PCR Detection ofAlternariaspp. in Processed Foods, Based on the Internal Transcribed Spacer Genetic Marker

The genusAlternariais considered one of the most important fungal contaminants of vegetables, fruits, and cereals, producing several mycotoxins that can withstand food processing methods. Conventional methods for Alternariaidentification and enumeration are laborious and time-consuming, and they might not detect toxigenic molds inactivated by food processing. In this study, a PCR method has been developed for the rapid identification of Alternariaspp. DNA in foodstuffs, based on oligonucleotide primers targeting the internal transcribed spacer (ITS)1 and ITS2 regions of the rRNA gene. The specificity of the Alternaria-specific primer pair designed (Dir1ITSAlt-Inv1ITSAlt)was verified by PCR analysis of DNA from various Alternariaspp., and also from several fungal, bacterial, yeast, animal, and plant species. The detection limit of the method was 10 2 CFU/ml in viable culture, heated culture, or experimentally inoculated tomato pulp. The applicability of the method for detection ofAlternariaspp. DNA in foodstuffs was assessed by testing several commercial samples. AlternariaDNA was detected in 100 (percent)of spoiled tomato samples, 8(percent)of tomato products, and 36.4(percent)of cereal-based infant food samples analyzed.