Isolation of feline viral rhinotracheitis agent and its antigenic properties

Introduction. Viral respiratory diseases pose a serious problem for the health of cats all over the world. Feline herpesvirus type 1 (FHV-1) is the causative agent of a highly contagious infectious disease that induces upper respiratory tract infections, as well as conjunctiva and cornea ulcers. Feline herpesvirus 1 is considered the main etiological agent of respiratory infections in cats, and, according to experts, about 50–70% of respiratory infection cases are associated with this pathogen.

Objective. Isolation of feline viral rhinotracheitis agent from pathological material of diseased animals in cell culture; its identification and study of antigenic properties.

Materials and methods. To isolate the virus in vitro, a trypsinized primary feline embryo kidney cell culture was used, which was subsequently adapted to continuous feline kidney cell line CRFK. The causative agent of feline viral rhinotracheitis was detected by reverse transcription polymerase chain reaction and real-time polymerase chain reaction using specific primers complementary to the amplified complementary DNA fragments. The virus neutralizing antibodies were detected in the sera of immunized rabbits by virus neutralization test using continuous feline kidney cell CRFK monolayer.

Results. It was found that feline viral rhinotracheitis agent is detected in the conjunctival, nasal, and oropharyngeal swabs. It is replicated with the pronounced cytopathic effect in the primary and subcultured feline embryo kidney cells and in continuous feline kidney cell culture CRFK. The infectious activity titre 72 hours post inoculation was (6.50 ± 0.25) and (7.40 ± 0.22) lg TCID50 /mL, respectively.

Conclusion. Feline herpesvirus 1 isolate obtained as a result of the study and designated as Lavr strain, can be used for the manufacture of diagnostic products and means of specific prevention of feline viral rhinotracheitis in cats.

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