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

## TL;DR

This study identifies and characterizes two new bovine enterovirus strains in China, offering insights into their genomic features and potential links to international cattle trade.

## Contribution

The first report of EV-E4 in transported cattle in China, with detailed genomic and physicochemical characterization.

## Key findings

- The two strains have complete genomes of 7408 and 7405 nucleotides with typical picornavirus organization.
- Phylogenetic analysis shows they are closely related to Australian and Japanese EV-E4 strains.
- Genomic variations were found in non-coding and structural protein regions, suggesting international transmission via cattle trade.

## Abstract

This study addresses the lack of genomic data on bovine enteroviruses (BEVs) in transported cattle, which pose potential risks for disease transmission in livestock trade. We isolated two EV-E4 strains (BEV-GX1901 and BEV-GX1902) from diarrheal feces of newly transported cattle in China, aiming to characterize their genomic features, physicochemical properties, and phylogenetic relationships. The complete genomes (7408 nt and 7405 nt, respectively) revealed a typical picornavirus organization, showing different physical and chemical properties. The phylogenetic analysis showed that two strains were similar to EV-E4 strains (Australian strains K2577, SL305, and Japanese strain IS1), sharing a 76.7–90.9% VP1 nucleotide identity, with notable genomic variations in non-coding regions and structural proteins. These findings represent the first report of EV-E4 in transported cattle in China, suggesting possible links to the international livestock trade. Our results provide important updates on the prevalence of this virus in China and enhance the understanding of the BEV distribution and characteristics in cattle populations. In addition, this study also provides a scientific basis for disease control policies in the global livestock trade.

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.