Latifa A. Al-Husnan1, Muneera D.F. Al-Kahtani1,
Ahmed G. Abdelhamid2 and Randa M.A. Farag1

1Biology Department, Faculty of Science, Princess Nourah bint Abdulrahman
University (PNU). Riyadh, Kingdom of Saudi Arabia (KSA).
2Botany Department, Faculty of Science, Benha University, Benha.


The Current study revealed the natural occurrence of toxigenic fungi and mycotoxins production in grains in Saudi Arabia.Samples of yellow corn, white rice and red corn grains were collected from different local markets. Three fungal isolates were isolated from the examined corn grainsusing PDA media.The toxigenicAlternariaspp.was the most prominent fungi in yellow corn grains, white riceand red corn grains. ThreeAlternariaspp.isolated were identified using molecular characterization of ACTTS gene.DNA genome of the three Alternariasppisolates (namely AWR; AYC and ARC which corresponds to isolates from white rice, yellow corn, red corn)was usedasatemplate for PCR to amplify ACTTS gene. PartiallysequencedACTTSgenewas amplified usinga specificprimer set to confirm its identity, phylogenetic relationships between the three isolates as well as determination of the corresponding antigenic determinants.The epitope prediction analysis demonstrated that there were 5, 6 and 5 epitopes whose score were above 0.90 in AWR, AYC and ARC, respectively.  Interestingly, there were great variations in the epitope sequences among the three isolates except for the epitope, VYGASTATGTLAVQ. This work led to molecular identification of three Alternariaspp. using ACTTS gene and the unique antigenic determinants that could be used for design of a broad spectrum antibody for rapid detection of Alternariaspp. in foods.

Keyword: Mycotoxins, Alternaria,ACTTSgene, PCR, antigenic determinants.