Frequency of Toxoplasma gondii antibodies in tufted capuchin monkeys (Cebus apella nigritus) from an ecological station in the State of São Paulo, Brazil

Toxoplasmosis is a worldwide zoonosis caused by Toxoplasma gondii, an obligate intracellular parasite protozoan. A large percentage of animals presents specific antibodies caused by a previous exposition, resulting in a chronic infection. Felides are the definitive hosts and the other warm-blooded animals, including primates, are the intermediate hosts. This study was aimed to determine the prevalence of T. gondii infection in free-living tufted capuchin monkeys (Cebus apella nigritus) from an ecological station located on Mata de Santa Teresa, Ribeirão Preto, SP, Brazil. T. gondii antibodies were analyzed by modified agglutination test (MAT) in serum samples of 36 tufted capuchin monkeys, considering eight as cut-off titer. From the studied animals, 3/36 (8.33%; CI95% 3.0-21.9%) presented T. gondii antibodies, all with titer 32. No significative difference was observed relating to the sex (1/3 male and 2/3 female), and to the age (1/3 young and 2/3 adult) (P>0.05). Thus, these results demonstrate the presence of T. gondii antibodies in primates from São Paulo state.

Kinetics of epsilon antitoxin antibodies in different strategies for active immunization of lambs against enterotoxaemia

Enterotoxaemia, a common disease that affects domestic small ruminants, is mainly caused by the epsilon toxin of Clostridium perfringens type D. The present study tested four distinct immunization protocols to evaluate humoral response in lambs, a progeny of non-vaccinated sheep during gestation. Twenty-four lambs were randomly allocated into four groups according to age (7, 15, 30 and 45 days), receiving the first dose of epsilon toxoid commercial vaccine against clostridiosis with booster after 30 days post vaccination. Indirect ELISA was performed after the first vaccine dose and booster to evaluate the immune response of the lambs. Results showed that for the four protocols tested all lambs presented serum title considered protective (≥0.2UI/ml epsilon antitoxin antibodies) and also showed that the anticipation of primovaccination of lambs against enterotoxaemia conferred serum title considered protective allowing the optimization of mass vaccination of lambs.

Development of an indirect ELISA to detect Corynebacterium pseudotuberculosis specific antibodies in sheep employing T1 strain culture supernatant as antigen

Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis (CLA), a chronic disease that affects goats and sheep, characterized by granuloma formation in subcutaneous and internal lymph nodes. CLA causes significant economic losses to commercial goat herds. In this study, we aimed to test secreted antigens secreted from T1 strain bacteria grown in brain heart infusion (BHI) broth in an indirect ELISA system to determine the presence of specific immunoglobulins against C. pseudotuberculosis. We analyzed the BHI antigen electrophoretic profile and the recognition pattern by infected sheep sera samples. The ELISA results were compared with multiplex PCR assay and IFN-gamma production. The ELISA was able to discriminate between negative and positive animals, with a sensitivity of 89% and a specificity of 99%, using microbiological isolation as gold standard. When this assay was compared with multiplex PCR and specific IFN-gamma quantification, six discrepant results were found among thirty-two samples. We concluded that the ELISA using antigens secreted from C. pseudotuberculosis T1 strain growth in BHI broth culture can be used for the serodiagnosis of CLA in sheep.

Detection of specific antibodies in cows after injection of PPD

The diagnosis of bovine tuberculosis aims to identify the immune response against mycobacterial antigens. Although Single Intradermal Comparative Cervical Tuberculin test (SICCT) is broadly used for first identification of the disease, the performance of ELISAs has been investigated for diagnosis improvement. The present study expected to find out the influence of intradermal skin tests on the results of ELISAs using the recombinant proteins MPB70 and MPB83 as antigens on cows from a naturally infected herd. Results were analyzed by the F-test, Mann-Whitney and Friedman tests Although comparable to both proteins, results showed that positive animals presented a tendency of augment reactivity to MPB70, representing a tendency for a booster effect, but not to MPB83.

Occurrences of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in sheep from four districts of Tocantins state, Brazilian Legal Amazon Region

Toxoplasmosis and neosporosis have been recognized as economically important diseases with considerable impact on the livestock industry. Little is known concerning the occurrence of Toxoplasma gondii and Neospora caninum in sheep from Tocantins state, Brazil. Here, we investigated antibodies against these parasites and associated factors in 182 sheep from Araguaína, Santa Terezinha do Tocantins, Arguianópolis and Palmeiras do Tocantins districts, Tocantins. Sheep sera were assayed for T. gondii and N. caninum IgG antibodies by indirect fluorescence antibody test (IFAT), using cut-off point at a dilution of 1:40 and 1:25 respectively. The prevalence of seropositive animal for T. gondii was 13.74% and 13.74% for N. caninum. None of the characteristics studied including reproductive problems, presence of cats, presence of dogs and veterinary care (p>0.05) was associated with occurrence of T. gondii or N. caninum infection. Only breed was identified as associated factor for the occurrence of toxoplasmosis in sheep (p<0.05). The present study is the first report on serum occurrence of T. gondii and N. caninum in sheep from the state of Tocantins, Brazil.