Aflatoxigenic fungi and co-occurrence of mycotoxins in poultry feeds from Entre Ríos, Argentina.

MONGE M.P.,; MAGNOLI C.E,; CHIACCHIERA S.M.

Mendoza

Congreso; Mycored- Argentina. Strategies to rteduce the impact of mycotoxins in Latin America in a global contex.,; 2011

Universidad Nacional de Río Cuarto

Argentina poultry production has been growing heavily in the past few years and there is perspective to continue to do so in the near future. Corn grains and soybeans are the main ingredients in feeds. These grains are colonized by mycotoxigenics species belonging to the genera Aspergillus and Fusarium. The aims of the present work were: i) to determine the mycobiota in poultry feeds and the ability to produce aflatoxin B1 (AFB1) by A. flavus and A. parasiticus strains; and ii) to evaluate the natural co-occurrence of aflatoxins (AFs), fumonisin (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 and T-2 toxin in poultry feeds by LC-MS/MS. A total of 57 samples of pelleted poultry feed (10 started “1” (S1), 10 started “2” (S2), 10 started “3” (S3), 10 finished (F), 3 finished off (FO), 1 finished split (FP), 4 finished parallel half (FPH) and 9 finished half (FH) were collected during 2010 year from an avian plant located in Entre Ríos, Argentina. Quantitative enumeration of fungal propagules was done on dichloran rose bengal chloranphenicol agar (DRBC) and dichloran 18% glycerol agar (DG18). Total fungal count results showed that all poultry feed samples not exceeded the maximum limit established (1 x 104 CFU g-1). Aspergillus flavus and A. parasiticus were the only species isolated belonging to Flavi section. From these strains 25% were AFs producers. Eleven and fourteen percent of A. flavus and A. parasiticus strains produced AFB1 (mean levels ranged from 0.8 to 2.0 µg g-1). Fusarium species producers of trichothecenes and FBs were not detect in any of the samples. All samples were contaminated with FB1, T-2 and HT-2 with levels ranging from 4131.0 to 6125.0, 7.23 to 18.9, 19.3 to 38.7 μg kg-1, respectively. Aflatoxin B1 was only detected in starter 1, 2 and 3 and in finished feed in levels which varied from 1.38 to 8.5 μg kg-1; while gliotoxin and DAS were not detected at all. Co-occurrence of one or more mycotoxins was detected in 60% of samples: FB1,HT-2 and T-2 toxins was found in 82% of samples, HT-2 and T-2 toxin in 8%, AFB1, FB1, H-T2 and T-2 toxin in 6%; and AFB1, FB1 and T-2 toxin in 3%. None of samples exceeded the maximum tolerable limit (20 mg kg-1 FB1 plus FB2) established for avian feeds by the European Commission. Something similar occurs with AFs (Mercosur: 20 and EU: 10 μg kg-1) and with HT-2 and T-2 toxin (both limits established by EU in 50 μg kg-1). Therefore it should be emphasized that although individual levels are below the established security limits naturally co-occurrence of multiple toxins might exaggerate the toxicity symptoms and the potential risk of mycotoxicoses.