新型洛菲不动杆菌的分离与鉴定

The isolation and identification of a novel strain of Acinetobacter lwoffi

目的对从呼吸道感染的分泌物中分离的1株革兰阴性球杆样细菌进行研究,探讨其种系发生及分类学特征。方法利用形态、生理、生化特性等表型性状进行初步鉴定,通过细菌16S rRNA基因测序及基因比对明确其种系来源。结果分离菌为革兰阴性球杆状菌,生化反应不活泼,对环丙沙星耐药;BLAST序列比对显示该分离菌与洛菲不动杆菌的相似度为99.2%,与洛菲不动杆菌标准株不同的是在底物利用试验上有8项结果存在差异。结论根据表型性状和种系发生结果证实该菌为洛菲不动杆菌,鉴于该菌株与模式株在生化特性方面存在一定差异,初步考虑该菌株为洛菲不动杆菌的新亚型。

Objective To taxonomically identify a Gram-negative coccobacillus strain isolated from respiratory tract secretions and to examine its phylogenic and taxonomic characteristics.Methods Initial identification was done using phenotypic characteristics such as morphological,physiological,and biochemical characteristics to ascertain the strain＇s phylogeny according to 16S rRNA gene sequencing and alignment.Results A short,plump,Gram-negative rod bacillus was isolated in a pure culture.The bacillus did not react biochemically.The isolated strain was resistant to ciprofloxacin.BLAST sequence alignment indicated that the isolated strain had a 16S rRNA gene sequence similarity（99.2%） to Acinetobacter Iwoffii,but there were disparities in eight substrate utilization tests.Conclusion The isolated strain was assigned to the species A.Iwoffii based on phenotypic characteristics and phylogeny analysis.Initial impressions are that the strain is a new subtype of A.Iwoffii in light of differences in biochemical characteristics in comparison to those of typed strains.