Rosenberger J K, Sterner F J, Botts S, Lee K P, Margolin A
Department of Animal Science and Agricultural Biochemistry, College of Agricultural Sciences, University of Delaware, Newark 19717-1303.
Avian Dis. 1989 Jul-Sep;33(3):535-44.
Pathogenicity, pathogenesis, and antigenic relatedness of four avian reovirus isolates obtained from commercially reared broilers were investigated. Chickens of various ages were inoculated both orally and intratracheally with reovirus. Based on disease signs, mortality, weight depression, tissue lesions, invasiveness, and viral persistence in chickens inoculated at 1 day of age, the isolates were classified as being of low, intermediate, or high pathogenicity. The low-pathogenicity isolate (2177) did not cause mortality, weight depression, or clinical disease. The isolate of intermediate pathogenicity (2035) produced low mortality rates (8%), some weight reduction by 7 weeks postinoculation, and microscopic lesions in the intestine and gastrocnemius tendons. The pathogenic isolates, 2408 and 1733, caused severe clinical disease characterized by stunting, feathering abnormalities, mortality as high as 84%, and microscopic lesions in the liver, intestine, pancreas, and/or gastrocnemius tendon. Highly pathogenic isolates also persisted longer in tissues of infected birds and elicited a more prompt and prolonged antibody response. Birds inoculated at 1 day or 1 week of age were more susceptible to reovirus-induced disease than birds inoculated at 2 weeks, suggesting an age-associated resistance. All isolates produced mortality with equal frequency in embryos. The isolates characterized were found to be antigenically similar based on cross-neutralization and cross-protection studies.
对从商业饲养的肉鸡中获得的4株禽呼肠孤病毒分离株的致病性、发病机制及抗原相关性进行了研究。给不同年龄的鸡经口和气管内接种呼肠孤病毒。根据1日龄接种鸡的疾病症状、死亡率、体重减轻、组织病变、侵袭性及病毒持续性，将分离株分为低致病性、中等致病性或高致病性。低致病性分离株（2177）未引起死亡、体重减轻或临床疾病。中等致病性分离株（2035）导致低死亡率（8%），接种后7周体重有所减轻，且在肠道和腓肠肌腱出现微观病变。致病性分离株2408和1733引起严重临床疾病，特征为发育迟缓、羽毛异常、死亡率高达84%，且在肝脏、肠道、胰腺和/或腓肠肌腱出现微观病变。高致病性分离株在感染禽组织中持续存在的时间也更长，并引发更迅速和持久的抗体反应。1日龄或1周龄接种的鸡比2周龄接种的鸡对呼肠孤病毒诱导的疾病更易感，提示存在年龄相关的抵抗力。所有分离株在胚胎中导致死亡的频率相同。基于交叉中和及交叉保护研究发现，所鉴定的分离株在抗原性上相似。
