Cumulatively, our findings suggest that LemA and Erp Y-like proteins act as adhesins and are able to protect against mortality, but not against tissue lesions. Moreover, AddaVax is a novel adjuvant with potential for improving the immunogenicity of leptospiral vaccines.

Neosporosis is a disease caused by the protozoon Neospora caninum that leads to significant economic losses in many countries. In the present study, we report on use of the recombinant protein NcSRS2 of N. caninum expressed in Pichia pastoris in an indirect immunoenzymatic assay (ELISA) for diagnosing neosporosis infection in sheep and dogs. We observed that the ELISA test yielded specificity of 94.5% and sensitivity of 100% for sheep and specificity of 93.3% and sensitivity of 100% for dogs. We observed that the sensitivity was higher than shown by the indirect fluorescent antibody test, and this was confirmed by means of Western blot. The results from this study suggest that the recombinant protein expressed in P. pastoris is a suitable antigen for use in immunodiagnosis to detect N. caninum in two important species exposed to this parasitosis.

Leptospirosis is a zoonotic disease caused by pathogenic spirochetes from the genus Leptospira, which includes 20 species and more than 300 serovars. Canines are important hosts of pathogenic leptospires and can transmit the pathogen to humans via infected urine. Here, we report the phenotypic and molecular characterization of Leptospira interrogans isolated from Canis familiaris in Southern Brazil. The isolated strain was characterized by variable-number tandem-repeats analysis as L. interrogans, serogroup Icterohaemorrhagiae. In addition, the isolate was recognized by antibodies from human and canine serum samples previously tested by microscopic agglutination test. Ultimately, the expression of membrane-associated antigens (LipL32 and leptospiral immunoglobulin-like proteins) from pathogenic leptospires using monoclonal antibodies was detected by indirect immunofluorescence assay. In conclusion, identification of new strains of Leptospira can help in the diagnosis and control of leptospirosis.

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The parasite Neospora caninum is the main cause of abortion in cattle in many countries around the world, so a vaccine is a rational approach method for the control of the disease. An effective vaccine should be able to prevent both, the horizontal and vertical transmission of N. caninum. In this study, the immune vaccinal response of the recombinant protein rNcSRS2 of N. caninum expressed in Pichia pastoris and formulated with water-in-oil emulsion, xanthan gum, and alum hydroxide was assessed in an experimental murine model. Groups of 10 Balb/c mice were subcutaneously inoculated with two doses of prNcSRS2 twenty-one days apart. After the second immunization, four mice from each group were euthanized, and splenocytes were stimulated ex vivo with recombinant protein. The IgG dynamics were evaluated by indirect ELISA, and the splenocytes cytokines transcription by qPCR. All groups elicited specific antibodies against prNcSRS2, with the water-in-oil group showing significantly (p .05) elevated titers compared to the other groups. The prNcSRS2 protein alone did not induce a significant ex vivo splenic transcription level of IFN-c, TNF-a, IL-4, IL-10, and IL-12 cytokines, except for IL-17A, and the adjuvant associations with the prNcSRS2 protein induced different cytokine transcription profiles. The water-inoil emulsion modulated the expression of TNF-a; the xanthan gum modulated IL-4, IL-10, and IL-12; and alum hydroxide modulated IFN-c, TNF-a, IL-4, IL-10, and IL-12. In conclusion, it was found that the association of the recombinant prNcSRS2 protein with different adjuvants induced different levels of specific antibody, and a distinct splenic cytokine profile in an adjuvant-dependent manner. The mechanisms of adjuvancity activity is complex, so adjuvant formulation may help in the design of efficient vaccine to control Neosporosis.

Bovine herpesvirus (BoHV) glycoprotein E (gE) is a non-essential envelope glycoprotein and the deletion of gE has been used to develop BoHV-1 and BoHV-5 differential vaccine strains. The DIVA (Differentiation of Infected from Vaccinated Animals) strategy, using marker vaccines based on gE-negative BoHV strains, allows the identification of vaccinated or infected animals in immunoassays designed to detect anti-gE antibodies. In this study a codon optimized synthetic sequence of gE containing highly conserved regions from BoHV-1 and BoHV-5 was expressed in Pichia pastoris. Following expression, the recombinant gE (rgE) was secreted and purified from the culture medium. The rgE was identified by Western blotting (WB) using sera from cattle naturally infected with BoHV-1 and/or BoHV-5, or sera from bovines experimentally infected with wild-type BoHV-5. Sera collected from cattle vaccinated with a BoHV-5 gI/gE/US9¯ marker vaccine failed to recognise rgE. Expression of rgE, based on a sequence containing highly conserved regions from BoHV-1 and BoHV-5, in P. pastoris enabled the production of large quantities of rgE suitable for use in immunoassays for the differentiation vaccinated or infected cattle.