Ocorrência da brucelose canina em cães em co-habitação com bovinos, na zona rural de andradina/sp / occurrence of canine brucellosis in dogs co-habitating with cattle in the rural area of andradina, sp

A brucelose é causada por microrganismos da família Brucellaceae, gênero Brucella. É uma doença importante, do ponto de vista da saúde e também do econômico e está incluída no contexto das doenças transmitidas por alimentos. Em virtude do potencial da pecuária de corte e de leite regional e do impacto econômico que a brucelose bovina pode causar na economia, impunha-se uma investigação criteriosa sobre a possível ocorrência de Brucelose nos cães criados na zona rural de Andradina/SP e circunvizinhanças. O experimento foi conduzido na zona rural do município de Andradina-SP, onde foram colhidas cem amostras de sangue de cães adultos, de ambos os sexos e sem raça definida, através de flebocentese da veia cefálica. As amostras depois de coletadas foram acondicionadas em tubos de ensaio e em seguida enviadas ao Lab. Clínico do HV da Fundação Educacional de Andradina, sendo então centrifugadas, posteriormente dessoradas e só então submetidas à Prova do Antígeno Acidificado Tamponado (AAT). Os resultados obtidos com a pesquisa demonstram que,

OCORRÊNCIA DA BRUCELOSE CANINA EM CÃES EM CO-HABITAÇÃO COM BOVINOS, NA ZONA RURAL DE ANDRADINA/SP / OCCURRENCE OF CANINE BRUCELLOSIS IN DOGS CO-HABITATING WITH CATTLE IN THE RURAL AREA OF ANDRADINA, SP

A brucelose é causada por microrganismos da família Brucellaceae, gênero Brucella. É uma doença importante, do ponto de vista da saúde e também do econômico e está incluída no contexto das doenças transmitidas por alimentos. Em virtude do potencial da pecuária de corte e de leite regional e do impacto econômico que a brucelose bovina pode causar na economia, impunha-se uma investigação criteriosa sobre a possível ocorrência de Brucelose nos cães criados na zona rural de Andradina/SP e circunvizinhanças. O experimento foi conduzido na zona rural do município de Andradina-SP, onde foram colhidas cem amostras de sangue de cães adultos, de ambos os sexos e sem raça definida, através de flebocentese da veia cefálica. As amostras depois de coletadas foram acondicionadas em tubos de ensaio e em seguida enviadas ao Lab. Clínico do HV da Fundação Educacional de Andradina, sendo então centrifugadas, posteriormente dessoradas e só então submetidas à Prova do Antígeno Acidificado Tamponado (AAT). Os resultados obtidos com a pesquisa demonstram que,

A new ELISA for determination of potency in snake antivenoms.

A competitive ELISA for potency determination of bothropic equine antivenom was developed and compared to the conventional in vivo ED(50) assay, with the aim of partially substituting the in vivo assay in the monitoring of antivenom immunoglobulin levels. On this purpose, blood samples were taken at different times during and after the immunization protocol of the lot of horses used for production of snake antivenom at the Instituto de Higiene, Uruguay. Both the competitive ELISA and the ED(50) assay were performed on those samples. In addition, a group of five commercial pepsin-digested antivenoms were tested by both methods. A significant (P<0.001) correlation (Pearson's r=0.957) was found between the ELISA titres and the corresponding ED(50) values, indicating that the in vitro test can estimate the neutralizing antibody capacity of the sera as well as the in vivo assay. By means of this new ELISA, it was found that the immunized animals maintained good venom antibody titres, in the order of 20-50% of the maximum achieved, even 10 month after the end of the immunization schedule. The main advantage of our ELISA design is its ability to correctly estimate the neutralization capacity of crude hyperimmune plasma and antivenom sera independently of their antibody composition in terms of whole IgG or F(ab')(2) fragment.

An attenuated Salmonella Enteritidis strain derivative of the main genotype circulating in Uruguay is an effective vaccine for chickens.

We have recently reported that Salmonella enterica serovar Enteritidis (S. Enteritidis) strains circulating in Uruguay, are unevenly distributed among different genetic subtypes, with a predominant genotype that is a common contaminant of poultry-derived food and that accounts for the vast majority of human cases of food-borne disease. Herein, we describe the construction of a genetically-defined aroC derivative (LVR02) of a local strain of S. Enteritidis belonging to the major genetic type. We demonstrated the attenuation and the immunogenicity of that strain in a mouse model, and evaluated it as a vaccine for commercial layer chickens. LVR02 proved to be stable, attenuated, innocuous, immunogenic and to induce protective immunity against a S. Enteritidis challenge when used for oral vaccination. A single oral dose of LVR02 administered to newly hatched chickens induced protection against oral challenge with the parental virulent strain, preventing systemic and persistent intestinal infection and significantly reducing the shedding of the challenge strain in birds' feces. A second vaccine dose at 15 days post-hatching boosted the immunogenicity of the vaccine, and strengthened the protection achieved with a single dose. This strain may represent the basis of a live vaccine to be included in national control programs to reduce circulation of this pathogen in the country.

Intranasal immunization with a colloid-formulated bacterial extract induces an acute inflammatory response in the lungs and elicits specific immune responses.

Nonspecific stimulation of lung defenses by repeated oral administration of immunomodulators, such as bacterial extracts, has shown potential for the prevention of respiratory tract infections. Here, we show that intranasal (i.n.) immunization with a bacterial extract formulated as a colloid induces an acute inflammatory response in the lungs characterized by increased production of CCL and CXCL chemokines and a major influx of dendritic cells (DCs) and neutrophils, with a higher proportion of DCs showing an activated phenotype (high CD80/CD86 expression). Cytokine levels measured in bronchoalveolar-lavage samples showed a small increase in the production of tumor necrosis factor alpha and similar levels of the other cytokines measured (interleukin 10 [IL-10], IL-12, and gamma interferon [IFN-gamma]) in immunized mice compared with control mice. However, the recall response of primed animals after antigenic challenge induced increased expression of IL-12 and IFN-gamma mRNAs in lung homogenates. Overall, all these effects were not due to the lipopolysaccharide content in the bacterial extract. Furthermore, we found that three i.n. doses administered 2 to 3 weeks apart were enough to elicit long-lasting specific serum immunoglobulin G (IgG) and secretory IgA antibody responses. Assessment of IgG subclasses showed a balanced pattern of IgG1-IgG2a responses. The serum total IgE concentrations were also elevated in immunized mice 2 weeks after the third dose, but they significantly decreased soon afterwards. Our results suggest that simple formulations of bacterial extracts administered i.n. are highly immunogenic, eliciting local and systemic immune responses, and may serve as the basis for cost-effective immunotherapies for the prevention and treatment of respiratory infections.