Development of a qPCR assay for the detection of heat-resistant Talaromyces flavus

Int J Food Microbiol. 2018 Apr 2:270:44-51. doi: 10.1016/j.ijfoodmicro.2018.02.010. Epub 2018 Feb 13.

Abstract

Heat-resistant fungi of the species Talaromyces flavus, which inhabits soil and can contaminate fruits, constitutes significant impact on spoilage of heat-processed food. T. flavus possess the ability to produce numerous mycotoxins and is able to survive the process of pasteurization what makes it a treat to food industry. Up to date there is no rapid and reliable method to detect and identify T. flavus. Therefore in this study, a sensitive method for detecting T. flavus was developed. The primers (Tf1_F/R) specific to detection of DNA replication licensing factor gene of T. flavus were designed. With this set of primers, a qPCR reaction with SybrGreen detection was developed. The specificity of assay with use of 5 T. flavus strains and 35 other fungal isolates was tested. The detection threshold was 200 fg of T. flavus genomic DNA. The developed method was able to detect 640 ascospores in 1 g of strawberry fruits and soil samples.

Keywords: Heat-resistant fungi; Soil; Strawberry; Talaromyces flavus; qPCR.

MeSH terms

  • DNA Primers / genetics
  • DNA, Fungal / analysis*
  • DNA, Fungal / genetics
  • Food Microbiology
  • Food-Processing Industry
  • Fragaria / microbiology
  • Hot Temperature
  • Limit of Detection
  • Minichromosome Maintenance Proteins / genetics*
  • Mycotoxins / metabolism
  • Pasteurization
  • Polymerase Chain Reaction / methods*
  • Soil Microbiology
  • Spores, Fungal / genetics
  • Spores, Fungal / isolation & purification*
  • Talaromyces / genetics*
  • Talaromyces / isolation & purification

Substances

  • DNA Primers
  • DNA, Fungal
  • Mycotoxins
  • Minichromosome Maintenance Proteins