Search

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. [ABSTRACT FROM AUTHOR]

A Maedi-Visna virus (MVV) infection was diagnosed in a 10-month-old lamb from a Turkish flock. The animal suddenly showed nervous signs and died within 2 days. At necropsy, different pulmonary and nervous lesions were observed. A Coenurus cerebraliscyst was also present in the right-brain hemisphere. Severe nonpurulent meningoencephalitis and lymphoproliferative pneumonia were detected by histopathology. MVV proviral DNA was demonstrated by polymerase chain reaction (PCR) in formalin-fixed and paraffin-embedded samples collected from the brain and the lungs. This unusual report in a young animal confirms that not only adult sheep but also lambs can develop MVV disease. Th e hypothesis that concurrent nervous and pulmonary diseases increase the severity of the lesions due to MVV and reduce the incubation time should be better evaluated. [ABSTRACT FROM AUTHOR]

Viral infections cause important problems and significant economic loses in sheep and goats that can be protected by an investigation of infections. This study aimed to determine the sheep and goat viral infections including bluetongue virus (BTV), maedi-visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) in Kirikkale city located in Central Anatolia region of Turkey. Blood samples collected from 279 sheep and 146 goats were tested by ELISA, RT-nested PCR and nested PCR. It was detected that antibody response to BTV (49.8%), CAEV (7.5%) and MVV (19.4%) were seropositivity values in all serum samples. BTV (2.87%) and MVV (9.25%) antigens were detected in seropositive whole blood samples via RT-nested PCR and nested PCR but not CAEV. It was found that double positive animals (14.6%) for MVV and BTV in sheep but not goat. As a conclusion sheep and goat were infected with naturally BTV, CAEV and MVV in Kirikkale region. This study showed that this the first report for BTV, MVV and CAEV infections from Kirikkale region. Therefore infections are needed to be further investigations to determine detailed survey studies. [ABSTRACT FROM AUTHOR]

The maedi-visna virus (MVV) is distributed worldwide and, to date, no epidemiological surveys have been carried out using ELISA testing in Turkey. The aims of this study were as follows: i) to verify the diagnostic performance of a home-made ELISA test (HM-ELISA) using Turkish ovine sera in comparison with other commercially available ELISA tests, and ii) to perform a preliminary epidemiological survey in Istanbul province. The MVV seroprevalence in Istanbul province was 15.3%. Older sheep were 5 times more likely to be positive than younger animals, ewes were 3 times more likely to be positive than rams, and all the Red Karaman and White Karaman sheep tested were seronegative. The performance of the HM-ELISA and that of the other commercial tests using Turkish ovine serum samples was similar; therefore, the HM-ELISA test is suitable for use in extensive epidemiological surveys and eradication programs in Turkey. [ABSTRACT FROM AUTHOR]