一例猪瘟病毒与大肠杆菌混合感染的实验室诊断

肇东市某商品猪场内仔猪大批发病,病猪精神状态极差、发热、食欲下降、拉白色糊状并伴有腥臭味的粪便,有些迅速死亡但死亡率不高。为确诊此批病猪,运用临床分子生物学诊断和病理解剖观察等手段初步判定为大肠杆菌与猪瘟病毒混合感染。根据其剖解现象使用细菌学检测和PCR技术对蓝耳病病毒、猪圆环病毒、猪瘟病毒、大肠杆菌、放线杆菌及链球菌进行检测。SS培养基培养出的菌落形态为圆形半透明的小凸起,革兰氏染色镜检后观察到是革兰氏阴性杆菌。PCR检测结果显示猪瘟病毒为阳性。最终确诊为大肠杆菌和猪瘟病毒混合感染。通过对分离细菌进行药敏试验结果显示该菌对环丙沙、硫酸阿米卡星、恩诺沙星、阿莫西林等药物较为敏感。

Laboratory diagnosis of a mixed infection of Escherichia coli with Swine fever virus

A large number of piglets in a commercial pig farm in Zhaodong city came on sick. The sick pigs suffered from poor mental state, fever, decreased appetite, white paste and smelly feces. Some of them died quickly but the death rate was not high. In order to confirm the diagnosis of this batch of sick pigs, we used clinical molecular biological diagnosis and pathological anatomical observation and other means to preliminarily determine the mixed infection of escherichia coli and swine fever virus. Bacteriological test and PCR were used to detect blue-ear disease virus, porcine circovirus, swine fever virus, escherichia coli, actinobacter spp. and streptococcus. The colonies cultured in SS medium were round and translucent bulges, which were observed to be gram-negative bacilli by gram staining microscopy. The PCR results showed that CSFV was positive. The final diagnosis was a mixed infection of e. coli and swine fever virus. The results showed that the bacteria were sensitive to ciprofloxacin, amikacin sulfate, enoxacin and amoxicillin.