Seroprevalence and risk factors associated with Toxoplasma gondii infection in sheep of Veracruz State, southeast Mexico.

Toxoplasma gondii is widely prevalent in sheep and their products pose a risk to public health. The aim of this study was to identify the seroprevalence and risk factors associated with T. gondii infection in sheep in Veracruz State, Mexico. The study was cross-sectional and it was carried out in thirteen municipalities distributed in three regions of Veracruz State. A total of 414 blood samples were collected from four districts of Veracruz State and analyzed for T. gondii antibodies using enzyme-linked immunosorbent assay. Total seroprevalence was 35.90% (149/414; 95.00% CI = 31.40-40.80). Seroprevalence by the municipality was 10.50% to 85.70% and for the district was 28.80% to 47.80%, respectively. Age, breed and productive status were identified as risk factors associated with T. gondii infection significantly. The infection by T. gondii is widely present in the districts of the Veracruz State with a high seroprevalence and risk factors associated with infection.

Evaluation of in vitro shoot multiplication and ISSR marker based assessment of somaclonal variants at different subcultures of vanilla (Vanilla planifolia Jacks).

The effect of subculture cycles on somaclonal variation of V. planifolia using intersimple sequence repeat (ISSR) markers was analyzed. Nodal segments of 2 cm in length were established in vitro and multiplied by 10 subculture cycles in Murashige and Skoog (MS) medium supplemented with 8.86 µM BAP (benzylaminopurine). After 45 days in each culture, the length and number of shoots per explant were evaluated. For ISSR markers, ten shoots per each subculture and the mother plant were used. Ten ISSR primers were used and a total of 118 bands were obtained. The polymorphism (%) was calculated and a dendrogram based on Jaccard's genetic distance between the subcultures and the donor plant was obtained. These results show that the multiplication rate tends to increase until subculture five, whereas shoot length decreases as the number of subcultures increases. The ISSR markers revealed an increase in the polymorphism percentage after the fifth culture cycle. The dendrogram showed the formation of two groups. The first group, with less genetic variability, is the donor plant and subcultures 1-5; the second group has greater genetic distance and is formed by subcultures 6-10. The results revealed that the number of subcultures with 8.86 µM BAP is a factor that affects the somaclonal variation during in vitro regeneration of V. planifolia. In conclusion, the subculture number affects somaclonal variation and in vitro development of V. planifolia.