Molecular Analysis of Aspergillus Species which Contaminate Grapes Sold in Maringá PR Brazil

Abstract

Food contamination by fungi may cause health risks, especially when mycotoxins are produced. Ochratoxin A (OTA) has been focused due to the production of several toxic carcinogenic, teratogenic, immunosuppressor and nephrotoxic effects. OTA is mainly produced by Aspergillus fungi which may contaminate grapes during the various production stages. Traditional techniques for the identification of mycotoxin-producing fungus species are slow and normally the morphological characteristics are insufficient to distinguish close species. The use of molecular techniques for detection is thus required. Current analysis aims at the molecular identification of Aspergillus niger and Aspergillus carbonarius in grape samples collected in Maringá PR Brazil. Analyses were undertaken from a collection of 30 grape samples in markets and fairs, with culture in sabouraud medium and chloramphenicol to obtain the mycelium. When positive, the sample was submitted to DNA extraction and quantification process, followed by the amplification of genetic material with specific primers. Further, 26.67% of the 30 samples had characteristic fungus growth and underwent molecular analysis, of which 25% were identified as A. niger and 12.5% as A. carbonarius. Molecular tests were efficient to detect toxin-producing fungus species in grapes sold in Maringá PR Brazil. Microbiological analysis evidenced other fungus species in the samples although distinction at species level was not possible. Additional molecular tests were required.