Pathogenesis of domestic pigs submitted to mycobacterial sensitizations previous to experimental infection with Mycobacterium bovis

CUERDA, MARÍA X.; COLOMBATTI, MARÍA A.; GRAVISACO, MARÍA J.; MARFIL, MARÍA J.; BARANDIARAN, SOLEDAD; SEVILLA, IKER A.; GARRIDO, JOSEBA M.; MOYANO, ROBERTO D.; ZUMÁRRAGA, MARTÍN J.; ROMANO, MARÍA I.; JUSTE, RAMÓN A.; SANTANGELO, MARÍA DE LA PAZ

Spanish Journal of Agricultural Research

INIA

Año: 2022 vol. 20

Aim of study: To demonstrate the virulence of a Mycobacterium bovis local pig isolate in order to contribute to a better understanding ofthe pathological and immunological consequences of M. bovis infection in previous sensitized animals.Area of study: Buenos Aires, ArgentinaMaterial and methods: One group of ten pigs received two oral doses of killed M. bovis suspension and a comparative intradermal tuberculin test (CIT) (multiple sensitized) and then was infected with the M. bovis strain. Another group only received the CIT (single sensitized) andthe infective dose. Humoral immune response was followed monthly, and gross pathology, histopathological and bacteriological analysis wereperformed at necropsy 100 days after infection.Main results: M. bovis oral infection induced lesions and allowed bacterial growth in most of the animals. Previous sensitization withkilled M. bovis suspension slightly raised the intensity of the response, as the multiple sensitized group showed higher lesion scores andhumoral response.Research highlights: Although the differences in lesion scores were not statistically significant, oral route infection after sensitizationcan modify the course of infections towards a fast development of lesions with a higher fibrotic component suggestive of increased resistance to infection in the right conditions.