M YCOTOXINS

1. MYCOTOXINS Doç.Dr.Hrisi BAHAR

2. Mycotoxin -1- ►They are secondary metabolites of a fungus that produce toxic results in another organism. ►They are cytotoxic: disrupt cell structures such as membranes, and protein and DNA and RNA synthesis. ►Small molecules – low MW

3. Mycotoxins-2- ►Generally, the highest levels is in substrates with high water activity and warm temperatures. ► Can develop in grains or nuts in the field due to metabolism of pathogenic or saprobic fungi on the living plant ► Can develop in forage grass may contain mycotoxins because of a pathogenic fungus or a fungal endophyte.

4. Mycotoxin-3- ►Lack of visible appearance of fungus does not negate the presence of mycotoxins. ► Toxins can remain in the organism after fungus has been removed. ►Can be heat stable, not destroyed by canning or other processes.

5. Mycotoxin-4- ► More commonly -- mycotoxins develop in storage and remain within the food after processing and cooking ► Many common indoor environmental contaminants are toxigenic - able to produce toxins ► Some studies revealed significant levels of airborne mycotoxins in occupational settings, offices, and even homes ► Mycotoxins are not volatile so exposure must be in airborne spores

6. Information About Fungus ► Range from single cells to fruiting bodies that form molds, mushrooms, smuts, and yeasts. ► Absorb nutrients from living or deceased organisms, contain no chlorophyll. ►Multicellularfungus have tubular filaments called hyphae that branch out. ► Reproduce using spores.

7. Modes of Spore Transmission ► Airborne, wind or indoor ventilation systems. ► Attachment to insects of birds, thus transmitted from plant to plant, or animal to animal.. ► Via transportation mechanisms such as trucks, crop machinery….

8. Fungal Infection ► Can occur at any stage in crop production. ► While in the field. ► During harvesting. ► While in silage and storage. ► Spores can lay dormant for months to years, waiting for positive conditions for germination. www.allaboutfeed.net

9. Conditions to Encourage Fungal Growth ► Relative humidity over 70%. ► Temperatures over 30 degrees Celsius for a period of a few days to a week. ► Stress to the affected plant, such as drought, flood, or insect infestation. ► High moisture content of crop (20% or higher). ► Must occur in conjunction, or fungal growth cycle will cease.

10. Common Toxigenic Fungi Aspergillus Penicillium Stachybotrys Fusarium

11. Mycotoxin Statistics ►300-400 mycotoxins presently identified, with more becoming evident as new isolation techniques are used. ►Most frequent toxins present are aflatoxin, DON, ZEN, fumonisin, and T-2 toxin.

12. Mycotoxins identified in spores

13. Mycotoxin Health Hazards ► Generally lower risk in well developed countries due to improved standards of living. ► High intake of affected product, usually in conjunction with limited amounts of other food sources. ► Greatest threat comes from long term exposure due to eating spoiled food or meat from animals fed contaminated feed.

14. Mycotoxin Effects on Humans ► Economic loss due to impaired health of stock animals. ► Illness: symptoms can include cold/flu-like symptoms, sore throats, headaches, nose bleeds, fatigue, diarrhea, dermatitis, and immune suppression, and vary by species. ► Death.

15. Symptoms of Mycotoxicosis Mycotoxicosisis a systemic poisoning caused by toxins produced by fungal organisms. ►Drugs and antibiotics are not effective in treatment. ►The symptoms can be traced to foodstuffs or feed. ►Testing of said foodstuffs or feed reveals fungal contamination. ►The symptoms are not transmissable person to person. ►The degree of toxicity is subject to persons age (more often in very young and very old), sex ( more often in females than males)and nutritional status. ►Outbreaks of symptoms appear seasonally.

16. Fusarium-1- • Fungal species from the genus Fusarium will attack corn and wheat plants.

17. Fusarium-2- ► Most are plant pathogens and can be found in soil. ► Some examples of affected plants are corn, wheat, barley, beans, with lesser contamination in rye, triticale, millet, and oats. ► Trichothecene toxins target the circulatory, alimentary, skin, and nervous systems.

