Detection of zearalenone mycotoxin and characterization of fusarium species in commercial maize grains from Northern Ghana

The fungal genus Fusarium contains many important plant pathogens as well as endophytes of wild and crop plants. Together with their derivative mycotoxins such as zearalenone, can inhibit eukaryotic protein synthesis and cause toxicosis in humans and animals as well exhibit antimicrobial and phytotoxic activities. Maize (Zea mays L.) is among the major cereal staples in Africa including Ghana, but it is highly susceptible to Fusarium infestation. The focus of this study was to measure the level of zearalenone (ZEA) in commercial maize from northern Ghana, to assess traders' knowledge and awareness of mycotoxins and isolates and to characterize Fusarium species (ZEA producing ones). A total of 75 maize samples were randomly purchased from 11 different market centres in northern Ghana. ZEA levels were determined using HPLC. Knowledge and awareness of mycotoxin among traders were assessed using face-to-face interviews. Fusarium species were isolated using selective media and PDA growth media and molecularly characterized using species-specific primers. ZEA was found in 33.3 % of the samples (25/75), although generally at low levels, 0.61 to 3.05 ng/g with a mean concentration of positive samples of 1.50 ng/g. More than half (53.7%, n=22) of the traders have no knowledge of mycotoxins contamination of maize grain. Among those who were aware of mycotoxin occurrence, younger traders (age group < 20) and traders with more years in selling (above 5 years) maize are more likely to be aware of mycotoxins occurrences in maize. Fusarium verticillioides were the most predominant species. Most of the isolates were from the Upper East region. Despite the low health risk of the population to ZEA, this research points to the importance of raising traders' awareness to mycotoxins risk and control strategies. (Author)