Epidemiological and evolutionary analysis of canine circovirus from 1996 to 2023.

BACKGROUND: Canine circovirus (CanineCV), a non-enveloped virus with a circular DNA genome, has been identified in various avian and mammalian species, including domestic and wild canids. This study aimed to comprehensively analyze the prevalence of CanineCV across diverse animal species in 11 provinces of China. RESULTS: A total of 1,666 serum samples were collected, revealing a 5.82% prevalence of CanineCV in dogs, with the highest rates being observed in southern and eastern China. Phylogenetic analysis of 266 global CanineCV genomes sourced from the NCBI identified six distinct genotypes, elucidating the complex dynamics of their evolution. Evidence suggested a potential bat origin for CanineCV, with positive selection and high rates of evolution being observed. Recombination analysis revealed dynamic genetic exchange, highlighting the intricate nature of CanineCV evolution. Mutational analysis identified key amino acid substitutions likely to influence the virus's adaptation. Additionally, glycosylation, palmitoylation, and SUMOylation sites were predicted, shedding light on crucial functional properties of the virus. CONCLUSIONS: This study provides a global perspective on the origin, genetic diversity, and evolutionary dynamics of CanineCV. Understanding these factors is crucial for elucidating its epidemiology and potential health risks.

The detection of canine circovirus in Guangxi, China.

Since the first description of canine circovirus (CanineCV)-associated infection, there have been several reports on the distribution of the disease in worldwide. To investigate the prevalence and genetic diversity of CanineCV in China, we conducted PCR screening of 1226 dog serum samples collected from different regions in mainland China between 2014 and 2016. CanineCV DNA was found in 81/926 serum samples from Guangxi Province. Furthermore, 25 full-length genomes of CanineCV from positive samples were sequenced and compared with CanineCV sequences in the GenBank database. Pairwise analysis showed that the determined genome sequences shared 84.9%-100% identity among themselves and 81.4%-90.5% with the other 28 sequences. Phylogenetic analysis revealed that the 52 viral genome sequences could be divided into two genotypes (CanineCV-1 and CanineCV-2). Analysis of the amino acid sequences of the capsid protein revealed the existence of 9 major regions of variation. The present work contributes to the understanding of CanineCV molecular epidemiology.