Histopathology of the small intestine of rats and mice experimentally infected with cynodiplostomum azimi [trematoda]

A histopathological study was performed on the intestine of rats and mice experimentally infected with C. azimi at different periods [one, four and eight weeks]. In both rats and mice, worm sections showed full maturity at the end of the first week infection. The intestinal lesions were limited to the duodenum of the infected rats and mice. The most prominent pathological changes were found at the mucosa, especially the villi. After one week of infection the mucosal pathology was chiefly villous atrophy [thickening, blunting of tips and fusion] with stromal infiltration, then these lesions increased as the infection period increased. After four weeks of infection, villous atrophy was accompanied with compression, erosion and pyknosis of villous epithelia, reduction of goblet cells, cellular infiltration and pronounced edematous villous stroma. At eight weeks, crypts hyperplasia, cellular infiltration and fibrosis were also seen

Some ultrastructrual studies on the excretory bladder of the adult cynodiplostomum azimi [trematoda: digenea] in infected rats

Transmission electron microscope was used to reveal the reserve bladder system of the adult Cynodiplostomum azimi in experimentally infected rats. It was shown that this system consisted of a number of lacunae. The lacunar lining appeared as syncytial epithelium containing many nuclei, mitochondria, dense secretory bodies, Golgi complex and bundles of smooth muscles. The outer surface of the excretory epithelium was highly folded and lamellated. These lamellae were continuous with the excretory epithelium. Small lipid droplets were observed within the excretory epithelium, while larger ones were associated with the lamellae. The large lipid droplets were released in the lacunal lumen after the rupture of the lamellae surrounding them

Scanning electron microscopy of the small intestine of rats experimentally infected with cynodiplostomum azimi

Scanning electron micrographs of the proximal intestine of rats infected with C. azimi showed mild villous changes and excessive mucus secretion as early as the first day after infection. On the second day, the regular leak-like pattern of the villi was not seen, the epithelial lining of the mucosa was damaged with large amounts of mucus. Goblet cell openings appeared either empty or filled with secretions. The mucosal damage persisted for three months. Four months after infection, villi regained part of their normal pattern. Their epithelial lining although less damaged, appeared delicate. Villi away from the worm were less affected. Pathological changes at different intervals of infection were discussed in relation to the surface structure of the parasite