Naturally occurring feline leukemia virus subgroup A and B infections in urban domestic cats

Abstract

A nested-PCR (n-PCR) was used to detect feline leukemia virus (FeLV) proviral DNA in blood samples from 464 sick and 608 healthy domestic cats (Felis catus) selected by convenience, and a significantly high prevalence of FeLV infection was observed. n-PCR results revealed the presence of FeLV proviral DNA in 47.2 % of sick cats and 47.4 % of healthy cats. Phylogenetic analysis revealed that FeLV samples from healthy or sick cats were grouped into separate clades. We determined FeLV subgroups by an n-PCR based on the envelope (env) gene. The partial env gene of FeLV Minas Gerais (MG) samples were compared to various exogenous FeLV isolates and endogenous (enFeLV) provirus from the same region. FeLV-B MG samples were more similar to endogenous sequences and to natural FeLV-B isolates than to either FeLV-A or FeLV-C. The results revealed the circulation of FeLV-B in large populations of urban domestic cats in Brazil.