猪霍乱沙门氏菌的快速分离鉴定

Rapid isolation and identification of Salmonella choleraesuis

猪霍乱沙门氏菌是引起仔猪副伤寒的主要病原菌,给养猪业造成重大危害。本文旨在建立一套细菌快速分离鉴定方法,为该病流行病学调查提供有效手段。从临床初诊为仔猪副伤寒的病猪采集粪便,接种亚硒酸盐亮绿增菌液增菌后,划线于SS琼脂培养基,挑无色透明菌落纯化。纯化菌落用美国B IOLOG自动细菌鉴定仪GN2肠杆菌鉴定板鉴定,同时用常规生化鉴定管鉴定,结果符合猪霍乱沙门氏菌的生化特征。PCR扩增invA基因,测序鉴定PCR产物,结果与猪霍乱沙门氏菌参考序列同源性达99%以上。分离菌株接种小白鼠,证明其对小白鼠有致病性。用沙门氏菌属标准血清检测证实其抗原式为6,7∶c∶1,5,符合猪霍乱沙门氏菌的抗原特征。应用以上方法从全国各地病料中分离鉴定了40多株猪霍乱沙门氏菌,为猪霍乱沙门氏菌病的流行病学调查提供了依据,同时证明该方法切实可行。

Salmonella choleraesuis （ S. choleraesuis） is the main pathogen of piglet paratyphoid, causing severe harm to pig industry. To establish a rapid isolation and identification procedure is of significance in S. eholeraesuis epidemiological investigation. The feces was collected from diseased piglets clinically diagnosed as paratyphoid, inoculated on Sodium Selenite brilliant green SS medium, then streaked on SS medium. The colorless and transparent colonies were purified and Gram-stained. The purified strain was identified to be S. Choleraesuis with GN2 microplate of American BIOLOG automated identification system, as well as the routine biochemical tubes. The gene invA was amplified with PCR and sequenced. There was over 99% homology at nucleotide level between published sequence of S. eholeraesuis and this isolate. The isolate was virulent to mice and the serotype was confirmed to be 6, 7 ： c： 1, 5, typical antigen pattern of S. choleraesuis. More than 40 S. eholeraesuis strains were isolated from the diseased piglets, indicating that the above procedure was practical and the data could be contributed to understand the epidemiology of S. eholeraesuis infection in China.