Ochratoxin A in human blood in Abidjan, Côte d'Ivoire.

Ochratoxin A (OTA) produced by Aspergillus and Penicillium genera contaminates a diversity of foods including cereals; cereals-derived foods; dry fruits; beans; cocoa; coffee; beer; wine; and foodstuffs of animal origin mainly poultry, eggs, pork and milk, including human breast milk. OTA is nephrotoxic to all animal species studied so far and most likely to humans, who show the longest half-life for elimination of this toxin among all species examined. Among other toxic effects, OTA is teratogenic, immunotoxic, genotoxic, mutagenic and carcinogenic, all of which lead to life-threatening pathologies through several molecular pathways. In Côte d'Ivoire, preliminary surveys conducted by us have proven from 1998 to 2004 the reality of ochratoxin A-contamination of foodstuffs. To assess OTA in human blood, the immunoaffinity columns were used along with HPLC for separation and fluorimetric quantification of blood samples collected in Abidjan from two categories of people: apparently healthy donors (n=63) and nephropathy patients undergoing dialysis (n=39). Among healthy donors, 34.9% show OTA concentrations ranging from 0.01 - 5.81 microg/l with a mean value of 0.83 microg/l, whereas, among nephropathy patients undergoing dialysis 20.5% are OTA positive in a range of 0.167-2.42 microg/l and a mean value of 1.05. Although the sex ratio is 0.82 (46 females for 56 males) ochratoxin A contamination is equally distributed in both sexes. Nephropathy patients undergoing dialysis appear, however, less frequently contaminated than healthy donors (20.5 versus 34.9%) and show higher OTA concentrations (higher mean value, p=0.01). Ochratoxin A concentrations found in human blood reflect concentrations previously detected in cereals and peanuts according to the eating habits and diets of people in Côte d'Ivoire. But, the prevalence of ochratoxin A in blood of nephropathy people undergoing dialysis appears lower than expected from the frequency of OTA contamination in cereals and peanuts. Pearson chi(2)-test indicates that among OTA-positive individuals renal dialysis and age are important modalities for consideration.

Ochratoxin A levels in human plasma and foods in Lebanon.

Ochratoxin A (OTA) is a widespread mycotoxin which contaminates food such as cereals, beer, coffee, wine and products of animal origin. OTA is known for its nephrotoxic, immunotoxic and carcinogenic properties. The prevalence of OTA in human blood and foodstuffs has been investigated in many countries. In this study, exposure of the Lebanese population to OTA was evaluated and the contamination of the most commonly consumed foods in Lebanon by OTA was assessed. Plasma samples from healthy individuals and also cereals and beer samples obtained from markets were collected from the different regions of Lebanon. OTA was detectable in 33% of tested plasma samples (n =250) with a concentration ranging from 0.1 to 0.87 ng/mL and a mean of 0.17+/-0.01ng/mL. No sex and age differences were found. The frequency of OTA-positive plasma samples obtained in the South of Lebanon and in the Bekaa valley (50 and 47%, respectively) was significantly higher compared to plasma samples obtained in the Beirut/Mount Lebanon region (19%). Food analyses showed that wheat, burghul and beer were contaminated with a mean value of 0.15+/-0.03 microg/kg, 0.21+/-0.04 microg/kg and 0.19+/-0.12 ng/mL, respectively. These data suggest that the Lebanese population is exposed to OTA through food ingestion at concentrations lower than the tolerable daily intake.

Co-occurrence of aflatoxin B1, fumonisin B1, ochratoxin A and zearalenone in cereals and peanuts from Côte d'Ivoire.

This survey examined 30 samples of rice (n = 10), maize (n = 10) and peanuts (n = 10) from Côte d'Ivoire for aflatoxin B1, fumonisin B1 and zearalenone using immunoassays, and ochratoxin A using a validated HPLC method with fluorescence detection. In Côte d'Ivoire, as in other countries, several mycotoxins are present in the same commodities. These mycotoxins are from different structural families: aflatoxin B1, fumonisin B1, zearalenone and ochratoxin A, normally produced by fungal species from Aspergillus, Penicillium and Fusarium genera. Some samples contained four mycotoxins (86%). Four peanuts samples did not show ochratoxin A (14%), whereas they contained aflatoxin B1 concentrations above the EU regulatory limits. Concentrations of ochratoxin A, zearalenone and fumonisin B1 were low and may not cause problems per se; however, fears remain that the tolerable daily intake may be exceeded due to eating habits and synergistic effects could be important with the combination of several mycotoxins. Investigations in this direction are underway, together with isolation and characterization of the fungal species involved.