Screening of Mycobacterium avium subsp. paratuberculosis strains virulence in macrophages and mouse models

MARÍA ALEJANDRA COLOMBATTI OLIVIERI; ROBERTO DAMIÁN MOYANO; GABRIEL EDUARDO TRAVERIA, MARÍA LAURA MON; MARIANA NOELIA VIALE; BELÉN ROCÍO IMPERIALE; FERNANDO DELGADO; MARÍA DE LA PAZ SANTANGELO AND MARÍA ISABEL ROMANO

BRAZILIAN JOURNAL OF MICROBIOLOGY

SOC BRASILEIRA MICROBIOLOGIA

Año: 2016

1517-8382

Paratuberculosis is a chronic disease caused by Mycobacterium avium subsp. paratuberculosis (Map) that mainly affects ruminants. This disease produces serious economic losses and therefore its control and the development of an effective vaccine are essential. To find a better vaccine candidate, we examined six local isolates in the murine macrophage cell line J774. None of the strains showed an effective multiplication rate in J774 but some of them differed in the survival curve. Therefore, we selected the four strains with lower survival rate (1543/481, A162, 1347/498 and 6611) to be evaluated in Balb/c mice. In this model, 1543/481 and A162 displayed an attenuated phenotype, whereas 1347/498 and 6611 multiplied in the infected animals. The animals inoculated with the less virulent strain (1543/481 and A162) had lower production of proinflammatory cytokines and antibodies compared to the most virulent strains (1347/498 and 6611). In particular one of the most virulent strain, 6611, had a Th1 response with production of IFNg and a marginally increment in IL-17. We selected this strain (6611) to be proved like an inactivated vaccine candidate and the less virulent strain 1543/481 like a live vaccine candidate in future experiments