Jianbao Dong1,2,3, Guiqin Liu2, Nannan Gao3, Jiajia Suo1, Jelle Matthijnssens4, Shuguang Li5, Dongfang Yuan1, Yan Du1, Jun Zhang3, Nanako Yamashita6, Takeshi Haga6, Frank R Cook7, Wei Zhu1,3. 1. Department of Veterinary Medical Science, Shandong Vocational Animal Science and Veterinary College, Weifang, China. 2. Research Institute of Effective-Breeding and Eco-Feeding of Donkey, College of Agronomy, Liaocheng University, Liaocheng, China. 3. Academy of Animal Science and Veterinary Medicine, Qinghai University, Xining, China. 4. Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical and Epidemiological Virology, Rega Institute, University of Leuven, Leuven, Belgium. 5. Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou, China. 6. Division of Infection Control and Disease Prevention, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan. 7. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, USA.
Abstract
BACKGROUND: In contrast to horses, the only evidence suggesting gastrointestinal disease in neonatal donkeys is associated with Group A rotaviruses (RVAs) is the detection of viral antigens by ELISA in just 1 of 82 symptomatic donkey foals. No additional, more comprehensive investigations have been conducted, and RVAs if circulating in donkey populations have not been molecularly characterised. OBJECTIVES: To investigate if RVAs are associated with an outbreak of severe enteritis in neonatal donkeys and if associated determine the genotype(s) along with the phylogenetic relationship to RVA strains circulating in horses. STUDY DESIGN: Cross-sectional. METHODS: RT-PCR-based techniques were used for RVA diagnosis and gene amplification. Statistical significance was determined by Chi-square and Fisher's exact two-sided tests. Genotyping was performed by RotaC and phylogenetic analysis by neighbour joining. RESULTS: In 2019, acute enteritis occurred in 119 of 206 donkey foals (≤4 months) at two intensive donkey farms in the Shandong province of China. The highest morbidity (68.1%), mortality (29.5%) and fatality levels (45.5%) occurred in foals in the 30-89 day, 30-59 day and 0-29 day age groups respectively. RVA gene sequences were detected in 107 (89.9%) of the symptomatic individuals while further analysis demonstrated the outbreak was associated with the same G3P[12] RVA strain designated RVA/Donkey-wt/CHN/Don01/2019/G3P[12]. Although the VP4 gene of Don01 exhibited close phylogenetic relationships with equivalent RVA sequences commonly circulating in horses, encoding VP7 was more closely associated with sequences isolated from bats suggesting this new donkey strain arose via an intergenogroup reassortment event. MAIN LIMITATIONS: Actual prevalence not determined because <7% of asymptomatic donkey foals were included in this study. The complete genomic sequence of RVA/Donkey-wt/CHN/Don01/2019/G3P[12] remains to be determined. CONCLUSIONS: Valuable new information about the molecular epidemiology of rotaviruses in different equid species is provided by isolation and molecular characterisation of a novel RVA strain from neonatal donkeys.
BACKGROUND: In contrast to horses, the only evidence suggesting gastrointestinal disease in neonatal donkeys is associated with Group A rotaviruses (RVAs) is the detection of viral antigens by ELISA in just 1 of 82 symptomatic donkey foals. No additional, more comprehensive investigations have been conducted, and RVAs if circulating in donkey populations have not been molecularly characterised. OBJECTIVES: To investigate if RVAs are associated with an outbreak of severe enteritis in neonatal donkeys and if associated determine the genotype(s) along with the phylogenetic relationship to RVA strains circulating in horses. STUDY DESIGN: Cross-sectional. METHODS: RT-PCR-based techniques were used for RVA diagnosis and gene amplification. Statistical significance was determined by Chi-square and Fisher's exact two-sided tests. Genotyping was performed by RotaC and phylogenetic analysis by neighbour joining. RESULTS: In 2019, acute enteritis occurred in 119 of 206 donkey foals (≤4 months) at two intensive donkey farms in the Shandong province of China. The highest morbidity (68.1%), mortality (29.5%) and fatality levels (45.5%) occurred in foals in the 30-89 day, 30-59 day and 0-29 day age groups respectively. RVA gene sequences were detected in 107 (89.9%) of the symptomatic individuals while further analysis demonstrated the outbreak was associated with the same G3P[12] RVA strain designated RVA/Donkey-wt/CHN/Don01/2019/G3P[12]. Although the VP4 gene of Don01 exhibited close phylogenetic relationships with equivalent RVA sequences commonly circulating in horses, encoding VP7 was more closely associated with sequences isolated from bats suggesting this new donkey strain arose via an intergenogroup reassortment event. MAIN LIMITATIONS: Actual prevalence not determined because <7% of asymptomatic donkey foals were included in this study. The complete genomic sequence of RVA/Donkey-wt/CHN/Don01/2019/G3P[12] remains to be determined. CONCLUSIONS: Valuable new information about the molecular epidemiology of rotaviruses in different equid species is provided by isolation and molecular characterisation of a novel RVA strain from neonatal donkeys.