Figure Legend
Figure 1 . The process of BHK-21 cell CPEs induced by SVV-CH-09-2018 infecting cells (A) One-step growth curve of SVV-CH-09-2018.on BHK-21 cells with the multiplicity of infection (MOI) of 0.1 and 0.5 (B). An electron microscope image of the SVV virus(C)
Figure 2. The evolutionary trees are drawn by Mega 7.0 and Omicstudio, the analysis data were obtained from NCBI database with the whole genome of reference SVV strains. In the final evolutionary tree, the experimental virus strain SVV-CH has been marked (▲), and the strains from different countries are also marked with different colors (A). Genome structure of type the Seneca virus, showing the plane structure of virions. It is composed of a 5 ’-terminal non-coding region (5’ UTR), a 3 ’-terminal non-coding region (3’ UTR) encoding a polyprotein, and only one open reading frame (ORF) (B).
Figure 3. The pathology and immunofluorescence indicated the pathological changes and the quality of virus virion. The pathological changes of duodenum and colon after the SVV infection (A). Viral antigens were detected mainly in villous epithelial cells of the colon. and the titer of the colon was much higher than that of the duodenum (B). In the mink challenge experiment, at 0, 7, 14, 21 and 28 days after challenge, mink sera were collected to determine the level of anti-SVA neutralizing antibody (C).
Figure 4. To indicate the adaptation and transmission of SVV. An adaptation from pig SVV to human SVV includes two circulations, the food chain circulation and the reservoir circulation. In the reservoir and food chain circulation, SVV are transmitting, mutating, and adapting between mice and minks (as well as other semiaquatic mammals). Mink and mice can be infected through contacting with epidemic water. In a free stall barn system, usually in some areas of developing countries, pig will inevitably lead to a land habitat circulation including human beings. The blue pathway is transmitted by fecal route, while the red one is transmitted by oral route. In rural areas of South Asia, Southeast Asia, Southern and Eastern China, pigs mink and mice, in particular chick are often observed to eat by human. The pigs and mink also have the opportunity to eat mice feces, but mice seldom eat pig feces.