Aspects of the immune response in sheep experimentally co-infected with Corynebacterium pseudotuberculosis and Haemonchus contortus

Abstract

The present work aimed to evaluate the possible negative regulation induced by Th2 mechanisms, unleashed by the helminth Haemonchus contortus, on the response by cells of the Th1 profile, important to contain the Corynebacterium pseudotuberculosis cocobacillus infection, in the concomitant ovine infection by these two parasites. For this, the Th1 response was evaluated in two different experimental infection conditions, using the in vitro production of interferon, which is the most typical cytokine of its profile, from cultures of peripheral blood cells of ovine animals co-infected with these two parasites, compared to their production, under the same conditions, in animals only infected with the said bacterium and using as stimulus two antigen preparations with different degrees of purity. The results evidenced a tendency of reduction in the production of this cytokine in the co-infected animals in relation to those infected with Corynebacterium pseudotuberculosis alone, in the two experimental protocols. As for the response by IgG class specific antibodies against this bacterium, evaluated by ELISA and western blot, no differences were observed between groups infected only with bacillus or with double infection.

Distribuição das subpopulações de linfócitos de caprinos experimentalmente infectados com as linhagens selvagem VD57 e atenuada T1 de Corynebacterium pseudotuberculosis em resposta aos antígenos secretados (TPP E MQD) da linhagem atenuada

“…Estudos feitos em modelo murino sugerem que células T desempenham importante papel no desenvolvimento do granuloma em infecções por micobactérias (Saunders et al, 1998;Tanaka et al, 2005;Buza et al, 2009;Rodrigues et al, 2018).…”

Influence of Iron Chelating Agents on the in Vitro Growth Curve of Corynebacterium pseudotuberculosis Strains

“…The disease has a chronic nature, being responsible for negative impacts on weight gain and milk production, as well as the leather devaluation and carcasses condemnation in small ruminant slaughterhouses. In addition to antibiotic treatment being considered unfeasible, its eradication is difficult, as it is widely disseminated in herds worldwide (DORELLA et al, 2006) and so far, no satisfactory vaccine model has been produced for goats and sheeps (BASTOS et al, 2012;RODRIGUES et al, 2018, SÁ et al, 2021.…”