Neospora caninum is recognised for causing cattle abortion, provoking severe economic losses in the livestock industry worldwide. The aim of the present study was to evaluate the reactivation and foetal infection in pregnant heifers inoculated with live N. caninum tachyzoites before puberty. A total of 15 30-month-old pregnant heifers were allocated into four groups: animals inoculated with live tachyzoites of NC-Argentina LP1 isolate before puberty and challenged with live tachyzoites of NC-1 strain at 210 days of gestation (DG) (Group A); animals mock inoculated before puberty and challenged with NC-1 strain at 210 DG (Group B), animals inoculated before puberty but not subsequently challenged (Group C); and noninfected and nonchallenged animals (Group D). The results of this study showed that 100% of animals infected before puberty (Groups A and C) suffered reactivation of the infection at the seventh month of gestation. In addition, in three and two calves from Groups A and C, respectively, congenital infection was confirmed. Interestingly, we provide evidence that the use of live N. caninum tachyzoites in young animals as a strategy to induce protection is neither safe nor effective.

Stenocarpella maydis and S. macrospora are pathogenic fungi that cause Diplodia stalk rot and ear rot in maize. In Argentina, Brazil, South Africa, and Australia, S. maydis in feed causes neuromycotoxicosis in cattle and sheep. In Argentina, we analyzed corn samples from cattle feed without visible fungus and from corn fields in which animals had clinical signs of diplodiosis. Stenocarpella spp. were identified and characterized with conventional PCR. We did not detect S. macrospora in 6 samples; results in another sample were inconclusive. We identified S. maydis in the 5 corn samples consumed by animals that developed diplodiosis, suggesting that S. maydis may cause the disease in Argentina. Direct PCR testing of corn is an efficient method for the identification of S. maydis in feed. This testing could enable rapid decision-making in the field by predicting the onset of diplodiosis, thereby helping to prevent this mycotoxicosis.

Infections with the protozoan Neospora caninum cause abortion in cattle, likely due to the parasite’s replication and excessive inflammation in the placenta. Cathelicidins are host defense peptides known for their antimicrobial and immunomodulatory functions, but their role in N. caninum infections remains elusive. Using bone marrow-derived macrophages (BMDMs) isolated from mice expressing (wild-type, Camp^+/+) and lacking (Camp^−/−) cathelicidins, we investigated the role of endogenous cathelicidin in infections with N. caninum. We show that Camp^−/− macrophages primed with lipopolysaccharide (LPS) had an increased number of intracellular N. caninum tachyzoites, and these macrophages released higher amounts of IL-1β and lactate dehydrogenase (LDH), a marker of cytotoxicity. These findings indicate that cathelicidins contribute to intracellular N. caninum control and inflammation by limiting the activation of the inflammasome, particularly under LPS-induced conditions. This insight reveals the immunomodulatory role of cathelicidins in controlling N. caninum-associated pathologies.

Neospora caninum is a leading cause of abortion in cattle worldwide, yet the role of host genetic background in early immune responses remains incompletely understood. This study compared early transcriptional responses to N. caninum infection in two cattle breeds with contrasting selection histories using a controlled in vivo model. Fourteen-month-old, non-pregnant Argentine Creole and Holstein heifers (n = 8 per breed) were intravenously inoculated with live N. caninum tachyzoites or mock-treated. Peripheral blood mononuclear cells were collected at 7 days post-infection and analyzed by bulk RNA sequencing across the following contrasts: Uninfected breeds, Holstein infection, Argentine Creole infection and infected breeds , capturing the transition from innate immune sensing to early cellular activation.Transcriptomic variation was primarily driven by breed rather than infection status, indicating that responses to infection were deployed upon distinct baseline immune configurations. Under basal conditions, Creole heifers exhibited an interferon-enriched, immune-primed transcriptional profile, whereas Holstein heifers showed greater representation of biosynthetic and translation-related pathways. Following infection, both breeds activated canonical immune pathways; however, their responses differed in magnitude and organization. Creole heifers displayed broader transcriptional remodeling, integrating immune effector functions, lymphocyte proliferation, and trafficking-related processes. In contrast, Holstein heifers showed a more restricted response, characterized by enrichment of cell cycle and metabolic pathways.These findings indicate that host genetic background modulates baseline immune configuration and influences early transcriptional responses to N. caninum infection, providing a framework for understanding how genetic variation may contribute to differences in host–parasite interactions and disease dynamics across cattle populations.