宁夏某肉牛场牛支原体分离鉴定及病理组织学观察

Isolation and Identification of Mycoplasma bovis and Its Histopathological Observation in a Beef Cattle Farm of Ningxia

为了分离鉴定宁夏某肉牛场牛支原体和分析该病原对靶器官的损伤,采用Thiaucourt's液体筛选培养基和固体培养基进行病原分离,设计牛支原体16SrRNA通用引物和uvrC特异性引物进行基因序列扩增并测序,使用DNA Star软件将分离菌株测序结果与GenBank中的标准株序列进行同源性比较,采用MEGA6.0软件中的邻接法(Neighbor-joining,NJ)依据16SrRNA和uvrC序列构建分离株系统发育树并进行遗传进化分析,采用石蜡切片,HE染色,病理组织学观察。结果表明,病原菌落呈油煎蛋样,16S rRNA和uvrC扩增片段与阳性对照一致,16S rRNA和uvrC基因序列构建的系统发育树与牛支原体在同一分支;肺组织结构消失,部分肺泡腔实变、塌陷,局灶性肺出血,肺泡腔内可见炎性细胞浸润;肺泡隔增厚、出血,肺泡内有少量脱落的上皮细胞;肺泡壁断裂,肺泡腔可见红色的炎性渗出物,有纤维结缔组织增生。

For isolation and identification of Mycoplasma bovis and analysis of target organ damage in a beef cattle farm of Ningxia,this study used Thiaucourt＇s liquid filter medium and solid medium to isolate pathogens,designed universal 16S rRNA primers and uvrC specific primers of Mycoplasma bovis to amplifiy and sequence the gene,used DNA Star software to compare the sequence of the isolated strain and the standard strains in GenBank,and MEGA6.0software Neighbor-joining method to construct and analyze phylogenetic tree of isolates based on 16S rRNA and uvrC sequences,and used paraffin section technology and hematoxylin-eosin staining for histopathological observation.The results showed that the bacterial colony looks like ＂fried egg＂,16 S rRNA and uvrC amplified fragments were consistent with the positive control,phylogenetic trees constructed based on 16S rRNA and uvrC gene sequences were in the same branch with Mycoplasma bovis;lung tissue structure disappeared,part of alveolar consolidation and collapse,focal pulmonary hemorrhage,alveolar infiltration with inflammatory cells;thickening of alveolar septa,shedding of a small amount of alveolar epithelial cells;alveolar wall fracture,alveolar inflammatory exudate,fibrous connective tissue proliferation.