Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was described as an RNA virus of the coronavirus disease 2019 (COVID-19) in human beings (Zhu and others, 2020 ZHU, N.; ZHANG, D.; WANG, W. et al. A Novel Coronavirus from patients with pneumonia in China, 2019. N. Engl. J. Med., v.382, p.727-733, 2020. ), and detected in different animal species worldwide, including dogs, cats, wild felids, minks, and non-human primates .

Toxoplasmosis is a relevant parasitic infection in sheep, with ovine meat an important source of human exposure. Accurate detection of the early immune response to Toxoplasma gondii is essential for preventing reproductive losses and improving diagnostic strategies. This study evaluated the kinetics of the acute immune response in eighteen sheep experimentally exposed to live tachyzoites or immunized with parasite-derived glycoconjugates (GlyC). Animals were divided into three groups and injected with saline solution, tachyzoites, or glycoconjugates combined with an adjuvant. Infected sheep developed specific IgM antibodies against both lysate and glycoconjugate antigens from day 4, and IgG against glycoconjugates from day 12 post-infection. Glycoconjugate-immunized sheep produced IgM against lysate antigens from day 4, and IgG against both antigens from day 12. Flow cytometry revealed a significant increase in circulating CD8+ T cells and a reduction in MHC class II+ cells on day 60 in the infected group. These findings demonstrate the early humoral and cellular immune response profiles following infection or GlyC immunization. This supports their future application in diagnostic tests or as vaccine candidates against toxoplasmosis in sheep.

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis, a significant infectious disease that affects small ruminants and poses economic chal-lenges to livestock production. This study aimed to assess the seroprevalence of C. pseudotuberculosis in goats from Espírito Santo state, Brazil, and identify risk factors associated with the infection by the bacterium. Serum samples from 145 goats were analyzed using an indirect enzyme-linked immunosorbent assay (ELISA). The overall seroprevalence was found to be 34.5%. Risk factors significantly associated with infec-tion included the presence of abscesses and the absence of veterinary assistance on farms. The findings emphasize the need for improved management practices and vet-erinary oversight to mitigate caseous lymphadenitis transmission. This research pro-vides critical insights into the epidemiology of caseous lymphadenitis in goats from Espírito Santo, informing strategies for an effective disease control.

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis, a significant infectious disease that affects small ruminants and poses economic challenges to livestock production. This study aimed to assess the seroprevalence of C. pseudotuberculosis in goats from Espírito Santo state, Brazil, and identify risk factors associated with infection by the bacterium. Serum samples from 145 goats were analyzed using an indirect enzyme-linked immunosorbent assay (ELISA). The overall seroprevalence was found to be 34.5%. The risk factors significantly associated with infection included the presence of abscesses and the absence of veterinary assistance on farms. The findings emphasize the need for improved management practices and veterinary oversight to mitigate caseous lymphadenitis transmission. This research provides critical insights into the epidemiology of caseous lymphadenitis in goats from Espírito Santo, informing effective disease control strategies.