Department of Veterinary Medicine, University of Bari, Valenzano 70010, Italy.
Faculty of Veterinary Medicine, University of Teramo, Teramo 64100, Italy.
J Vet Sci. 2021 Nov;22(6):e84. doi: 10.4142/jvs.2021.22.e84.
Enteritis of an infectious origin is a major cause of productivity and economic losses to cattle producers worldwide. Several pathogens are believed to cause or contribute to the development of calf diarrhea. Astroviruses (AstVs) are neglected enteric pathogens in ruminants, but they have recently gained attention because of their possible association with encephalitis in humans and various animal species, including cattle.
This paper describes a large outbreak of neonatal diarrhea in buffalo calves (), characterized by high mortality, which was associated with an AstV infection.
Following an enteritis outbreak characterized by high morbidity (100%) and mortality (46.2%) in a herd of Mediterranean buffaloes () in Italy, 16 samples from buffalo calves were tested with the molecular tools for common and uncommon enteric pathogens, including AstV, kobuvirus, and torovirus.
The samples tested negative for common enteric viral agents, including Rotavirus A, coronavirus, calicivirus, pestivirus, kobuvirus, and torovirus, while they tested positive for AstV. Overall, 62.5% (10/16) of the samples were positive in a single round reverse transcription polymerase chain reaction (PCR) assay for AstV, and 100% (16/16) were positive when nested PCR was performed. The strains identified in the outbreak showed a clonal origin and shared the closest genetic relationship with bovine AstVs (up to 85% amino acid identity in the capsid).
This report indicates that AstVs should be included in a differential diagnosis of infectious diarrhea in buffalo calves.
感染性肠炎是全球牛养殖者造成生产力和经济损失的主要原因。有几种病原体被认为会导致或促成犊牛腹泻的发展。星形病毒（AstVs）是反刍动物中被忽视的肠道病原体，但由于它们可能与人脑炎以及包括牛在内的各种动物物种的脑炎有关，最近引起了关注。
本文描述了一种以高死亡率为特征的水牛新生腹泻的大规模暴发，该暴发与 AstV 感染有关。
在意大利的一个地中海水牛群中发生了一种肠炎暴发，其特征是高发病率（100%）和死亡率（46.2%），对 16 头水牛犊的样本进行了常见和罕见肠道病原体的分子检测，包括 AstV、Kobuvirus 和 Torovirus。
测试样本对常见肠道病毒病原体（包括轮状病毒 A、冠状病毒、杯状病毒、瘟病毒、Kobuvirus 和 Torovirus）均呈阴性，但对 AstV 呈阳性。总体而言，16 份样本中有 62.5%（10/16）在单次反转录聚合酶链反应（PCR）检测中对 AstV 呈阳性，而在巢式 PCR 检测中 100%（16/16）呈阳性。在暴发中鉴定出的菌株具有克隆起源，与牛源 AstVs 具有最密切的遗传关系（衣壳蛋白的氨基酸同一性高达 85%）。
本报告表明，在对水牛犊的传染性腹泻进行鉴别诊断时，应将 AstVs 纳入其中。
