title: First molecular characterization of visna/maedi viruses from naturally infected sheep in Turkey.
abstract: Recent worldwide serological and genetic studies of small ruminant lentiviruses (SRLV) have led to the description of new genotypes and the development of new diagnostic tests. This study investigated the detection and molecular characterization of visna/maedi virus (VMV) infection in serum and blood samples from pure and mixed sheep breeds acquired from different regions in Turkey using ELISA and PCR techniques. The prevalence of VMV was 67.8 % by ELISA and/or LTR-PCR with both assays showing a medium level of agreement (kappa: 0.26; ± 0.038 CI). Positivity of VMV in sheep increased according to the age of the animal, although PCR positivity was higher than ELISA in young individuals. Phylogenetic analysis of 33 LTR sequences identified two distinct clades that were closely related to American and Greek LTR sequences. Phylogenetic analysis of 10 partial gag gene sequences identified A2, A3, A5, A9, A11 subtypes of genotype A SRLVs. In vitro culture of all isolates in fetal sheep lung cells (FSLC) showed a slow/low phenotype causing less or no lytic infection compared with infection with the WLC-1 American strain characterized by a rapid/highly lytic phenotype. Phylogenetic analysis revealed that Turkish VMV sequences preceded the establishment of American or Greek strains that were associated with the migration of sheep from the Middle East to Western Europe several centuries ago. This is the first study that describes Turkish VMV sequences with the molecular characterization of LTR and gag genes, and it strongly suggests that SRLV-genotype A originated in Turkey.
authors.affiliation: Faculty of Veterinary Medicine, Department of Virology, Mustafa Kemal University, Hatay, Turkey. dilekmnm@gmail.com
authors.forename: Dilek
authors.initials: D
authors.lastname: Muz
authors.forename: Tuba Ciğdem
authors.initials: TC
authors.lastname: Oğuzoğlu
authors.forename: Sergio
authors.initials: S
authors.lastname: Rosati
authors.forename: Ramses
authors.initials: R
authors.lastname: Reina
authors.forename: Luigi
authors.initials: L
authors.lastname: Bertolotti
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Burgu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001483:Base Sequence; D004797:Enzyme-Linked Immunosorbent Assay; D015683:Gene Products, gag / Q000737:chemistry; D015750:Genes, gag; D016679:Genome, Viral; D008168:Lung / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011021:Pneumonia, Progressive Interstitial, of Sheep / Q000453:epidemiology / Q000821:virology*; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D016036:Seroepidemiologic Studies; D012756:Sheep; D020079:Terminal Repeat Sequences; D014421:Turkey / Q000453:epidemiology; D014790:Visna-maedi virus / Q000145:classification / Q000235:genetics* / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D015683:Gene Products, gag