Whole-genome characterization and zoonotic insights of feline rotavirus A genotypes G3P[9] and novel G6P[9] circulating in domestic cats in Thailand

TL;DR

This study identifies new rotavirus strains in cats in Thailand and suggests they could potentially spread to humans.

Contribution

First detection of novel feline rotavirus genotype G6P[9] in Thailand and evidence of potential zoonotic transmission.

Findings

Three FeRVA strains identified: one G3P[9] and two novel G6P[9] genotypes.

G6P[9] strains showed genetic similarity to human and feline RVA strains in Japan.

Most infected cats were asymptomatic, with no significant clinical associations.

Abstract

Rotavirus A (RVA) is an enteric pathogen affecting both humans and animals, known for its zoonotic potential. Feline RVA (FeRVA) infections are increasingly reported worldwide; however, data remain limited in Thailand. This study aimed to determine the prevalence, genotype distribution, and whole-genome features of FeRVA found in domestic cats in Thailand, as well as to assess the potential for cross-species transmission.

A cross-sectional survey was conducted from January 2022 to December 2023 in Bangkok and nearby provinces. Rectal swab samples (n = 636) were collected from both symptomatic and asymptomatic cats and screened for RVA using reverse-transcription polymerase chain reaction (RT-PCR) targeting the nonstructural protein 5 (NSP5) gene. Samples positive for FeRVA were subjected to whole-genome sequencing (WGS) using Oxford Nanopore technology. Genotypes were assigned based on all 11 gene segments, and phylogenetic analyses were performed using the neighbor-joining method to compare Thai strains with global RVA reference strains.

The FeRVA positivity rate was 1.41% (9/636). Three FeRVA-positive samples were successfully sequenced. Whole-genome analysis identified one strain as genotype G3P[9] and two strains as genotype G6P[9]. The G6P[9] strains showed the genetic constellation G6-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3, identical to feline and human RVA G6P[9] strains previously reported in Japan. The G3P[9] strain displayed high nucleotide identity with Thai and East Asian human RVAs. Most FeRVA-positive cats were asymptomatic, and no significant association was found between infection status and age, season, or clinical signs. Analysis of the viral protein 7 antigenic regions revealed conserved amino acids, apart from a single substitution (S90P) in G6P[9].

This study reports the first detection of the novel FeRVA genotype G6P[9] in Thailand and provides comprehensive genomic evidence of FeRVA diversity in domestic cats. The close genetic relationship between Thai-FeRVA strains and human RVA strains highlights the potential for interspecies transmission. Enhanced surveillance and One Health–based monitoring are recommended to improve early detection and prevent zoonotic spread.

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