MYCOBACTERIUM-AVIUM INFECTION OF GUT MUCOSA IN MICE ASSOCIATED WITH LATE INFLAMMATORY RESPONSE AND INTESTINAL-CELL NECROSIS

Mycobacterium avium is an intracellular pathogen that is associated wi th disseminated infection in acquired immunodeficiency syndrome (AIDS) , Patients with AIDS appear to acquire M, avium mainly through the gas trointestinal tract. Previous studies have shown that healthy mice giv en M, avium orally develop disseminated infection after 2-4 weeks. The chief site of M, avium invasion of the intestinal mucosa is the termi nal ileum, To learn more about the pathophysiology of M, avium infecti on of the intestinal mucosa, C57BL/6 bg+ bg+ mice were infected orally with M, avium strain 101 and groups of six mice were killed each week for 8 weeks. The terminal ileum was then prepared for histopathologic al studies and electron microscopy, A delayed inflammatory response wa s observed and influx of neutrophils in the Peyer's patches was the on ly abnormality seen at 1 week. A severe inflammatory response was seen from week 2 to week 5 and necrosis of intestinal villi was observed 6 weeks after infection. These results indicate that invasion and infec tion of the normal intestine by M, avium results in a severe inflammat ory response with segmental necrosis of the intestinal mucosa.