Genetic characterization of canine rotavirus isolated from a puppy in Korea and experimental reproduction of disease.

Abstract

Canine rotavirus was isolated from feces of a Korean Jindo dog with mild diarrhea, and the isolate was genetically characterized. Rotaviral antigen was detected in the feces using a commercial rotavirus antigen detection kit and cytopathic effects were observed in a cell line inoculated with the feces. The virus isolate (GC/KS05) was identified as subtype G3P[3] using reverse transcription polymerase chain reaction (RT-PCR). The strain displayed 98% and 90% identity with the VP7 genes of a canine rotavirus isolate (RV52/96) from Italy and the simian rotavirus strain (RRV) respectively. However, the GC/KS05 isolate exhibited only 83% and 82% identity, respectively, with the G3 serotype canine strains, RV198/95 and K9. Phylogenetic analysis of the VP7 and VP4 genes of GC/KS05 strain led to the classification of VP7 in a different cluster than other canine rotavirus VP7 genes, and VP4 within the cluster of canine rotavirus VP4 genes. The Korean isolate was thus more closely related to the RV52/96 isolate than the other isolates for which sequence data is available. Detailed analysis of the VP7 region revealed 6 amino acid variations between the new isolate and RV52/96. After 5 passages in cell culture, the GC/KS05 strain remained pathogenic for young pups, in which inoculation resulted in diarrhea and virus shedding in the feces.