Genomic Characterization of Two Bovine Enterovirus Strains Isolated from Newly Transported Cattle

This study isolated and identified two novel Chinese bovine enterovirus (BEV) strains, designated as BEV-GX1901 and BEV-GX1902, from newly transported cattle with the diarrheal feces symptom. We also determined their complete genome sequences (7408 and 7405 nucleotides, respectively) and found both strains have a genome organization analogous to that of picornaviruses. To better understand these two novel strains, a detailed analysis was applied to both strains, including the time of the cytopathic effect (CPE) production, TCID₅₀ measurement, trypsin sensitivity test, ether sensitivity test, chioroform sensitivity test, acid and alkali resistance test, and heat resistance test. Our results showed that these two strains are different in physical and chemical properties. Our study also characterized that BEV-GX1901 and BEV-GX1902, both belonging to the BEV-E4 subtype, were closely related to the Australian strains K2577 and SL305, and the Japanese strain IS1 based on their genome sequences and VP1 region characterizations. It is speculated that this may be related to cattle trade and transportation. Additionally, the gene-by-gene or amino acid-by-amino acid comparison of the two strains found they have differences between their 5'UTR, 3'UTR, VP2, VP1, 2A, 3C, and 3D regions. Our results provide an important update of the virus's presence in China and contribute to a better understanding of the distribution and characterization of BEVs in cattle.