Fasciola gigantica: parasitological and scanning electron microscopy study of the in vitro effects of ivermectin and/or artemethea

To evaluate the in vitro effects of different, concentrations of ivermectin and/or arteinether on Fasciola giganfica worms and to study the parasitological changes and tegumental alterations using scanning electron microscopy [SEM]. F. giganhica worms were incubated in vitro for 24 and 48 hrs with 3 concentrations of either ivermectin 01. artemether [10, 20 and 50 micro g/ml] or both in half the concentration of either of them [5, 10 and 25 micro g/ml]. Exposure of Fasciola worms to 25+25 micro g/ml of combined drug regimens or to 50 micro g/ml of either ivermectin or artemether for 48 hrs led to 100%, 41.7% and 75% worm killing which were accompanied by a significant reduction in egg laying capacity and significant increase in dead eggs which were maximally recorded in combined drug regimens. SEM of the flukes incubated for 48 hrs with combined drug regimens showed maximal tegumental disruption with swelling of the worm body, roughness, blebbing, sloughing and complete loss of spines. Disruption to the tegument of the flukes induced by artemether was more than that of ivermectin. Artemether alone or combined with ivermectin in half doses had potent fasciocidal activities. Besides, half doses of combined drug regimens had higher ovicidal effects than each drug alone, in vivo studies are recommended to furtherly explore the efficacy of combined regimens against Fasciola infection

Scanning eleectron micropical studies on cercaria and metacercariae of fasciola gigantica

The surface topography of Fasciola gigantica cercariae and metacercariae was studied by scanning electron microscopy. The head of F. gigantica cercaria is covered with several small knobs and its tail is provided with two lateral folds, fused ventrally, near the distal end of the tail. The oral sucker is smaller than the ventral one and possesses a characteristic surface structure. The outermost layer [layer I] of the outer cyst wall of the metacercaria is roughened with irregular furrows. The inner surface of the outer cyst wall [layer II] is more homogeneous and nearly smooth. The outermost layer of the inner cyst wall [layer III] is smooth and lacks any furrows or tubercles. The differences between F. gigantica and F. hepatica cercariae and metacercariae were discussed