Successful in vitro propagation of feline coronavirus from clinically diagnosed feline infectious peritonitis cases using Vero cells: A potential model for future research

Eaftekhar Ahmed Rana; Mahfuza Akther; Susan Beetson; Subir Sarker; Gabriele Rossi; Jasim M Uddin

doi:10.1002/vro2.70030

Successful in vitro propagation of feline coronavirus from clinically diagnosed feline infectious peritonitis cases using Vero cells: A potential model for future research

Vet Rec Open. 2026 Feb 25;13(1):e70030. doi: 10.1002/vro2.70030. eCollection 2026 Jun.

Authors

Eaftekhar Ahmed Rana^{1

2}, Mahfuza Akther¹, Susan Beetson¹, Subir Sarker³, Gabriele Rossi¹, Jasim M Uddin^{1

4

5}

Affiliations

¹ School of Veterinary Medicine Murdoch University Perth, West Australia Australia.
² Department of Microbiology and Veterinary Public Health Chattogram Veterinary and Animal Sciences University Chattogram Bangladesh.
³ Biomedical Sciences & Molecular Biology, College of Medicine and Dentistry James Cook University Townsville Queensland Australia.
⁴ Centre for Animal Production and Health Food Futures Institute Murdoch University Murdoch, West Australia Australia.
⁵ Centre for Biosecurity and One Health Harry Butler Institute Murdoch University Perth, West Australia Australia.

Abstract

Background: Feline coronavirus (FCoV) causes inapparent to progressive fatal feline infectious peritonitis (FIP) in domestic and wild cats, which affects multiple-organ systems.

Methods: We investigated three clinically sick cats using different laboratory and molecular tests to diagnose and confirm FCoV and propagate the virus in Vero cell culture.

Results: All the cats exhibited effusive FIP with multiple clinical signs. The haematology profiles revealed lymphopenia in all cases and leukopenia, neutropenia and regenerative left shift in one case. Serum biochemistry showed elevated creatine kinase, aspartate aminotransferase, hyperbilirubinaemia and hypoalbuminaemia in all the cases. Urinalysis revealed bilirubinuria in two cases and marked proteinuria in another. All effused samples showed a positive Rivalta test, and the cytology showed a mixed pyogranulomatous inflammatory exudate. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) confirmed that all the cats were infected with FCoV. The specific gene sequencing of three isolates clustered in the same clade of the phylogenetic tree, suggesting a closely related genotype associated with FIP in cats. Feline coronavirus induced cytopathic effects (CPEs) in Vero cells, first appearing on day 5 post-infection (pi) in the primary passage. In the second passage, more distinct CPEs, including cell rounding, shrinkage, detachment and death, were evident from day 2 pi. Reverse transcription quantitative polymerase chain reaction confirmed active viral replication, with significantly decreasing Ct values across passages.

Conclusions and clinical importance: The adaptation and propagation of FCoV in a non-feline cell line provide promising opportunities for future studies, including generating sufficient viral RNA for sequencing, evaluating antiviral resistance, and establishing a practical in vitro system for drug screening and vaccine development.

Keywords: FCoV; RT‐qPCR; Vero cell culture; cats; cytopathic effect; laboratory diagnosis; phylogenetic analysis.