الفهرس | Only 14 pages are availabe for public view |
Abstract This study was carried out on 360 freshwater fishes (240 Oreochromis species and 120 Clarias gariepinus). They were collected from Kafr El-Shikh, Sharkia, and Giza governorates and during different seasons. Naturally infected fishes showed clinical abnormalities such as skin darkening, exophthalmia, corneal opacity, abdominal distention, ulceration of the skin and cotton wool like growths on various parts of the body. Fishes were then subjected to post mortem examination which revealed many abnormalities. Mycological examination revealed the isolation of 2081 fungal isolates from 150 diseased and 210 apparently healthy fish samples (1658 mould and 423 yeast isolates), of which 1334 were isolated from Oreochromis species and 747 isolates from Clarias gariepinus. Isolated moulds belonged to the following genera: Saprolegnia (4.2%), Aspergillus (43.0%), Fusarium (14.1 %), Mucor (14), Penicillium (17.2), Rhizopus . (4.8%), Scopulariopsis (1.2%), Paeciliomyces (1%) and Curvularia (0.4%). Yeasts isolated also from both fish species had the following incidence: Candida albicans (35.9 %), other Candida species (19.1%), Rhodotorula species (31.4%) and Torulopsis species (13.5%). Experimental infection with the most predominant fungi (Aspergillus flavus, Fusarium species and Candida albicans) was conducted to evaluate the pathogenicity of these isolates. Clinical pictures of experimentally infected fish were similar to those of natural infection. Inoculated fungi were re- isolated from different organs. Results were confirmed with histopathological examination, which revealed the presence of fungal hyphae and spores in different organs. |