First molecular characterization of visna/maedi viruses from naturally infected sheep in Turkey.

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.

First molecular characterization of feline immunodeficiency virus in Turkey.

In this study, strains of feline immunodeficiency virus (FIV), designated TR-D, TR-Mo and TR-Mi, isolated from three cats in Turkey, were characterized. PCR products (859 bp) from the envelope (env) gene region were amplified and sequenced, and possible geographical differences in the env gene region of Turkish FIV strains are discussed. Phylogenetic analysis of two strains showed that FIV subtype B was present in Turkey. Phylogenetic analysis showed that one new Turkish FIV strain occupies a separate branch from known clusters (subtypes A to E) from the USA, Canada, Europe and Japan.

Molecular characterization of Bovine virus diarrhea viruses species 2 (BVDV-2) from cattle in Turkey.

Five BVDV species 2 (BVDV-2) isolates were detected from cattle in Turkey. Phylogenetic analysis was performed based on the 5' untranslated regions (UTRs) and E2 coding gene regions, respectively. The isolates were closely related to BVDV-2a strains from North America and Canada used as references. This is the first report of the detection of BVDV-2 in naturally infected Turkish cattle. It is important to consider BVDV-2 for planning future BVDV control and vaccination programs in Turkey.

Distribution of G (VP7) and P (VP4) genotypes of group A bovine rotaviruses from Turkish calves with diarrhea, 1997-2008.

Group A rotaviruses are major enteric pathogens of calves. In order to investigate the genetic diversity of bovine rotaviruses (BRVs), a collection of 53 BRVs, detected from diarrheic calves from several Turkish geographical areas, between 1997 and 2008 was analyzed by RT-PCR for specificities of the outer capsid proteins VP7 (G type) and VP4 (P type), for the first time. Overall, G6 was the predominant G type, detected in 40/53 samples (75.4%), while P[11] was the predominant P type, detected in 52/53 samples (98.1%). The most common VP7/VP4 combinations were G6P[11] (60.3%) and G10P[11] (24.5%). Mixed infections were identified in 7/53 samples (13.2%). In the VP7 region the G6P[11] viruses were similar to other ones detected worldwide, forming an independent G6 lineage, distantly related to the G6 gene of the vaccine G6P[1] strain NCDV (90.1% amino acid identity), and suggesting that G6P[11] viruses represent a genetically stable BRV strain. The study of G and P type diversity is pivotal to understand the efficacy of the existing rotavirus vaccines and to provide the basis of future prophylaxis tools against rotaviral diarrhea of calves.

Maturation of immunoglobulin G avidity after inactive gE deleted bovine herpesvirus type 1 (BHV-1) marker vaccination.

Particularly for countries in which the prevalence of infection is high, prevention and control of infectious bovine rhinotracheitis (IBR) can be done by vaccination programs. Recently, marker vaccines have been used in the control and eradication of bovine herpesvirus type 1 (BHV-1) infection. Vaccine protection and virus circulation were estimated by individual serological testing using both gB- and gE-ELISA blocking tests. However, the efficacy of vaccines in terms of avidity maturation for BHV-1 infection has not yet been clarified. A total of 40 animals divided into two groups were vaccinated twice at 6-mo intervals with either commercial or in-house killed gE-deleted marker BHV-1 vaccines, respectively. Immunoglobulin G avidity maturation for BHV-1 was monitored in serum samples collected 1 mo postvaccination and compared between groups. The avidity index (AI) was expressed as a percentage and results were presented as mean AI + SD. The overall data showed that optical density (OD) values in wells with or without urea treatment had obviously increased. In relation to this, geometric means of AIs increased from 71% to 96% after primary and booster vaccinations, respectively. Based on group-specific data, mean AI was calculated to be 68.99 +/- 24.6 after the primary vaccination, and 96.74 +/- 8.3 after the booster vaccination in group I. For group II, the mean AI for primary vaccination was 57.40 +/- 23.9, and it increased to 97 +/- 8.9 after the booster vaccination. The increase in AI for both groups after the second vaccinations was found to be significant (p < 0.001).

Prevalence, distribution, and host range of Peste des petits ruminants virus, Turkey.

Peste des petits ruminants virus (PPRV, genus Morbillivirus), which causes a severe disease in sheep and goats, has only recently been officially declared to be present in Turkey. We carried out a study to determine the prevalence, distribution, and host range of PPRV in Turkey. A total of 1,607 animals, reared in 18 different locations, were monitored for the presence of antibodies to PPRV and the related virus of large ruminants, Rinderpest virus (RPV). Only two farms had animals that were free of antibody responses to either disease. Prevalence for PPRV infection varied (range 0.87%-82.6%) and was higher in sheep (29.2%) than in goats (20%). The overall antibody responses to PPRV and RPV were 22.4% and 6.28%, respectively. Two PPRVs of lineage 4, which comprises many other PPRVs whose origins are in the Middle East, the Arabian Peninsula, and southern Asia, were isolated from Turkish sheep.