一起麻鸡鸡痘病毒与巴氏杆菌混合感染病例的诊断

Diagnosis of fowlpox virus and Pasteurella co-infection in Ma chicken

为了对2011年10月长春市某鸡场的150多只60日龄麻鸡发生急性死亡,病死鸡在临床上出现食欲不振、精神委靡,鸡冠以及背部皮肤有结节状痘疹以及排黄绿色稀粪等临床症状的疾病进行确诊,通过细菌学检查、病毒分离鉴定、动物回归试验以及病理组织学观察等方法从病原学和病理学角度进行了系统的分析。病死鸡肝触片可见有典型的两极浓染的短杆菌;应用鸡痘病毒4b核心蛋白基因特异性引物的扩增结果为阳性;将痘疹病料处理上清液经尿囊绒毛膜途径接种9日龄SPF鸡胚,接种后第7天可见尿囊膜上形成有灰白色突起的痘斑;皮肤痘疹研磨处理上清液经电镜负染观察可见典型的痘病毒粒子。病理组织学观察结果表明,局部肝细胞发生变性、坏死,并伴有多量的异嗜性粒细胞浸润。根据上述实验室检测结果并结合临床症状进行综合分析,确诊该起病例为鸡痘病毒与巴氏杆菌混合感染所致。

In October 2011 ,more than 150 Ma chickens with only 60 day-old were dead because of the outbreak of an acute deaths in Changchun. The chickens were loss of appetite,apathetic and steak yellow green thin stool. A large of pox eruptions having different sizes and nodular lesions were observed in the skins of crista galli and the smoothness and few feather of the back. In order to diagnose the disease,a sys- tematic analysis of the etiology and pathology was conducted by bacteriology, virus isolation and identifica- tion, animal regression test, and histopathological observation. A typical bipolar stain brevibacterium can be seen in the liver contacts of dead birds. PCR detection results showed that the fowlpox virus 4b core protein gene with specific primers amplified was positive. The processing supernatant of pox eruptions was inocula- ted on the surface of chorioallantoic membrane of SPF embryonated egg in 9-day-old. After 7 days,grayish- white variola were observed on the surface of chorioallantoic membrane. Also typical poxvirus particles could be seen under electron microscopy of negatively stained. The histopathological results showed that partial liver cell suffered from congestion, degeneration, necrosis, and a large number of heterophil granulo- cyte infiltration. It was confirmed that the cases were caused by fowlpox virus and Pasteurella mixed infec- tion according to the above-mentioned laboratory test results and clinical symptoms.