ZOONOTIC SIGNIFICANCE OF SOME AETIOLOGICAL AGENTS ISOLATED FROM FISH

One hundred and forty freshwater fish samples 55 from Oreochromis niloticus (Tilapia nilotica or Bolti), 45 from Mugil cephalus (Bouri) and 40 from Clarias lazera (Armout catfish), were collected from various markets and shops at Dakahlia and Gharbia Provinces. Skin, gills, intestine and muscles from each sample were examined for the presence of some pathogenic and potentially pathogenic bacteria and fungi of public health importance. The most predominant bacterial isolates from Orechromis niloticus, Mugil cephalus and Clarias  lazera respectively were: E.coli (8.8%, 9.0% and 10.4%), Salmonella spp. (1.7%, 0.0% and 1.8%), Proteus spp. (38.5%, 18.1% and 39.8%), Klebsiella pneumoniae (13.8%, 14.7% and 13.4%), Citrobacter freundi (0.0%, 10.9% and 0.0%), Enterobacter spp. (14.3%, 2.8% and 6.3%), Shigella flexneri type 6 (8.0%, 11.9% and 9.3%), Pseudomonas spp. (6.9%, 7.1% and 9.7%), Staphylococcus spp. (34.6%, 26.5% and 36.9%) and Streptococcus spp. ( 65.4%, 73.5%, and 63.1%). Meanwhile, the predominant fungi isolated from the examined Bolti, Bouri and Armout catfish were: Aspergillus spp. (51.5%, 66.6% and 65.0%), Penicillium spp. (17.2%, 5.7% and 10.0%), Mucor spp. (15.8%, 22.0%, and 20.8%), Rhizopus spp. (3.9%, 5.7% and 4.2%), Rhodotorulla mucolignosa (15.9%, 16.7% and 11.3%), Torulopsis spp. (21.8%, 22.25 and 15.5%) and Candida spp. (62.3%, 61.1% and 73.2%), respectively. The zoonotic importance of these isolates was discussed.