58 research outputs found

    Experimental Contagious Caprine Pleuropneumonia: A Long Term Study on the Course of Infection and Pathology in a Flock of Goats Infected with Mycoplasma capricolum subsp. capripneumoniae

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    Contagious caprine pleuropneumonia (CCPP) is a major threat to goat farming in parts of Africa and Asia. It classically causes acute high morbidity and mortality early in infection, but little is known of its long term epizootiology and course. In this study, 10 goats were inoculated with Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae) and then mixed with 15 goats for contact transmission. The disease course was monitored in each goat for 56–105 days, whereafter the goats were killed and necropsied. Varying features signifying infection occurred in altogether 17 goats (7 inoculated, 10 in-contact). Clinical signs were severe in 8 goats but no fatalities occurred. Only 6 goats had serum antibody titres against M. capripneumoniae in ELISA. Fourteen goats (5 inoculated, 9 in-contact) had chronic pleuropulmonary lesions compatible with CCPP at necropsy and 7 of those showed M. capripneumoniae antigen in the lung by immunohistochemistry. Neither cultivation nor PCR tests were positive for the agent in any goat. The results indicate that the clinical course of CCPP in a flock may be comparatively mild, M. capripneumoniae-associated lung lesions may be present at a late stage of infection, and chronic infection may occur without a significant serological response

    Free exopolysaccharide from Mycoplasma mycoides subsp. mycoides possesses anti-inflammatory properties

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    In this study we explored the immunomodulatory properties of highly purified free galactan, the soluble exopolysaccharide secreted by Mycoplasma mycoides subsp. mycoides (Mmm). Galactan was shown to bind to TLR2 but not TLR4 using HEK293 reporter cells and to induce the production of the anti-inflammatory cytokine IL-10 in bovine macrophages, whereas low IL-12p40 and no TNF-α, both pro-inflammatory cytokines, were induced in these cells. In addition, pre-treatment of macrophages with galactan substantially reduced lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines TNF- and IL-12p40 while increasing LPS-induced secretion of immunosuppressive IL-10. Also, galactan did not activate naïve lymphocytes and induced only low production of the Th1 cytokine IFN-γ in Mmm-experienced lymphocytes. Finally, galactan triggered weak recall proliferation of CD4+ T lymphocytes from contagious bovine pleuropneumonia-infected animals despite having a positive effect on the expression of co-stimulatory molecules on macrophages. All together, these results suggest that galactan possesses anti-inflammatory properties and potentially provides Mmm with a mechanism to evade host innate and adaptive cell-mediated immune responses. (Résumé d'auteur

    Immune responses in cattle vaccinated against contagious bovine pleuropneumonia: preliminary results

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    Contagious bovine pleuropneumonia (CBPP) is one of the most important transboundary animal diseases in Africa. In recent years, CBPP has been found in countries like Botswana from where it was previously eradicated (Amanfu et al., 1998). There is growing evidence to indicate that the incidence of the disease is increasing in endemic areas. These recent increases can be attributed to uncontrolled movement of cattle, poor disease control strategies and application of sub-standard vaccines (FAO, 2000; Masiga, 1996). There is sufficient consensus that efficacious vaccines could contribute substantially to an integrated control program for CBPP (Anonymous, 2000; Tuslane et al., 1996). This would involve improvement of existing and Development of a new generation of vaccines. This study is aimed at investigating the immunogenicity and efficacy of two different vaccines against CBPP. The T1 44 vaccine strain and a saponin formulated inactivated virulent strain of Mycoplasma mycoides subspecies mycoides small colony (Mmm SC), strain 237, were used

    Experimental inoculation of goats with the contagious bovine pleuropneumonia

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    The objective of the trial was to determine the susceptibility of goats to the contagious bovine pleuropneumonia (CBPP) agent. Four inoculation routes – subcutaneous, endobronchial, intrapleural and intraperitoneal – were tested. One of the goats infected intraperitoneally died of peritonitis. The CBPP agent was isolated again from the ascitic fluid. The serological tests, competition ELISA in particular, revealed the occurrence of serological conversions in a number of animals. This should pave the way to further field studies to determine if goats in contact with CBPP-affected bovines may be naturally contaminated

    Diagnosis and control of contagious caprine pleuropneumonia

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    Le diagnostic de la pleuropneumonie contagieuse caprine a souvent été jugé difficile, cette maladie pouvant être confondue avec d'autres mycoplasmoses des petits ruminants. Les symptômes et lésions peuvent être similaires et l'isolement de Mycoplasma capricolum subsp. capripneumoniae (MccF38) nécessite une bonne compétence technique. Une fois les souches MccF38 isolées, leur identification ne devrait pas poser de problème. De nouvelles techniques, telles que l'amplification en chaîne par polymerase, offrent désormais la possibilité d'identifier MccF38 directement à partir de prélèvements lyophilisés. Toutefois, l'isolement de souches MccF38 reste obligatoire pour une déclaration officielle d'infection. Jusqu'à présent, le test sérologique de référence était l'épreuve de fixation du complément, ses principaux inconvénients étant l'absence de sensibilité et de spécificité, ainsi que la brève persistance des anticorps décelés au moyen de cette technique. L'épreuve immuno-enzymatique (enzyme-linked immunosorbent assay : ELISA) de compétition, récemment mise au point, devrait désormais permettre de déterminer, à l'occasion de larges enquêtes sérologiques, la prévalence réelle de la maladie. Les traitements antibiotiques sont efficaces, mais ils ne peuvent prévenir la persistance d'un portage latent du mycoplasme. Unvaccin à mycoplasmes tués, adjuvé à la saponine, a été mis au poins au Kenya : il confère aux caprins une immunité d'environ un an. (Résumé d'auteur
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