Ochratoxin A (OTA) formation prevention is not usually available so counteracting strategies are urgent. This study investigated the toxic effects of OTA on Nile tilapia with trials to neutralize these effects by using some feed additives. Supplements used as one percent (Garlen Extra4, Nigella sativa, Garlen Extra4 plus Nigella sativa and a commercial mycotoxins binder, Fero Bind Pro) were added to 500 ppb/kg OTA-contaminated diet. Fish were fed at 3% body weight per day for 10 weeks. The clinical signs recorded in OTA – intoxicated positive control group were sluggish swimming and off food before death with reduction in survivability (53%) and growth performance. Several post-mortem lesions were in liver, kidneys and spleen. Serum levels of ALT, AST, creatinine and urea were significantly increased with reduction in total protein, albumin and globulin in ochratoxicated fish group compared to the negative control group. Concerning the pathological changes that have been noticed in ochratoxin treated fish were almost completely alleviated in examined tissues of fish that were fed on diet with Garlen Extra4 plus Nigella sativa or Nigella sativa and partially in fish that were fed on diet with Garlen Extra4 or Fero Bind Pro, respectively. Best detoxifying results were obtained by using 30 g/kg Nigella sativa plus 0.1 g/kg Garlen Extra4 followed by Nigella sativa, Garlen Extra4 then Fero Bind Pro as a commercial Mycotoxins binder. It could be concluded that inclusions of 30 g/kg Nigella sativa plus 0.1 g/kg Garlen Extra4 in Oreochromis niloticus (O. niloticus) diets could partially reduce OTA toxic effects.

In the present study, a total of 50 samples of poultry rations and drinking water in front of the birds (25 for each) were collected from various private broiler farms at Giza governorate. The collected samples were subjected to isolation and identification of contaminant fungi, screening of poultry feeds for aflatoxin B 1 residues, assessment of isolated A. flavus strains for aflatoxin production as well as molecular detection of the aflR gene in isolated A. flavus strains by polymerase chain reaction and molecular detection of the pathogenic Candida lusitaniae. The results showed 100 rations samples were highly contaminated with moulds, but were free from yeasts. The prevalence of mould and yeast from drinking water samples were 48% and 88%, respectively. The total mould count (log 10 CFU/g) obtained from poultry feed samples collected from poultry houses was higher than that of drinking water samples. Total mould count (log 10 CFU/g) in poultry feed samples ranged from 1.8 to 4.4 (log 10 cfu/g) while in drinking water samples ranged from 1 to 1.8 (log 10 cfu/ml). On the other side, it was found that the total yeast count of the examined drinking water ranged from 1.8 and 4. 2 (log 10 cfu/ml). Altogether, one hundred and three isolates representing 9 genera were recovered during this study. The most frequent fungi were from the genus Aspergillus, were A. flavus (17.9 %) appeared to be the most prevalent. The predominant candida species isolated from drinking water samples were C .lusitaniae (21.6 %), C. tropicals (16..2 %), C. pelliculosa (13.5 %), C .famata (10.8 %) and C. krusei (8.2%). Where Torulopsis spp. and Rhodotorula spp were also isolated with a prevalence of 4 (10.8%) and 7 (18.9 %).The aflatoxin B 1 residues were detected in 7 (28%) rations samples with a mean value of 43 µg/ kg. Gamma radiation cause complete inhibited germination of A. flavus spores at 9 kGy.

A total of 150 milk samples were collected from both acute and chronically infected cattle from both Giza and Minoufia governorates. Incidence of mycotic mastitis was at rate of 72% and 88%for Giza and Minoufia governorates respectively. Different mold and yeast species were isolated. The most isolated mold species from Giza samples were Aspergillus species (64.4%) followed by Geotrichum (15.2%)then Penicillium (10.2%), while in Minoufia governorate, the most isolated mold species were Penicillium at a percentage of (50.6%)followed by Aspergillus at a percentage of (40.2%). About yeast species isolation, C. parapsillosisis was the most isolated yeast species from Giza samples with percentage of 33.4%,while in Minoufia samples, C. tropicalis was the most isolated yeast species with a percentage of 22.7%. All of the isolates are identified depending on macroscopical and microscopical identification. Twelve isolated yeast strains were biochemically identified depending on rapaid yeast plus identification system, all of the tested strains were correctly identified except for C. parapsillosis strains, only 83%of the tested strains were correctly identified. Six negative examined milk samples with culture on Sabaroud dextrose agar media were subjected to Rt-PCR and Propidium mono azide stain, four of them were positive although they were negative on culture as they are considered as samples containing VBNC(Viable but non culturable) strains.