Evaluating the Diversity of the Feline Immunodeficiency Virus (FIV): A Leopard Perspective

Abstract

To obtain more insights into the prevalence and diversity of species-specific Feline Immunodeficiency Virus (FIV) strains in naturally occurring felid species, 26 leopards (Panthera pardus) from the Kruger National Park (KNP), South Africa, were sampled. Prevalence was determined using a PCR protocol designed to target a 577 bp fragment in the pol-RT gene. Overall prevalence of FIV Ppa was estimated at 73%, with no difference in prevalence between male and female leopards. Consistent with previous FIV studies on other felid species, prevalence appears to increase with age (adult = 84%; subadult = 43%). Phylogenetic analyses of these novel sequences were conducted against a revised FIV pol-RT species-specific reference dataset using both Bayesian and maximum likelihood methods. Within FIV Ppa two distinct evolutionary groupings are present, which suggests the possibility of geographic variation within FIV Ppa and the possibility of distinct subtypes, similar to what has been found in lions (Panthera leo) and domestic cats (Felis catus). The larger FIV Ppa dataset provides new insights into the epidemiology of this under-studied FIV strain and with such high prevalence rates, further studies should focus on immunological and clinical consequences of FIV in wild felids.Key words: FIV diversity, FIV reference dataset, geographic variation, Kruger National Park, Panthera pardus, FIV pol-RT. INTRODUCTIONLentiviruses (Retroviridae) such as the well-known Human Immunodeficiency Virus (HIV) are not unique to humans and have been isolated from a number of mammalian taxa (Miller, Cairns, Bridges & Sarver, 2000). For example, two well-studied lentiviruses in animals include the primate associated Simian Immunodeficiency Virus (SIV) and the feline associated Feline Immunodeficiency Virus (FIV). HIV in humans represents a recent cross-species transmission of SIV from non-human primates, and apart from SIV, FIV represents the only other well-studied natural animal model to explain the evolution of Immunodeficiency Viruses in mammals. In fact, HIV, SIV and FIV are structurally, genomically and seemingly pathogenically similar (Pedersen, Yamamoto, Ishida & Hansen, 1989;Bendinelli et al., 1995;Miller et al., 2000;O'Brien, Troyer, Roelke, Marker & Pecon-Slattery, 2006). FIV (previously feline T-lymphotropic lentivirus) was first described in the domestic cat (Felis catus) nearly 30 years ago and has since been detected in several nondomestic felids Brown, Miththapala & O'Brien, 1993;Troyer et al., 2005 , African lion (Panthera leo -FIV Ple ) Troyer et al., 2005), puma (Puma concolor -FIV Pco ) , Pallas cat (Otocolobus manul -FIV Oma ) (Troyer et al., 2005;, bobcat (Lynx rufus -FIV Lru ) , cheetah (Acinonyx jubatus -FIV Aju ) (Troyer et al., 2005), leopard (Panthera pardus -FIV Ppa ) Troyer et al., 2005) et al., 2012). In some instances, these subtypes are also geographically confined (Troyer et al., 2005;. Leopards are the largest of the spotted felids found in Africa (Skinner & Chimimba, 2005) and have a distribution that exte...