The Prevalence, genetic diversity and evolutionary analysis of Cachavirus firstly detected in northeastern China

Abstract

Canine Cachavirus was novel parvovirus species which has been firstly detected in dogs in the USA, belonging to the Chaphamaparvovirus genus. However, the prevalence and genetic characteristics of Cachavirus are relatively limited. In this study, 325 canine fecal specimens collected from healthy and diarrheic dogs in northeastern China were screened. A total of 22 out of 325 (6.8%) samples were positive for Cachavirus by PCR. Diarrhea samples showed high viral co-infection rates, and we detected co-infection of canine astrovirus (CaAstV) and Cachavirus for the first time. Moreover, sequence analysis revealed that the Chinese Cachavirus strain has a point mutation at four consecutive amino acid sites compared to the original American strain. And we determined the codon usage bias of the VP1 gene. Codon usage analysis showed that most preferred codons in Cachavirus were A- or T-ended codons, similar to traditional canine parvovirus. Co-evolutionary analysis showed that Cachavirus was likely the result of co-evolution with Feline chaphamaparvovirus. Our findings provide information on the expansion of the limited Cachavirus sequences, point to more details about the molecular characterization of the strains in northeastern China. Further epidemiological surveillance is necessary to determine the significance and evolution of Cachavirus.