Infection with Foamy Virus in Wild Ruminants—Evidence for a New Virus Reservoir?

Abstract

Foamy viruses (FVs) are widely distributed and infect many animal species including non-human primates, horses, cattle, and cats. Several reports also suggest that other species can be FV hosts. Since most of such studies involved livestock or companion animals, we aimed to test blood samples from wild ruminants for the presence of FV-specific antibodies and, subsequently, genetic material. Out of 269 serum samples tested by ELISA with the bovine foamy virus (BFV) Gag and Bet antigens, 23 sera showed increased reactivity to at least one of them. High reactive sera represented 30% of bison samples and 7.5% of deer specimens. Eleven of the ELISA-positives were also strongly positive in immunoblot analyses. The peripheral blood DNA of seroreactive animals was tested by semi-nested PCR. The specific 275 bp fragment of the pol gene was amplified only in one sample collected from a red deer and the analysis of its sequence showed the highest homology for European BFV isolates. Such results may suggest the existence of a new FV reservoir in bison as well as in deer populations. Whether the origin of such infections stems from a new FV or is the result of BFV inter-species transmission remains to be clarified.

Seroprevalence of feline foamy virus in domestic cats in Poland

“…As previously observed ( 3 ), we also confirmed the stronger correlation between the reactivities to Gag and Bet than Gag and Env, however, both antigens reacted with clearly lower number of sera than the Gag antigen. Similar results were noted previously not only for FFVfca but also for other FVs ( 9 , 23 ) and can be explained by the cessation of production of Bet protein after the productive phase of FVs infection and its diminution in the persistent one lessening its diagnostic value ( 33 ). The assay using the Env antigen was primarily developed in order to find an alternative to serotype-specific PCR and neutralisation assays ( 3 , 377, 41 ) for distinguishing between FFVfca serotypes.…”

Detection of small ruminant Lentivirus proviral DNA in red deer from Poland

“…The difficulty in isolating retroviral genetic material from wild ruminants was also observed by Materniak et al, who were able to amplify proviral DNA of Foamy virus (FV) in only one out of 269 tested samples (0.37%), although the presence of specific antibodies was detected in 30% of bison and 7.5% of the deer sera. The authors successfully obtained pol and LTR fragments but failed to amplify the gag fragment [ 37 ]. PCR is less sensitive than serological tests and depends mainly on the specificity of the designed primers and the heterogeneity of the viral genome.…”