Molecular Diagnosis of Ochratoxigenic Fungi

Abstract

Ochratoxin A (OTA) is one of the most abundant food-contaminating mycotoxins. Its presence in several agricultural commodities has been considered a problem worldwide. This toxin is mainly produced by two genera of fungi: Aspergillus and Penicillium. Ochratoxin A has nephrotoxic, immunosuppressive, and carcinogenic effects; consequently, contamination with OTA presents a major risk for human and animal health. Over the last 5 years, several studies have developed PCR-based assays for identifying and quantifying OTA-producing fungi in food samples. The main objective of these assays is to allow the detection of microorganisms capable of producing OTA, prior to ochratoxin production and accumulation. Several of these attempts will be reviewed and discussed in this chapter.

Molecular Characterization of Ochratoxigenic Fungi Associated with Raisins

“…Hence, it is imperative to develop methodologies that are relatively rapid, highly specific and as an alternative to the existing methods. The application of molecular biology techniques can help to overcome these problems because it can reduce the time for identification from days to hours and also allow precise species identification (Sartori et al 2010). PCR-based methods that target DNA are considered a good alternative for rapid diagnosis because of their high specificity and sensitivity (Accensi et al 1999, Perrone et al 2004, especially when multi-copy sequences are used to develop species specific primers (Bluhm et al 2002).…”

Evaluation of the Antifungal Activity of Cinnamon, Clove, Thymes, Zataria Multiflora, Cumin and Caraway Essential Oils against Ochratoxigenic Aspergillus ochraceus

“…Loss of nutritional value and quality loss such as loss of sensory characteristicappearance, loss of color and taste, and Food Rotting are considered as consequences of fungal damage [2]. Some Aspergillus species are also able to produce mycotoxins in addition to undesirable appearance of the food [3]. Some of these toxins include ochratoxin, aflatoxin, patulin, strigmatoxin, penicillic acid and cyclopiazonic acid [4].…”

“…Ochratoxin (OTA) is known as a nephrotoxin for mammals, and OTA was also categorized in Group 2B of the International Agency for Cancer Research (IARC) in 2004 [5]. This mycotoxin has carcinogenic, teratogenic and immunotoxic effects for rats and probably human [3]. Regarding to the adverse effects of fungicides on health and the environment, and on the resistance of strains to drugs and synthetic chemical compounds, researchers have focused on more natural and safe chemical compounds [6][7][8].…”

Identification of Genes Differentially Expressed Between Ochratoxin-Producing and Non-Producing Strains of Aspergillus westerdijkiae

“…Aspergillus westerdijkiae is a filamentous fungus that was dismembered from the A. ochraceus taxa [1]. Several strains of A. westerdijkiae, about 70 %, are able to produce ochratoxin A (OTA), a nephrotoxic and carcinogenic mycotoxin that have been found in cereal and food commodities.…”