狐源豚鼠气单胞菌M12的鉴定及致病性分析

为了鉴别豚鼠气单胞菌M12并研究其致病性，本试验利用管家基因gyrB鉴定菌种，然后采用家兔回肠体外器官培养（IVOC）和腿部肌肉注射两种方式探究该病原菌的致病机制，运用光学显微镜、电子显微镜、扫描电镜等多种手段从微观视角去研究M12的菌体结构、致病过程和感染组织的病理变化。结果显示，M12为两端钝圆的革兰氏阴性短杆菌，在电镜下观察发现该菌除鞭毛外细菌大小为（0.6~1.6）μm×（0.6~0.7）μm，鞭毛长度是菌体长度的2~3倍。该菌与GenBank上豚鼠气单胞菌的相似性高达100.0%。IVOC试验在扫描电镜下观察可以看到M12黏附在肠上皮细胞聚集成团，形成生物膜结构，肠上皮细胞破损；病理切片观察发现M12对家兔肠、肝脏、肺脏、肾脏、肌肉组织都有损伤。本试验结果可为豚鼠气单胞菌致病性的深入研究提供参考依据。

Identification and Pathogenicity Analysis of Aeromonas caviae M12 from Fox

We tried to identify the bacteria and explore the mechanism of the bacteria's pathogenicity via housekeeping gene gyrB and in vitro organ culture (IVOC) of ileum and intramuscular injection. Microscope, electron microscope and scanning electron microscope were also used to observe and the structure, pathogen of M12 and changes of infected tissues. The results showed that M12 was short gram-negative bacteria, and both ends of it were obtuse and the size without flagellum was (0.6 to 1.6) μm×(0.6 to 0.7)μm while length of flagellum was about 2 to 3 times of the length of bacteria.It had 100.0% similarity with Aeromonas caviae from GenBank. IVOC test observed M12' adhesion in intestinal epithelial cell, resulting in formulation of biofilm structure and damage in intestinal epithelial cell. Histopathologic examination showed that M12 could cause damage in intestine, liver, lung, kidney, muscle tissue of rabbit.The assay would offer references for researching the pathogenic mechanism of Aeromonas caviae.