ANALYSIS OF THE GENETIC DIVERSITY AND PHYLOGENETIC RELATIONSHIP OF ITALIAN ISOLATES OF FELINE IMMUNODEFICIENCY VIRUS INDICATES A HIGH PREVALENCE AND HETEROGENEITY OF SUBTYPE-B

The genetic diversity of 32 Italian isolates of feline immunodeficienc y virus (FIV) was studied. Isolates were obtained from domestic cats l iving in different areas. Sequence data were obtained from a 308 bp fr agment of the p25 region of the gag gene. Phylogenetic relationships a mong these sequences and previously published sequences were determine d. All the Italian isolates could be assigned to subtype B; however, f our isolates formed two separate clusters and may represent genetic ou tliers. The reliability of classification results was confirmed by rep eating the phylogenetic analysis with DNA sequences from the entire ga g genes of two isolates and from the surface glycoprotein domain of th e env gene of four isolates. It is concluded that the short segment of gag used permits reliable genotyping of FIV isolates. The study also shows that subtype B is largely prevalent in Italy.