18. F. graminearum- Wheat ► Causes scab damage to kernels and head blight. ► Produces deoxynivalenol (DON), also called vomitotoxin. DON

19. F. graminearum in Maize (Corn) ►Creates Giberella Ear Rot ►Produces the toxins: DONand zearalenone (ZEN), and T-2 toxins. ►Have damaging effects on plants, humans, and other animals with monogastric digestive processes. Zearalenone T-2 toxin

20. DON and T-2 Toxin ► They cause necrosis and hemorrhagie of the digestive tract, decrease blood production in the bone and spleen. ► Optimal temperature range is between 70 and 85 degrees Farenheit. ► Advisory level of DON is1 ppm. www.zeostore.com

21. Alimentary Toxic Aleukia (ATA) ►During World War II, in Soviet Union, corn grain left to over-winter becomes contaminated with T-2 toxin. ►Severe mycotoxicosis occured. ►Symptoms include burning in the mouth, esophagus, tongue, and stomach. ►Blood marrow formation is halted and anemia develops. ►Hemorrhage of nose, gums,mouth and stomach occurs. http://www.firstchoicemold.com/images/molds/Fusarium-sp..jpg

22. Zearalenone ► A tricothecene. 1. Sources : Fusarium roseum (F.graminearum ):corn, wheat, barley, oats. ► Mimics the body’s production of estrogen. ► Causes feminization of male animals. ► Disrupts conception, ovulation, and fetal development in female animals. ► Pigs are especially sensitive, poultry and cows show little sensitivity.

23. http://www.cropsci.illinois.edu/faculty/pataky/pubs/bytopic/images/seed4.jpghttp://www.cropsci.illinois.edu/faculty/pataky/pubs/bytopic/images/seed4.jpg F. moniliforme ► Plant pathogen most associated with corn. Also found in rice, sorghum, yams, hazelnuts, pecans, and cheeses. ► Diseases associated with this species include “crazy horse disease” in horses, pulmonary edema in pigs, liver cancer in rats, bone malformation in chicks and pigs. ► The fumonisins produced by F. moniliformeare linked with esophageal cancer in humans. ► Other toxins produced include fusaric acid, fusarins, and fusariocins. ► Advisory levels are 5 ppm in animal feed.

24. Claviceps Toxins ► Earliest recognized by mycotoxicosis caused by C. purpurea,an ergot mold. ► Humans who consumed bread baked with grain containing ergot spores, which produced lysergic acid diethylamide (LSD)have symptoms like hallucinations.

25. Ergotism-1- ► Ergot contains a number of toxic alkaloids, if harvested with the grain and milled into the flower - it can cause a disease called ergotism ► During Middle Ages called “Dancing Mania” and “St. Anthony’s Fire” ► Ergotism can also occur in grazing animals that forage on contaminated grain ► Many different alkaloids - -- cause many different effects ► Grains are replaced by ergot sclerotia that contain toxins. ► Main toxin is called ergotamine

26. Ergotism-2- • Gangrenous ergotism - Some of the alkaloids constrict blood vessels and impair circulation • Feelings of burning in calves or intense cold • In extreme conditions can result in gangrene • Limbs may drop off or require amputation • Convulsive ergotism-Other toxins affect the CNS • Hallucinations and convulsions - loss of mental function • Feelings of burning in calves or intense cold

27. Aspergillus Toxins ►Large genus with more than 100 species, 50 of which are known to produce mycotoxins. ► Some of which are aflatoxin, ochratoxin A, sterignmatocystin, cycolopiazonic acid, citrinin, patulin, and tremorgenic toxin. ►Aspergillusniger is used to make artificial citric acid; one use is in soft drinks. ► Miso, soy sauce, and sake use strains of A.oryzae.

