Natural occurrence of Fusarium species and fumonisin-production by toxigenic strains isolated from poultry feeds in Argentina.

Fusarium species and fumonisin production by toxigenic strains were investigated. During 1996-1998, 158 samples of poultry feeds were collected from a factory located in the department of Rio Cuarto Córdoba province, Argentina. The most common species of Fusarium were F. moniliforme (60.7%) and F. nygamai (35.4%) followed by F. semitectum, F. subglutinans, F. proliferatum, F. dlamini, F. solani, F. oxysporum and F. napiforme. Fungal counts ranged from 1 x 10(3) to 8 x 10(5) CFU/g with mean values from 1.5 x 10(3) to 2.3 x 10(5) CFU/g. The highest counts were for F. dlamini, F. subglutinans, F. moniliforme and F. nygamai. Strains of F. moniliforme, F. nygamai, and E. proliferatum were screened for their potential to produce fumonisin B1 (FB1), fumonisin B2 (FB2) and fumonisin B3 (FB3) in corn grain. The samples were analysed using a modified high performance liquid chromatography method. The strains assayed, 43 strains, produced three fumonisins. There was a high degree of variability in the quantities of FB1, FB2, and FB3 produced. The toxin produced in highest levels by the majority of the strains was FB1. The range of concentration varied from 5.4 to 3,991, 1.01 to 189 and 0.4 to 765 ppm per gram of corn for FB1, FB2 and FB3 respectively. The toxigenic pattern of strains was normal, although two strains of F. moniliforme produced exceptionally high concentrations of FB3 and minor concentrations of FB2 and FB1. This is the first report from Argentina on Fusarium species in poultry feeds and fumonisin production by these strains.