Research Article

Use of molecular markers to compare Fusarium verticillioides pathogenic strains isolated from plants and humans

Published: August 12, 2013
Genet. Mol. Res. 12 (3) : 2863-2875 DOI: 10.4238/2013.August.12.2

Abstract

Fusarium verticillioides is a pathogen of agriculturally im­portant crops, especially maize. It is considered one of the most impor­tant pathogens responsible for fumonisin contamination of food products, which causes severe, chronic, and acute intoxication in humans and ani­mals. Moreover, it is recognized as a cause of localized infections in im­munocompetent patients and disseminated infections among severely im­munosuppressed patients. Several molecular tools have been used to ana­lyze the intraspecific variability of fungi. The objective of this study was to use molecular markers to compare pathogenic isolates of F. verticillioides and isolates of the same species obtained from clinical samples of patients with Fusarium mycoses. The molecular markers that we used were inter-simple sequence repeat markers (primers GTG5 and GACA4), intron splice site primer (primer EI1), random amplified polymorphic DNA marker (primer OPW-6), and restriction fragment length polymorphism-internal transcribed spacer (ITS) from rDNA. From the data obtained, clusters were generated based on the UPGMA clustering method. The amplification products obtained using primers ITS4 and ITS5 and loci ITS1-5.8-ITS2 of the rDNA yielded fragments of approximately 600 bp for all the isolates. Digestion of the ITS region fragment using restriction enzymes such as EcoRI, DraI, BshI, AluI, HaeIII, HinfI, MspI, and PstI did not permit dif­ferentiation among pathogenic and clinical isolates. The inter-simple se­quence repeat, intron splice site primer, and random amplified polymorphic DNA markers presented high genetic homogeneity among clinical isolates in contrast to the high variability found among the phytopathogenic isolates of F. verticillioides.

Fusarium verticillioides is a pathogen of agriculturally im­portant crops, especially maize. It is considered one of the most impor­tant pathogens responsible for fumonisin contamination of food products, which causes severe, chronic, and acute intoxication in humans and ani­mals. Moreover, it is recognized as a cause of localized infections in im­munocompetent patients and disseminated infections among severely im­munosuppressed patients. Several molecular tools have been used to ana­lyze the intraspecific variability of fungi. The objective of this study was to use molecular markers to compare pathogenic isolates of F. verticillioides and isolates of the same species obtained from clinical samples of patients with Fusarium mycoses. The molecular markers that we used were inter-simple sequence repeat markers (primers GTG5 and GACA4), intron splice site primer (primer EI1), random amplified polymorphic DNA marker (primer OPW-6), and restriction fragment length polymorphism-internal transcribed spacer (ITS) from rDNA. From the data obtained, clusters were generated based on the UPGMA clustering method. The amplification products obtained using primers ITS4 and ITS5 and loci ITS1-5.8-ITS2 of the rDNA yielded fragments of approximately 600 bp for all the isolates. Digestion of the ITS region fragment using restriction enzymes such as EcoRI, DraI, BshI, AluI, HaeIII, HinfI, MspI, and PstI did not permit dif­ferentiation among pathogenic and clinical isolates. The inter-simple se­quence repeat, intron splice site primer, and random amplified polymorphic DNA markers presented high genetic homogeneity among clinical isolates in contrast to the high variability found among the phytopathogenic isolates of F. verticillioides.