Comparative morphological studies on three sarcocystis species in Sohag, Egypt

Samples from the tongue, heart, oesophageal and skeletal muscles were collected from 100 cow and 100 buffalo from Sohag slaughterhouses. Macroscopic examination for sarcocysts was followed by microscopic ones on impression smears and compressed muscles. Histological sections and transmission electron microscope [TEM] studies were done on positive cases. Sarcocystis infection rate of cows were 84%. Two species of Sarcocystis were detected: 1-S. cruzi with a membrane provided with hairlike villar protrusions folded over the surface of the cyst. These protrusions were rod-like, round, oval or irregular in shape and were approximately parallel to the cyst surface. 2-S. hominis characterized by a cyst wall consisting of cylindrical finger-like villar protrusions and having microfilaments. The protrusions were perpendicular on the cyst surface with broad tips and contain microfilaments. Buffaloes' muscle, samples revealed an infection rate of 28%. The macroscopic fusiform-shaped species only was detected [Sarcocystis fusiformis]. The role of cyst wall ultrastructure and thickness were discussed regarding identification and pathogenicity

Scanning Electron Microscopy studies on Wohlfahrtia nuba [myiasis producing fly] larvae

Using SEM techniques, micromorphological features of the three larval instars of Wohlfahrtia nuba were studied, revealing their anterior ends, anterior spiracles, and posterior ends and posterior spiracles. We illustrated some important differences especially in shape and size of the mouth hooks, size, number and shape of the leaf-like structures surrounding the mouth vestibule and the blunt broad branches of the lower end of the frontal sclerites. Also, this work illustrates the process of first larval moulting, which occurs through a longitudinal line starting from the anterior end of the larva till reaching its posterior end. Characteristic morphological differences were illustrated between the three larval instars as well. Thus it seems that it is of much importance to use SEM in the study of the larval stages of myiasis-producing flies and not only in the third stage