Leptospira spp. in horses in southern Brazil: Seroprevalence, infection risk factors, and influence on reproduction.

Leptospirosis in horses is often associated with reproductive disorders. In the southern states of Brazil, horses are used for various jobs and cultural practices; nevertheless, serological surveillance for Leptospira is rare. Therefore, the objective of this study was to determine the seroprevalence of Leptospira spp. in horses in southern Brazil, as well as to identify the risk factors for infection and its impacts on reproduction. We performed microscopic agglutination tests for 12 serovars that corresponding 9 serogroup (Sejroe, Icterohaemorrhagiae, Australis, Pyrogenes, Pomona, Canicola, Grippotyphosa, Tarassovi and Ballum) in 595 samples from 60 herds. A brief history was obtained to analyze risk factors for reproductive disorders. A total of 45.9% of the tested horses were seropositive, of which the most frequent serogroups were Icterohaemorrhagiae (Icterohaemorrhagiae and Copenhageni serovars) and Ballum (Ballum serovar). Simple infections were found in 45.4% of seropositive animals, while mixed infections occurred in 54.6% of horses. There was a correlation between seropositivity and age and sex, that is, seropositivity was more frequent in animals over 6 years old and in females. There was no correlation between seropositivity and reproductive disorders. We conclude that there is a high seroprevalence of Leptospira spp. in southern Brazil with predominance of Icterohaemorrhagiae serogroup, mainly in older animals. Location, breeds, contact with dogs or other domestic animals are not risk factors, whereas gender is a risk factor. Reproductive disorders are not due to leptospirosis in the study region.

Relation of reproductive disturbance in sheep and Leptospira interrogans serovar Icterohaemorrhagiae infection: Impacts on cellular oxidation status.

This study evaluated the seropositivity of Brucella abortus and Leptospira interrogans in ewes with reproductive disturbances in southern Brazil and verified the creatine kinase (CK) activity and oxidation status via assessment of superoxide dismutase, glutathione peroxidase and glutathione transferase in serum of seropositive animals for L. interrogans serovar Icterohaemorrhagiae. For Leptospira infection 381 animals with clinical history of reproductive disturbance from Planalto Serrano de Santa Catarina (Brazil) were analyzed, showing an occurrence for L. interrogans of 20.2% from which 81.8% were seropositive for L. interrogans Icterohaemorrhagiae. Serovars Wolfii, Grippothyphosa, Bratislava, Canicola and Butembo were also identified. In the case of B. abortus, positive cases were identified by buffered acidified antigen, finding 14 positive samples, but none of them were positive after a second test (2-mercaptoethanol), showing the absence of relationship between infection with B. abortus and abortion in the tested individuals. Serum reactive oxygen species (ROS) levels and CK activity were found higher in animals positive for Leptospira infection, presenting higher titrations (1:320) than non-infected individuals. Serum glutathione peroxidase activity was higher in positive animals with titrations 1:160 and 1:320, while serum glutathione S-transferase was higher in positive individuals only for titrations 1:320. Serum superoxide dismutase showed lower activity in infected animals with titrations of 1:320. Our results show the region of Planalto Serrano de Santa Catarina with a high occurrence levels of sheep infected by L. interrogans serovar Icterohaemorrhagiae, from which animals with high titrations (1:320) present oxidative stress elicited by excessive ROS production, triggering the stimulation of antioxidant systems to counter this excess. In summary, ovine with higher titrations (1:320) present oxidative damage that can contribute to disease pathophysiology.

[Occurrence of antibodies and risk factors for infection for Toxoplasma gondii in dogs in the cities of Lages and Balneário Camboriú, Santa Catarina State, Brazil]. / Ocorrência de anticorpos e fatores de risco para infecção por Toxoplasma gondii em cães, nas cidades de Lages e Balneário Camboriú, Santa Catarina, Brasil.

The aim of this study was to identify the occurrence of antibodies and risk factors for infection for Toxoplasma gondii in dogs in the cities of Lages and Balneário Camboriú, Santa Catarina State, Brazil. Blood samples from 400 domiciliated dogs were processed for antibody detection against T. gondii by indirect immunofuorescence antibody test (IFAT). The following variables were obtained by questionnaire: breed, age, sex, diet, environment, presence of cats and street access. A Chi-Square test was performed to verify the association between the seroprevalence with the studied variables. From all evaluated dogs, 89 (22.3%) had antibodies against T. gondii. A total of 52 (26%) and 37 (18.5%) dogs were positive for T. gondii in Lages and Balneário Camboriú, respectively. No statistical differences were observed on the prevalences of T. gondii between both cities. Greater occurrences of seropositives for toxoplasmosis were observed in mixed-breed dogs (P = 0.002), who had access to the street (P = 0.003) and received homemade diet (P = 0.028). A strong trend for seropositivity against T. gondii was observed among adult dogs, indicating post-natal exposure, and among those that have previous contact with cats.