Mycotoxic flora and mycotoxins in smoke-dried fish from Sierra Leone.

Examination of 20 samples of smoke-dried fish of the Ethmolosa sp. commonly called "Bonga", from homes and markets in Njala (Sierra Leone) revealed the presence of 4 Aspergilli species: A. flavus Links ex Fries, A. ochraceus Wilhelm, A. tamarii Kita and A. niger van Tieghem. Fresh or properly preserved smoke-dried fish showed no signs of fungal contamination. Mouldy fish extracts contained varying amounts of aflatoxins B1, G1, G2 and ochratoxin A. Isolates of A. flavus grown on yeast extract sucrose (YES) medium, produced considerable amounts of aflatoxin B1 and G1 and trace amounts of G2. On YES medium A. ochraceus produced large amounts of ochratoxin A but no penicillic acid.