Drug resistance patterns and susceptibility to aflatoxin B1 of strains of Escherichia coli and Staphylococcus aureus.

The antibacterial properties of aflatoxin B1 have been evaluated against antibiotic-resistant clinical isolates of Escherichia coli and Staphylococcus aureus. The inhibition of growth ranged from 11.5 to 60.0% and 4.5 to 18.5% in the strains of S. aureus and E. coli, depending on the extent of drug resistance. Aflatoxin-B1 binding varied with toxin concentration, the presence of surfactants (Tween-80 or EDTA) as well as with the antibiotic-resistance pattern; binding was maximal in antibiotic-sensitive strains and least in the most resistant strains. Binding of aflatoxin B1, correlated with growth inhibition. Aflatoxin B1 also caused leakage of cell contents and decrease in inulin uptake, effects which were also concentration dependent.