ارزیابی آفلاتوکسین ها و عوامل مولده آنها در نانهای قابل تغذیه در دام

Objectives: 1) Comparative investigation of normal, partially infected and moldy breads to aflatoxin and their causative agents, 2) Determination of amounts and types of aflatoxin and Aspergillus spp 3) Determination of total fungal counts in either breads containing aflatoxin or without aflatoxin, 4) Correlations between aflatoxin, Aspergillus and total fungal count.
Design: Observational study.
Procedure: 222 bread samples which consumed as ruminants foodstuffs were collected from bread shops in urmia during 2001¬2002. The number of normal, partially infected and moldy breads were 54, 56 and 112, respectively. Aflatoxins (AF) were assessed by Thin Layer Chromatography Methed using standard aflatoxins B 1, B2, G 1, G2. Breads were cultured for Aspergillus spp using Saboroud Dextrose Agar Media and total fungal counts were calculated using dilution and culture method.
Statistical analysis: Chi-square test and correlations coefficient.
Results: Aflatoxin was found in 42 (18.17%) breads in which 4 had 2 types of aflatoxin (1.8%) and in one bread 3 (0.5%) and another 4 types of aflatoxin (0.5%). Distribution and percent of aflatoxin B 1, aflatoxin B2, aflatoxin Gland aflatoxin G2 were 16 (36.67%.), 18 (42.87%), 7 (16.6%) and 10 (247%), respectively.
10 of 42 breads had aflatoxin B10ver 20 ppm (4.5%),8 had 10-19 ppm (3.6%) and 24 had less then 10 ppm (10.8%). The percentage of aflatoxin contamination in normal, partially infected and moldy bread were 5.5%, 10.9% and 32.4%., respectively, which were significantly different (P<0.05). The results of fungal culture showed 94.1 % (80/85) infected to A. fumigatus (50 cases), A. niger (56 cases) andA.jlavus (2 cases). 53 cases (63.357%) hadA .fumigatus or A. niger, 26 cases (31.18%) showed two types of Aspergillus and one case had all three Aspergilluses. 10 of 80 cases were diagnosed in apparently nonnal and partially infected bread while 70 cases were in moldy breads. Aflatoxins were found in 42 of 85 cultured cases while 43 cases had no aflatoxins. Also 38 samples showed either aflatoxin, Aspergillus or total fungal count while in 41 cases instead of positive total fungal count and Aspergllus, no aflatoxin was detected. Total fungal count varied from 1 to 450000 fungi colony per gram bread. Positive correlations were found between aflatoxin and fungal count (r = 0.44), aflatoxin and A. niger (r = 0.58), aflatoxin and A. fumigatus (r = 0.85), total fungal count and (r = 0.90), total fungal count and (r = 0.70).
Clinical implications: It is concluded that 1) aflatoxins produced by Aspergillus in normal and moldy breads could be an important as ruminant foodstuffs, 2) aflatoxin Bl with over 20 ppm was found as a main aflatoxin in breads, 3) A.fumigatus,A. niger andA.flavus were the main Aspergillus strains in urmia, and finally 4) It is recommended to modify the collecting and consumption methods
of bread as ruminant foodstuffs to minimize the transmission of aflatoxin to ruminants and human as well. J. Fae. Vet. Med. Univ. Tehran. 58, 4:347-351, 2003.