Abstract：
This study characterized the susceptibility and dynamic of porcine deltacoronavirus infection in grower pigs under experimental conditions using a combination of syndromic and laboratory assessments. Seven-week-old conventional pigs (n = 24) were randomly distributed into PDCoV- (n = 12) and mock-inoculated (n = 12) groups. Serum was collected at -7, 0, 3, 7, 10, 14, 17, 21, 28, 35, and 42 days post-inoculation (DPI) to evaluate viremia (RT-qPCR) and antibody response (S1-based ELISA). Viral shedding and potential infectivity were determined using pen-based oral fluids and feces collected every other day between DPI 0 and 42. Pigs showed no clinical signs or viremia throughout the study. Active virus shedding was detected in feces (6-22 DPI) and oral fluids (2-30 DPI), peaking at DPI 10. IgG was first detected at DPI 10, being statistically significant after DPI 14 and increasing thereafter, coinciding with the progressive resolution of the infection. Likewise, a significant increase in proinflammatory IL-12 was detected between DPI 10 and 21 in PDCoV-inoculated pigs, which could enhance innate resistance to PDCoV infection. This study demonstrated that active surveillance based on systematic sampling and laboratory testing combining molecular and serological tools is critical for the accurate detection of subclinical circulation of PDCoV in pigs after weaning.
摘要：
这项研究使用综合征和实验室评估相结合的方法，在实验条件下表征了生长猪中猪白角病毒感染的易感性和动态。将7周龄的常规猪(n=24)随机分成PDCoV-(n=12)和模拟接种(n=12)组。在接种后(DPI)-7、0、3、7、10、14、17、21、28、35和42天收集血清以评估病毒血症(RT-qPCR)和抗体应答(基于S1的ELISA)。使用基于笔的口腔液和在DPI0和42之间每隔一天收集的粪便来确定病毒脱落和潜在的感染性。在整个研究中,猪没有表现出临床体征或病毒血症。在粪便（6-22DPI）和口腔液（2-30DPI）中检测到活跃的病毒脱落，达到DPI10的峰值。首先在DPI10检测到IgG，在DPI14后具有统计学意义，此后增加，与感染的逐渐消退相吻合。同样，在接种PDCoV的猪中，在DPI10和21之间检测到促炎IL-12的显着增加，这可以增强对PDCoV感染的先天抵抗力。这项研究表明，基于系统采样和实验室测试结合分子和血清学工具的主动监测对于准确检测断奶后猪中PDCoV的亚临床循环至关重要。
