一株牛支原体的分离鉴定及致病性初步研究

Identification of a Mycoplasma bovis and the Initial Virulence Analysis in Cattle

关键词:  牛支原体  分离  鉴定  毒力

Key words:  Mycoplasma bovis  isolation  identification  virulence

摘要:

对采集到的疑似牛支原体肺炎肺组织病料进行病原的分离，并对分离株进行形态学、生化和分子生物学鉴定，结果显示成功分离获得1株牛支原体，命名为NM001。该分离株的菌落形态呈典型的“荷包蛋状”，不能发酵葡萄糖，不能水解精氨酸，不分解尿素。PCR能够扩增出牛支原体特异的P48基因条带，16S rRNA基因序列与Ningxia-1序列同源性为99.03%。将该分离株接种2头6月龄犊牛均出现明显的临床症状，剖检后胸腔中少量淡黄色渗出液，肺脏出现肉样实变。试验结果表明，分离到的牛支原体NM001株对牛具有较强的毒力，为牛支原体攻毒模型的建立奠定了基础。

Abstract:

The suspected lung tissue samples were collected to isolate and identify pathogens by both morphological，biochemical and molecular techniques. Results showed that one strain of Mycoplasma bovis, designated as NM001, with typical fried-egg shape grown on solid medium was successfully isolated. NM001 could not ferment glucose, not hydrolyze arginine, and not decompose urea. An expected gene fragment of P48 for Mycoplasma bovis was amplied by PCR. Sequence analysis of the 16S rRNA gene revealed that NM001 has an identity of 99.03% with Ningxia-1 strain. Then two 6-month-old calves were intratracheally injected to analyse the initial virulence of NM001.Both calves inoculated with NM001 showed obvious clinical symptoms and necropsy symptom with a small amount of yellow fluid in the pericardial cavity. Moreover, clarification parenchyma appeared in different part of lung. These data suggested that one Mycoplasma bovis strain NM001 was successfully isolated with strong virulence to cattle, which provides a good infection model for Mycoplasma bovis virulence research.