Genetic, antigenic and phenotypic comparison of herpesviruses isolated from domestic and wild felids

Abstract

Feline herpesviruses are endemic in free-ranging lions in South Africa. Serological surveillance among free-living felids revealed high levels of exposure to the virus. However, clinical disease in wild felids following FHV-1 infection has been only described in captive populations and reported to be similar to that in the domestic cat. To expand the epidemiological understanding of feline herpesviruses in felids and for disease control, three strains of FHV-1 isolated from a domestic cat (Felis catus) a cheetah (Acinonyx jubatus) and an African wild cat (Felis silvestris) have been compared to determine their relatedness. A region of the herpesvirus DNA polymerase gene was amplified in a nested PCR with consensus degenerate primers to confirm the identity of the isolates. The genetic relatedness were investigated by comparing patterns of genomic DNA cleaved with restriction enzymes SalI and KpnI and the DNA fingerprints generated by different RAPD primers. For antigenic relationships, a panel of nine monoclonal antibodies prepared against a vaccine strain used against domestic cats were tested in a microneutralization assay. In addition, the phenotypic characteristics of the isolates were also compared by their ability to produce plaques in CrFK monolayer cell cultures. With restriction enzyme analysis, it was not possible to make a comparison due to lack of digestion of the genomic DNA of the domestic cat isolate. However, the RAPD-PCR revealed that isolates were closely related but distinct from each other. Only two monoclonal antibodies reacted with the wild isolates; an effect similar to a toxic effect on cell was observed with the domestic isolate. No significant differences of plaque production were observed among the trains. This study provides evidence of a closer evolutionary relationship between the three isolates. The results of the relationships based on the genetic and phenotypic characterization agreed well and both indicated that the viruses from the domestic and wild felids are different but have a high degree of similarity. Copyright