Oligonucleotide microarray for the identification of potential mycotoxigenic fungi

Abstract

BackgroundMycotoxins are secondary metabolites which are produced by numerous fungi and pose a continuous challenge to the safety and quality of food commodities in South Africa. These toxins have toxicologically relevant effects on humans and animals that eat contaminated foods. In this study, a diagnostic DNA microarray was developed for the identification of the most common food-borne fungi, as well as the genes leading to toxin production.ResultsA total of 40 potentially mycotoxigenic fungi isolated from different food commodities, as well as the genes that are involved in the mycotoxin synthetic pathways, were analyzed. For fungal identification, oligonucleotide probes were designed by exploiting the sequence variations of the elongation factor 1-alpha (EF-1 α) coding regions and the internal transcribed spacer (ITS) regions of the rRNA gene cassette. For the detection of fungi able to produce mycotoxins, oligonucleotide probes directed towards genes leading to toxin production from different fungal strains were identified in data available in the public domain. The probes selected for fungal identification and the probes specific for toxin producing genes were spotted onto microarray slides.ConclusionsThe diagnostic microarray developed can be used to identify single pure strains or cultures of potentially mycotoxigenic fungi as well as genes leading to toxin production in both laboratory samples and maize-derived foods offering an interesting potential for microbiological laboratories.

DNA Microarrays for Pathogen Detection

“…Further improvements in microarray technology allowed the development of an identification method for oligonucleotide microarray for the identification of potential mycotoxigenic fungi without amplification of target DNA [170]. It was fluorescently labeled using a random approach.…”

Molecular strategies for detection and quantification of mycotoxin‐producing Fusarium species: a review

“…Furthermore, Lezar and Barros reported an oligonucleotide microarray to identify potential mycotoxigenic fungi, in which the oligonucleotide probes were designed by EF‐1a or genes involved in the mycotoxin synthetic pathways. The method identified a total of 32 fungi with their potential to produce mycotoxins, such as trichothecenes and fumonisin …”

Food, Nutrition and Agrobiodiversity Under Global Climate Change

“…The initial application of this microarray demonstrates that it is specific in detecting the signals of gene expression under conditions conducive for mycotoxin biosynthesis, with insignificant cross-hybridizations. Recently, Lezar and Barros (2010) reported a diagnostic oligonucleotide microarray to identify the most common food-borne fungi, as well as the genes, leading to toxin production. By using this array, they could identify 32 fungi, and determined their potential to produce mycotoxins.…”