肉鸡禽呼肠孤病毒与巴氏杆菌混合感染的鉴别诊断

Differential Diagnosis of Avian Reovirus and Pasteurella Mixed Infection in Broiler

2014年11月河北某规模化鸡场一批4周龄左右的肉鸡发病死亡,临床表现为精神沉郁、呼吸困难、关节肿大、跛行等症状,为对此疫病进行确诊,通过病理组织学观察、细菌分离、PCR检测、药敏试验、动物致病性试验等实验室诊断方法进行系统分析。病理组织学观察结果显示肺脏出血,心脏、肝脏水肿,并伴有异嗜性粒细胞浸润;镜检可见两极深染的短杆菌;用多杀性巴氏杆菌KMT-1基因和禽呼肠孤病毒(ARV)σB基因特异性引物的扩增结果均为阳性;该巴氏杆菌分离菌可致死小鼠,且对头孢曲松、头孢哌酮等药物高度敏感。根据上述实验室检测结果并结合临床症状进行综合分析,最终确诊该病为ARV和巴氏杆菌混合感染。

In December 2014,agroup of 4weeks old broilers died in a large-scale chicken farm in Hebei province.The clinical symptoms of the ill and diseased chicken were depression,dyspnea,joint swelling and claudication.In order to diagnose the disease,a systematic analysis was conducted by laboratory diagnostic methods that included histopathological observation,bacterial isolation,PCR detection,drug sensitive test and animal pathogenicity experiment.The histopathological observation results showed that hemorrhage in the lung,the edema of heart and liver,a large number of heterophil granulocyte infiltration.Bipolar stained brevibacterium was observed under the microscopy.The PCR amplification results of Pasteurella multocida KMT-1gene and avian reovirusσBgene were positive by using specific primers.The isolated Pasteurellacould be lethal to mice and the isolate was highly sensitive to ceftriaxone and cefoperazone.Combination with the above laboratory test results and the clinical symptoms,we confirmed that the cases were mixed infection of avian reovirus and Pasteurella.