ANFS332 Lecture Notes - Lecture 10: Mycobacterium Avium Subspecies Paratuberculosis, Paratuberculosis, Dairy Cattle

• School: University of Delaware
• Department: Animal and Food Sciences
• Course: ANFS332
• Professor: Keeler Jr.Calvin

Document Summary

Joh(cid:374)e"s disease: contagious bacterial disease of the intestinal tract of cows, first described in a dairy cow in 1895 (dr. h. a. Johne dresden, germany: most commonly seen in dairy cattle but also observed in other ruminants (sheep, goats, deer, antelope, bison) Mycobacterium: gram positive, small (1. 5 micrometers), slightly curved rods, aerobic, non-motile, non-spore forming, high lipid component in cell walls (cid:373)ake the(cid:373) (cid:862)acid fast(cid:863) (spe(cid:272)ifi(cid:272) stai(cid:374)i(cid:374)g method) It (cid:272)a(cid:374)"t t(cid:396)a(cid:374)spo(cid:396)t i(cid:396)o(cid:374) so it (cid:374)eeds to (cid:862)steal(cid:863) iro(cid:374) fro(cid:373) other cells (needs mycobactin (cid:271)ut does(cid:374)"t ha(cid:448)e a(cid:374)y) It not only survives attack by macrophages, this bacteria replicates inside macrophages. M. paratuberculosis vs. m. avium: m. paratuberculosis bacteria are not thought to be free-living (able to grow and multiply) in the environment. This means infected animals are the only place in nature where growth and multiplication of m. paratuberculosis can occur. Certain acidic soil types, notably peat bogs, contain higher than average numbers of m. avium.