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BACKGROUND: Toxoplasmosis is a zoonosis caused by the parasite Toxoplasma gondii. The most affected population are pregnant women, newborns, and immunosuppressed patients. The State of Tabasco, Mexico, has both climatic and biotic conditions that favors the parasite's dissemination and perpetuation, which create its great genetic variability, and can also generate the appearance of more virulent variants. To date, 319 different genotypes have been described worldwide with a wide variation of its virulence levels in murine models. OBJECTIVE: To isolate and genotype Toxoplasma gondii from free-range chicken tissues and to predict the virulence of the obtained isolates by the identification of the associated genetic markers. METHODOLOGY: Heart and brain samples of 12 free-range chickens from seven municipalities of Tabasco were collected to attempt the parasite's isolation in mice. Obtained tachyzoites were propagated in NIH3T3 mice fibroblasts. Parasite DNA was extracted and used to genotype each isolate by Mn-PCR-RFLP of 15 T. gondii genetic markers. RESULTS: Twelve isolates were obtained in total. Two belonged to the genotype ToxoDB #8, tree ToxoDB #28, four ToxoDB #38 and three genotypes which has not yet been described or reported. The genotypes #8, #28 and #38 have already been described in States from the Center and Southwest regions of Mexico, whereas the three new genotypes have not been reported and were identified as the genotypes ToxoDB #344, #345 y #346. In virulence markers ROP18/ROP5, were identified combinations of alleles that can predict high and low virulence in murine models. CONCLUSIONS: Toxoplasma gondii is highly prevalent in Tabasco, Mexico since isolates were obtained in more than 50% of the sampled animals. From these isolates virulent and non-virulent variants in murine model are predicted, which could have a direct impact in public health. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhea virus (BVDV) is considered the most important viral pathogen in ruminants worldwide due to the broad range of clinical manifestations displayed by infected animals. Therefore, infection with BVDV leads to severe economic losses in several countries' beef and dairy industries. Vaccination prevents reproductive failure and gastrointestinal and respiratory disorders caused by BVDV infection. However, considering their limitations, conventional vaccines such as live, attenuated, and killed viruses have been applied. Hence, different studies have described subunit vaccines as an effective and safe alternative for BVDV protection. Therefore, in this study, the ectodomain of E2 (E2e) glycoprotein from NADL BVDV strain was expressed in mammalian cells and used in two vaccine formulations to evaluate immunogenicity and protection against BVDV conferred in a murine model. Formulations consisted of solo E2e glycoprotein and E2e glycoprotein emulsified in adjuvant ISA 61 VG. Five groups of 6 mice of 6-to-8-week-old were immunized thrice on days 1, 15, and 30 by intraperitoneal injection with the mentioned formulations and controls. To evaluate the conferred protection against BVDV, mice were challenged six weeks after the third immunization. In addition, the humoral immune response was evaluated after vaccination and challenge. Mice groups inoculated with solo E2e and the E2e + ISA 61 VG displayed neutralizing titers; however, the E2 antibody titers in the E2e + ISA 61 VG group were significantly higher than the mice group immunized with the solo E2e glycoprotein. In addition, immunization using E2e + ISA 61 VG prevents animals from developing severe lesions in surveyed tissues. Moreover, this group acquired protection against the BVDV challenge, evidenced by a significant reduction of positive staining for BVDV antigen in the lungs, liver, and brain between the experimental groups. Our findings demonstrated that using E2e + ISA 61 VG induces greater BVDV protection by an early humoral response and reduced histopathological lesions and BVDV antigen detection in affected organs, indicating that E2e + ISA 61 VG subunit formulation can be considered as a putative vaccine candidate against BVDV. The efficacy and safety of this vaccine candidate in cattle requires further investigation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Gómez-Romero, Arias, Verdugo-Rodríguez, López, Valenzuela-Moreno, Cedillo-Peláez and Basurto-Alcántara.)