Haemophilus parasuis

The expression of chemokines (CCL-2 and CXCL-8) and cytokines (IL-1α, IL-1β, IL-6, TNF-α, and IL-10) was evaluated by RT-qPCR in colostrum-deprived pigs vaccinated and challenged with Haemophilus parasuis serovar 5. Two vaccines containing native proteins with affinity to porcine transferrin (NPAPTim and NPAPTit) were tested, along with two control groups: one inoculated with PBS instead of antigen (challenge group (CHG)), and another one nonimmunized and noninfected (blank group). The use of NPAPTim and NPAPTit resulted in complete protection against H. parasuis (no clinical signs and/or lesions), and both vaccines were capable of avoiding the expression of the proinflammatory molecules to levels similar to physiological values in blank group. However, overexpression of all proinflammatory molecules was observed in CHG group, mainly in the target infection tissues (brain, lungs, and spleen). High expression of CCL-2, CXCL-8, IL-1α, IL-1β, and IL-6 can be considered one of the characteristics of H. parasuis infection by serovar 5

Assessment by immunoproteomic study of the immune response developed by different subunit vaccines against glässer's disease

Comunicaciones a congreso

Molecular analysis of lungs from pigs immunized with a mutant transferrin binding protein B-based vaccine and challenged with Haemophilus parasuis

38 p.The molecular analysis of pigs vaccinated with a mutant transferrin-binding protein B (Y167A) from Haemophilus parasuis was compared with that performed for unvaccinated challenged (UNCH) and unvaccinated unchallenged (UNUN) pigs. Microarray analysis revealed that UNCH group showed the most distinct expression profile for immune response genes, mainly for those genes involved in inflammation or immune cell trafficking. This fact was confirmed by real-time PCR, in which the greatest level of differential expression from this group were CD14, CD163, IL-8 and IL-12. In Y167A group, overexpressed genes included MAP3K8, CD14, IL-12 and CD163. Proteomics revealed that collagen -1 and peroxiredoxins 2 and 6 were overexpressed in Y167A pigs. Our study reveals new data on genes and proteins involved in H. parasuis infection and several candidates of resistance to infection that are induced by Y167A vaccine. The expression of proinflammatory molecules from Y176A pigs is similar to their expression in UNUN pigsS

Interference and level of economic damage of Alexandergrass on corn.

O objetivo deste trabalho foi avaliar a competitividade e determinar o nível de dano econômico de papuã infestante da cultura do milho. Os tratamentos foram compostos por densidades de milho (2,60; 3,10; 3,65; 4,00; e 4,80 plantas m-1)e dez populações de papuã para cada densidade de semeadura da cultura. Como indicadores de infestação, avaliou-se a população de plantas, área foliar, cobertura de solo e massa seca da parte aérea de papuã. A massa seca da parte aérea do papuã apresentou melhor ajuste ao modelo da hipérbole retangular e às perdas de produtividade de grãos, devido à interferência da planta daninha estimada satisfatoriamente por esse modelo. A semeadura das densidades de milho de 2,60;3,10 e 3,65 plantas m-1 de todas as características avaliadas foram mais competitivas do que as demais na presença do papuã. A semeadura das densidades de 2,60, 3,10 e 3,65 plantas m-1 aumentou o nível de dano econômico, justificando a adoção de medidas de controle do papuã nas populações mais elevadas. Os valores de NDE variaram de 1,58 a 9,37 plantas m-2 para as densidades de 4,00 e4,80 plantas m-1 de milho, as quais foram menos competitivas com o papuã

Transcriptomics of Haemophilus (Glässerella) parasuis serovar 5 subjected to culture conditions partially mimetic to natural infection for the search of new vaccine antigens

11 p.Haemophilus (Glässerella) parasuis is the etiological agent of Glässer’s disease in pigs. Control of this disorder has been traditionally based on bacterins. The search for alternative vaccines has focused mainly on the study of outer membrane proteins. This study investigates the transcriptome of H. (G.) parasuis serovar 5 subjected to in vitro conditions mimicking to those existing during an infection (high temperature and iron-restriction), with the aim of detecting the overexpression of genes coding proteins exposed on bacterial surface, which could represent good targets as vaccine candidates. The transcriptomic approach identified 13 upregulated genes coding surface proteins: TbpA, TbpB, HxuA, HxuB, HxuC, FhuA, FimD, TolC, an autotransporter, a protein with immunoglobulin folding domains, another large protein with a tetratricopeptide repeat and two small proteins that did not contain any known domains. Of these, the first six genes coded proteins being related to iron extraction. Six of the proteins have already been tested as vaccine antigens in murine and/or porcine infection models and showed protection against H. (G.) parasuis. However, the remaining seven have not yet been tested and, consequently, they could become useful as putative antigens in the prevention of Glässer’s disease. Anyway, the expression of this seven novel vaccine candidates should be shown in other serovars different from serovar 5.S

Altered indirect hemagglutination method for easy serotyping of Haemophilus parasuis [Método de Hemaglutinação Indireta alterado para facilitar a sorotipificação de Haemophilus parasuis]

ABSTRACT Glässer's disease is an emergent bacterial disease that affects swine husbandries worldwide causing important economic losses. The aetiological agent, Haemophilus parasuis, is currently divided in fifteen serovars but an increasing number of non-typeable serovars have been reported. Indirect hemagglutination (IHA) is indicated as a serotyping method for H. parasuis. In the present study, we describe an additional step that aims to work around a possible obstacle in the original protocol that may compromise the outcome of this assay. We observed that the choice of anticoagulant for blood collection influences and/or impairs spontaneous adsorption of H. parasuis antigens on sheep red blood cells (SRBCs). However, regardless of the anticoagulant used, chemical treatment of SRBCs with tannic acid induces a stable antigen adsorption (sensitization step). The addition of 1% BSA to SRBCs washing buffer and to antisera dilution augments IHA specificity. Tannic acid treated SRBCs combined with thermo-resistant H. parasuis antigens increases the assay resolution. Thus, our results demonstrate an improvement in the technique of H. parasuis serotyping that will prove valuable to understand Glässer's disease epidemiology and to better characterize serovars involved in outbreaks

Altered indirect hemagglutination method for easy serotyping of Haemophilus parasuis

ABSTRACT Glässer's disease is an emergent bacterial disease that affects swine husbandries worldwide causing important economic losses. The aetiological agent, Haemophilus parasuis, is currently divided in fifteen serovars but an increasing number of non-typeable serovars have been reported. Indirect hemagglutination (IHA) is indicated as a serotyping method for H. parasuis. In the present study, we describe an additional step that aims to work around a possible obstacle in the original protocol that may compromise the outcome of this assay. We observed that the choice of anticoagulant for blood collection influences and/or impairs spontaneous adsorption of H. parasuis antigens on sheep red blood cells (SRBCs). However, regardless of the anticoagulant used, chemical treatment of SRBCs with tannic acid induces a stable antigen adsorption (sensitization step). The addition of 1% BSA to SRBCs washing buffer and to antisera dilution augments IHA specificity. Tannic acid treated SRBCs combined with thermo-resistant H. parasuis antigens increases the assay resolution. Thus, our results demonstrate an improvement in the technique of H. parasuis serotyping that will prove valuable to understand Glässer's disease epidemiology and to better characterize serovars involved in outbreaks