Rotavirus C (RVC) has been detected increasingly in humans and swine in different countries, including the US. It is associated with significant economic losses due to diarrheal disease in nursing piglets. In this study we aimed: (1) to determine the prevalence of RVC in healthy and diarrheic suckling piglets on US farms; and (2) to evaluate if maternal antibody (Ab) levels were associated with protection of newborn suckling piglets against RVC. There was a significantly higher prevalence (p = 0.0002) of litters with diarrhea born to gilts compared with those born to multiparous sows. Of 113 nursing piglet fecal samples tested, 76.1% were RVC RNA positive. Fecal RVC RNA was detected in significantly (p = 0.0419) higher quantities and more frequently in piglets with diarrhea compared with healthy ones (82.5 vs. 69.9%). With the exception of the historic strain Cowden (G1 genotype), field RVC strains do not replicate in cell culture, which is a major impediment for studying RVC pathogenesis and immunity. To circumvent this, we generated RVC virus-like particles (VLPs) for Cowden (G1), RV0104 (G3) and RV0143 (G6) and used them as antigens in ELISA to detect swine RVC Abs in serum and milk from the sows. Using RVC-VLP Ab ELISA we demonstrated that sows with diarrheic litters had significantly lower RVC IgA and IgG Ab titers in milk compared to those with healthy litters. Thus, our data suggest that insufficient lactogenic protection provided by gilts plays a key role in the development of and the increased prevalence of clinical RVC disease.

中文翻译：

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轮状病毒 C：哺乳仔猪中的患病率和病毒样颗粒的形成，以评估母体免疫力对疾病发展的影响。

在包括美国在内的不同国家，人类和猪中越来越多地检测到轮状病毒 C (RVC)。它与哺乳仔猪腹泻病造成的重大经济损失有关。在本研究中，我们的目的是：(1) 确定美国农场健康和腹泻哺乳仔猪中 RVC 的患病率；(2) 评估母源抗体 (Ab) 水平是否与保护新生哺乳仔猪免受 RVC 相关。与经产母猪所生的仔猪相比，后备母猪所生仔猪腹泻的患病率显着较高（p = 0.0002）。在检测的 113 份哺乳仔猪粪便样本中，76.1% 为 RVC RNA 阳性。与健康仔猪相比，腹泻仔猪粪便中 RVC RNA 的检测量显着更高（p = 0.0419），且频率更高（82.5% vs. 69.9%）。除历史菌株 Cowden（G1 基因型）外，野外 RVC 菌株在细胞培养中不复制，这是研究 RVC 发病机制和免疫的主要障碍。为了避免这个问题，我们为 Cowden (G1)、RV0104 (G3) 和 RV0143 (G6) 生成了 RVC 病毒样颗粒 (VLP)，并将它们用作 ELISA 中的抗原来检测母猪血清和牛奶中的猪 RVC 抗体。使用 RVC-VLP Ab ELISA，我们证明，与健康仔猪相比，腹泻仔猪的牛奶中 RVC IgA 和 IgG Ab 滴度显着降低。因此，我们的数据表明，后备母猪提供的泌乳保护不足在临床 RVC 疾病的发生和患病率增加中发挥着关键作用。