Isolation, Identification, and Genetic Evolution Analysis ofGene of Feline Calicivirus Strain ZZ202306.

Abstract

This study investigated a suspected Feline calicivirus (FCV) outbreak at a veterinary facility in Zhengzhou, Henan Province, China. RT-PCR analysis confirmed the FCV presence, with subsequent CRFK cell culture propagation leading to the isolation and characterization of strain ZZ202306. Immunofluorescence and Western blot analyses validated the specificity of monoclonal antibodies targeting the FCV VP1 capsid protein. Transmission electron microscopy revealed non-enveloped virions of ~40 nm in diameter, exhibiting typical caliciviral architecture. Viral replication kinetics demonstrated exponential growth between 6 and 18 h post-inoculation, reaching a peak titer of 10TCID/0.1 mL. Genomic sequencing coupled with phylogenetic reconstruction of thegene revealed a close genetic relation to domestic Chinese strains and international variants, while maintaining distinct evolutionary divergence from other calicivirus genera.