鸭疫里默氏杆菌与鸭源呼肠孤病毒混合感染的病理学诊断

Pathological diagnosis of mixed infection of Riemerella anatipestis with duck reovirus

为确诊湖北省某鸭场自然发病的13日龄雏蛋鸭的死亡原因,对送检的7只病鸭进行了临床症状观察、病理剖检、细菌分离鉴定、病毒PCR/RT-PCR检测和组织病理学分析。结果显示,病鸭临床症状为头肿大流泪,脚软,共济失调,排白色稀便。病理剖检观察到病鸭有严重的全身浆膜纤维素性渗出和脾坏死,法氏囊、胸腺萎缩;分离细菌的培养鉴定结果为革兰阴性短杆菌,16S rRNA测序结果鉴定该分离菌株为鸭疫里默氏杆菌,药敏试验得出该分离菌对头孢类和阿莫西林等敏感;通过病毒特异性引物扩增出鸭呼肠孤病毒条带;组织病理学观察见纤维素性心包炎、肝周炎、气囊炎、脑膜炎,脾坏死,胸腺和法氏囊淋巴细胞减少。综合以上研究结果,表明该批鸭是由鸭疫里默氏杆菌与鸭源呼肠孤病毒混合感染而导致大量发病死亡的。

To confirm the cause of death of 13-day-old ducklings naturally infected on a duck farm in Hubei Province,clinical symptoms,pathological examination,bacterial isolation and identification,virus PCR/RT-PCR detection and histopathological analysis were carried out on 7 sick ducks.In result,the clinical symptoms of diseased ducks were enlarged head,tears,soft feet,ataxia and white stool discharge.Severe systemic serous cellulosic exudation and splenic necrosis,bursa of fabricius and thymus atrophy were observed in diseased ducks by pathological examination The culture identification of the isolated bacteria was gram-negative brevibacterium,and the 16 S r RNA sequencing result identified the isolated strain as Riemerella anatipestis.Drug susceptibility test showed that the isolate was sensitive to cephalosporins and amoxicillin.Amplification of duck reovirus bands by virus-specific primers.Histopathological observation showed cellulosic pericarditis,perihepatitis,air sac inflammation,meningitis,splenic necrosis,thymus and bursa of fabricius lymphocyte decreased.The above-mentioned results showed that the ducks were infected by Riemerella anatipestis and duckorigin reovirus,which resulted in a large number of morbidity and death.