Clinical course and pathogenicity of a Mycobacterium avium subsp. paratuberculosis isolate from scimitar oryx (Oryx dammah) in experimentally infected rabbits

Abstract

Aim of study: To evaluate the infectivity of a MAP type C of a scimitar oryx (Oryx dammah) - included in an international conservation list - that showed clinical signs and granulomatous enteritis associated with paratuberculosis in rabbits (Oryctolagus cuniculus) using molecular, bacteriological and pathological methodologies. Area of study: The study was made in Tequisquiapan, Queretaro, CEIEPAA, FMVZ, UNAM, Mexico. Material and methods: Three 6-week-old female New Zealand rabbits were orally infected for 3 consecutive days with 109 CFU of the MAP isolate. Blood and fecal samples were collected every 2 weeks for a total period of 28 weeks. IS900 PCR in blood and F57 real-time PCR in the feces were performed every 2 weeks and pathological analysis and bacteriological culture from tissue were made 28 weeks post infection. Main results: MAP was detected by IS900 PCR in the blood of two of the three animals after 2 weeks of infection and again by F57 real-time PCR in the feces of the three infected rabbits. Infection with the MAP isolates in feces at 22 and 28 weeks post infection in one rabbit and isolate of vermiform appendix resulted in the development of granulomatous lesions in the three rabbits. The lesions were diffuse intermediate in one animal and multifocal in the other two rabbits. Research highlights: Overall, these results demonstrated the infectivity of a MAP isolate from the scimitar oryx in rabbits.

Keywords

• bacteriological culture
• granulomatous lesions
• IS900 PCR
• real-time F57 PCR
• ruminants
• experimental infection