关键词: 猫；杯状病毒；分离鉴定；遗传进化

Abstract: To investigate the genetic variation of prevalent feline calicivirus（FCV）strains circulating in China， ocular and nasal swabs were collected from cats with suspected FCV infection in Henan and Tianjin provinces/ municipalities for virus isolation. The isolated strains were subjected to purity，specificity，viral load and VP1 gene sequencing. The results showed that all 15 FCV isolates exhibited satisfactory purity and specificity，with viral loads no lower than 107.5TCID50/mL. Sequence analysis of the VP1 gene revealed that the nucleotide homology of the VP1 gene among the 15 FCV strains ranged from 72.8% to 99.9%，and the nucleotide homology of those strains with 18 published domestic and foreign FCV reference strains retrieved from GenBank ranges from 73.0% to 87.1%。Based on genetic differences in the sequences，these strains were classified into two genotypes，GⅠ and GⅡ，including 13 GⅠstrains（accounting for 86.7%）and 2 GⅡ strains（accounting for 13.3%）. In addition，all isolated strains displayed substantial genetic divergence from three classic GⅠvaccine reference strains. The above findings provide fundamental data for further elucidating the genetic variation of prevailing FCV strains in China and optimizing vaccine selection strategies.

Key words: Feline；Calicivirus；Isolation and identification；Phylogenetic