed high homology for A.baumannii with mainly A clone. Conclusions NDM-1 was distributed in the bacterias rather than A. baumannii,which were resistant to imipenem and the positive isolates had different PFGE profiles.
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