鸡源圣雷利气单胞菌(Aeromonas sanarellii)的分离鉴定及致病性研究

Isolation,identification and the pathogenicity of Aeromonas sanarellii from chicken

对1例鸡鼻炎样病例进行细菌学诊断,从病鸡鼻腔中分离到1株革兰阴性杆菌,编号为ZY17105,对其进行形态学、生理生化、分子生物学鉴定,对其致病性和耐药性进行分析,同时探讨gyrB基因在气单胞菌鉴定中的意义。16S rDNA进化分析显示ZY17105与圣雷利气单胞菌模式菌株LMG24682同源性为99.4%;gyrB基因进化分析显示ZY17105与各圣雷利气单胞菌株形成同一进化支,与圣雷利气单胞菌模式菌株LMG24682和A2-67之间的同源性为分别为97.8%和98.2%。根据形态学、生理生化特性、16S rDNA和gyrB基因进化分析,将分离株ZY17105鉴定为圣雷利气单胞菌,分离株ZY17105对小鼠和鸡有较强致病性;另外,进化分析表明gyrB基因在气单胞菌属各种间的区分能力高于16S rDNA。本研究首次从中国大陆分离到圣雷利气单胞菌,并证实gyrB基因可替代16S rDNA用于气单胞菌属各菌种间的进化分析鉴别。

To bacteriologically diagnose the a chicken coryza-like disesae,a Gram negative bacillus,designed as ZY17105,was isolated from the nasal cavity,and the morphological identification,biological characterization identification and molecular identification,animal artificial infection,antibiotic susceptibility of ZY17105 were carried out;meanwhile the role of gyrB gene in discrimination the species of the genus Aeromonas was studied.Phylogenetic analysis of the 16 S rDNA indicated that strain ZY17105 shared 99.4% sequence similarity with the Aeromonas sanarellii type strain LMG 24682.Phylogenetic analysis of gyrB gene indicated that strain ZY17105 formed a monoclade and shared 97.8% and 98.2% sequence similarity with the Aeromonas sanarellii type strain LMG24682 and the strain A2-67,respectively.Based on these results the strain ZY17105 was identified as Aeromonas sanarellii,animal artificial infection indicated that the strain ZY150911 was pathogenic to mice and chicken;moreover,the gyrB gene showed a higher capacity for discrimination of the species of the genus Aeromonas than the 16 S rDNA.To our knowledge,this is the first isolation of Aeromonas sanarellii from China's Mainland.Our results also confirmed that the gyrB gene can supersede the 16 S rDNA in phylogenetic discrimination of the species of the genus Aeromonas.