THE PATHOLOGICAL EFFECT OF PEPTIDOGLYCAN ON RATS’ LUNGS PART TWO: NON PATHOGENIC BACTERIA BACILLUS SUBTILIS

Abstract

Fourteen isolates of Bacillus were obtained from twenty samples isolated from soil. Three of which were identified as B. subtilis by biochemical tests. For extraction of peptidoglycan from B. subtilis, mechanical disintegration by glass beads and vortex plus enzymatic digestion by DNase, RNase and pronase were applied. The partial purified peptidoglycan showed four protein bands compared with crude peptidoglycan which showed several bands when it performed in polyacrylamide gel electrophoresis under undenaturing conditions.The histopathological changes for the injected group of rats with the germ suspension of B. subtilis were increased number of alveolar macrophages, thickening of alveoli walls in addition to accumulation of fluids (edema) inside the lung tissue. Whereas the peptidoglycan injected group revealed heamorrhage, edema formation, vacuolation, increased number of lymphocytes, precipitation of collagen fibers, and rupture of alveoli walls and sloughing of epithelial cells inside bronchioles lumen.The effects of histopathological changes caused by peptidoglycan were more severe than those of cell suspension, which suggesting the important role of this polymer in the pathogensis of this bacteria.