Detection of Aflatoxigenic and Non-Aflatoxigenic Isolates of Aspergillus flavus Isolated From Some Clinical and Environmental Sources by HPLC and PCR Techniques

Abstract

This study aimed to determine the role of polymerase chain reaction (PCR) and High-performance liquid chromatography (HPLC) technique in the discrimination between aflatoxigenic and non-aflatoxigenic isolates of Aspergillus flavus. The isolates were identified based on macroscopical and microscopical characteristics, and extracted aflatoxin was detected by HPLC technique. Furthermore, DNA was extracted from the all isolates and carried out by PCR to amplify target genes encoding for toxin production (nor-1, ver-1 and aflR). The results showed that the genes (aflR, nor-1) were found in 11 (73%) of isolates, while the (ver-1) gene appeared in 10 (67%) of isolates. Both aflatoxigenic and non-aflatoxigenic isolates were also determined depending on the amplification of gene sites in the targeted DNA. HPLC technique has also used with high efficiency to ensure the aflatoxin-producing isolates and to evaluate the level of aflatoxin B1 production for 15 isolates of A. flavus. Ten isolates were able to produce aflatoxin with rates ranged from 0.78 to 45.03 ppm. PCR technique has proved high efficiency in the differentiation between aflatoxigenic and non-aflatoxigenic isolates of A. flavus. Moreover, aflatoxin production was directly associated with gene appearance and gene detection. Also, HPLC technique is a standard and superb technique in identifying and analyzing aflatoxin with high sensitivity and accuracy.