Cryptosporidium and other zoonotic parasites in Oreochromis niloticus in Assiut governorate [electronic resource].

Includes references.

This study was carried out on 120 Oreochromis niloticus fish (60 wild and 60 cultured). The fish were randomly collected, from different areas of Assiut Governorate as well as from some fish farms. They were used to investigate the prevalence of Cryptosporidium and other zoonotic parasites in O. niloticus. Examination of gills, muscles and the contents of the gastrointestinal tract revealed highest parasitic infestation rate (80 %) in wild compared to (55 %) in cultured O. niloticus. The prevalence of the isolated parasites in wild and cultured O. niloticus was as follows: Cryptosporidium spp. 15.0 % and 23.3% respectively; Acanthocephela (Acanthocentius tilapae) 8.3 % and 9.2% respectively; microscopic encysted metacercariae 88.3% and 26.7 % respectively while macroscopic encysted metacercariae detected only in wild O. niloticus 40%. Killing factors (temperatures, solutions and processing methods) were studied on encysted metacercariae (EMC) in O. niloticus killing criteria followed the movability index (MI) from 1.000 within 24 hours. Muscle pieces containing viable EMC were incubated in different concentrations of NaCl, acetic acid or commercial vinegar at room temperature.

Summary in Arabic.