Mycotoxigenic potentials of the genera: Aspergillus, Fusarium and Penicillium isolated from houseflies (Musca domestica L.)

A study on the potential of houseflies (Musca domestica L.) to spread fungal spores in Gauteng Province, South Africa proved that houseflies are vectors for fungal spores. Therefore, there is a need to determine the toxigenic potentials and to identify the mycotoxins produced by fungal isolates derived from this study. In total 377 potentially toxigenic isolates of Aspergillus (186), Fusarium (85) and Penicillium (106) species (spp.) were isolated. These isolates were further tested for their ability to produce aflatoxins (AFs) [aflatoxin B₁, B₂, G₁ and G₂], deoxynivalenol (DON), fumonisin B₁ (FB₁) ochratoxin A (OTA), and zearalenone (ZEA) by high-performance liquid chromatography (HPLC) respectively. Strains of A. flavus and A. parasiticus belonging to the genera of Aspergillus were found to be the main producers of AFB₁, AFB₂, AFG₁, and AFG₂, while A. carbonarius, A. niger and A. ochraceus produced OTA. Fumonisin B₁ was produced by F. verticillioides and F. proliferatum with concentrations ranging from 20 to 1834 μg/kg and 79 to 262 μg/kg respectively. Deoxynivalenol produced mainly by F. culmorum (2–6 μg/kg), F. graminearum (1–4 μg/kg), F. poae (1–3 μg/kg), and F. sporotrichioides (2–3 μg/kg) species was the least detected toxin in this study. The high mycotoxins levels produced in isolates from houseflies in this study are regarded as unsafe, especially when international legislated tolerance levels for mycotoxins are considered. Thus, possible human exposure to mycotoxins may pose concerns with respect to human health and demands constant and consistent investigation.