Enumeration and identification of Aspergillus group and Penicillium species in poultry feeds from Argentina.

A total of 180 samples of poultry feeds were collected during 1996 and 1997 from different factories in the south of the province of Córdoba-Argentina. They were examined for the occurrence of Penicillium spp. and Aspergillus group species. Likewise, the capacity to produce aflatoxins by the Aspergillus section flavi group was determined. The predominant species of Aspergillus were A. flavus and A. parasiticus. For Penicillium spp., P. brevicompactum, P. purpurogenum and P. oxalicum were identified. Less frequently isolated were A. candidus, A. fumigatus, A. niger, A. orizae, A. parvulus, A. tamarii, A. terreus, and P. expansum, P. funiculosum, P. minioluteum, P. pinophylum, P. restrictum, P. variable and others. The mean value counts ranged from 1 x 10(3) to 9.5 x 10(4) CFU/g for the Aspergillus spp. and from 1.2 x 10(3) to 2.5 x 10(5) CFU/g for the Penicillium spp. When cultured on autoclaved rice kernels for 1 week in the dark at 25 degrees C, mycotoxin production by strains of A. flavus was as follows: 21 of the 45 assayed strains (47%) produced aflatoxins. From them, 24% of the isolates produced AFB1 and AFB2 with levels from 181 to 14545 and 6 to 3640 micrograms/kg respectively. Only 10 strains produced AFB1 with levels from 10 to 920 micrograms/kg. Fifty percent of the A. parasiticus strain was toxicogenic; six aflatoxicogenic profiles were identified. Only 10% of the strains produced all of the aflatoxins. These results showed that a potential exists for the production of mycotoxins by the Aspergillus section flavi and the Penicillium spp. They also suggested an association of mycotoxicosis with poultry feeds in Argentina.