Isolation and Pathogenic Analysis of a Highly Virulent Getah Virus Strain from Henan Province, China

Notably, high viral loads were detected in multiple organs (heart, liver, spleen, lung, kidney, brain, intestine, and lymph nodes)，with peak levels reaching up to 8.93 lg copies/mL (jejunum). Compared with the control group, the infected piglets showed significant impairment of intestinal barrier function and enhanced inflammatory responses. This was evidenced by the downregulated mRNA expression of barrier-related genes (ZO-1 and Occludin) and mucus components (CLCA1, Zg16, and MUC2), the upregulated expression of inflammatory cytokines (IL-6, IL-8, and TNF-α), and increased serum levels of intestinal permeability markers (DAO and D-Lac).

Further analysis of the gut microbiota revealed that GETV infection altered the diversity and composition of the cecal microbial community in piglets from the phylum to genus level, which was characterized by a reduction in the abundance of beneficial bacteria (Lactobacillus, Faecalibacterium, Blautia) and an increase in conditional pathogenic bacteria (Escherichia-Shigella, Porphyromonas, Akkermansia). In conclusion, these results contribute to a deeper understanding of GETV pathogenesis and lay the groundwork for developing effective biologics for its control.