A Combined Approach for the Characterization of Small Ruminant Lentivirus Strains Circulating in the Islands and Mainland of Greece.

Simple Summary: Small ruminant lentiviruses are a group of viruses characterized by a high genetic and antigenic variability. In the absence of control measures, they are characterized by high prevalence in goat and sheep farms. In Greece, a country characterized by one of the highest small ruminant populations in Europe, SRLVs are well-known pathogens, but so far, few studies have investigated the circulating viral strains and their prevalence in the islands and mainland. The results of this research highlighted the presence of both A and B subtypes as well as the predominance of a novel A viral cluster. In many cases, the combined serological–molecular approach allowed us to identify more than one viral subtype in a single farm. Small ruminant lentiviruses are a group of viruses infecting goat and sheep worldwide. These viruses exhibit an extraordinary degree of genetic and antigenic variability that severely influence in vivo and in vitro features, as well as diagnostic test results. Small ruminant farming is the most important animal farming business in Greece, with a high impact on the Greek primary economy. Although SRLV infection and its impact on animal production are well established in the country, little is known about the circulating SRLV strains and their prevalence. The aim of this study was to characterize SRLVs circulating in Greece with a combined serological and molecular approach, using the bulk milk matrix collected from 60 farms in different municipalities. This study allowed us to estimate a seroprevalence of around 52% at the herd level. The B1, B2 and A3 subtypes and a novel A viral cluster were identified. Moreover, the amplicon sequencing method allowed us to identify more than one viral subtype in a sample. These results again confirm the high variability of these viruses and highlight the importance of the constant monitoring of viral evolution, in particular in antigens of diagnostic interest. [ABSTRACT FROM AUTHOR]