28. Aspergillus toxin ► Produced by 3 species of Aspergillus: A. flavus, A. parasiticus, A. nomius ► Aspergillus flavus a common saprobe that occurs on grains and legumes in storage ► A. parasiticus most toxigenic species ►Aflatoxins isnot only toxic but also can be carcinogenic

29. Aflatoxin B-1 ► Aflatoxicosis: is the poisoning that results from ingesting aflatoxins ►Even when levels not toxic, prolonged exposure caused liver cancer in every species of lab animal tested ► Believed responsible for high rates of liver cancer in population groups in Asia and Africa where contaminated food is often consumed ► Toxic effects shown in India in 1974 when hundreds were poisoned by eating corn containing aflatoxins - 106 people died ► Most important crops - peanuts and corn

30. Aflatoxin B-1 ►Risk factor for neonatal jaundice, in areas of maternal consumption. Hepatocellularcarcinoma (HCC) due to aflatoxins is a major cause ofmortality in certain areas of the world ► Does not stay in the body for long periods of time, usually excreted within 96 hours, in animals. ►In milk, for human consumption, advisory level is .5 ppb. ►About 50% of the HCC cases in parts of the world where food is contaminated withAFB1show a mutation in codon 249 of p53 tumor suppressor gene ►Mutation consists of transversion of G->T in the third position of codonresulting inserine instead of arginine - lab studies confirm

31. Penicillium Toxins-1- • Large genus with over 150 species. • Discovered antibacterial properties within genus, causing production of penicillin. • 100 species have mycotoxins. • Nine specific toxins affecting human health are citreoviridin, citrinin, cyclopiazonic acid, ochratoxin A, patulin, penitrem A, PR toxin, Roquefortine C, and, Secalonic acid D.

32. Penicillium Toxins -2- ► Separated into two groups: 1-Those that affect liver and kidneys 2-Those that are neurotoxic. ► Liver and kidney toxins are asymptomatic and cause overall animal debility. ► Neurotoxins cause visible trembling.

33. Ochratoxin ► Produced by species of Aspergillus such as A. ochraceus ► Most important is Penicillium verrucosum which occurs on grains ► Ochratoxin A a nephrotoxin responsible for nephropathy in pigs and probably humans ► It is immunosuppressive and also assumed to be carcinogenic.

34. Ochratoxin A and Citrinin ► Affects kidney function. ► Causes Balkan nephropathy and Yellow Rice Fever in humans. ►Ochratoxin sources are peanuts, pecans, beans, dried fruit and dried fish. ►Citrinin sources are in wheat, rice, corn, and flour. Mostly associated with horses, pigs, dogs, and poultry. Ocratxin A Citrinin

35. Future Fight Against Mycotoxins ► Scientists hope to genetically engineer plants resistant to fungal infection. ► Use feed additives that sequester the toxins and prevent absorption from the gastrointestinal tract. http://mycoglobe.ispa.cnr.it/images/foto_main.jpg

36. Quick Toxin Review

37. ► Mycotoxicoses:Literally, fungus poisonings; current usage limited to poisoning of people and animals by various food and feed products contaminated (and sometimes rendered carcinogenic) by toxin-producing fungi. ► Mycetismus: Mushroom poisoning, formed in the fleshy fruiting bodies of higher fungi. Poisoning resulting from ingestion of mushrooms; ► Potentially deadly mushrooms include Amanita phalloides, A. verna, A. virosa, and certain other species that contain neurotoxins.

38. Amanita phalloides Amanita phalloides Amanita verna Amanita virosa

39. Mushroom poisoning • Rapid identification of mushroom poisoning and treatment is critical. According to the Center for Food Safety and Applied Nutrition of the FDA, persons who have ingested poisonous mushrooms and are treated immediately have a mortality rate of 10 per cent, whereas those who are treated 60 or more hours later have a 60 to 90 per cent mortality rate.

40. Mushroom poisoning • Toxin: A poisonous substance, having a protein structure, that is secreted by certain organisms and is capable of causing toxicosis when introduced into the body tissue. Toxins are also capable of inducing an antitoxin. • Trichothecene: A group of chemically related compounds produced by fungi such as Fusarium

41. Summary of health effects of mycotoxins ► Acute and chronic effects on both humans andlivestock ► Many are potent carcinogens ► Majority of research focused on health effects following consumption of contaminated food ► Effects range from immediate toxic responses and immunosupression to potential long-term carcinogenic effects ► Possible health effects due to airborne exposure (exposure to airborne spores with mycotoxins

42. Detection and Screening of Mycotoxins-1- ► Because of the diverse chemical structures of mycotoxins, the presence of trace amounts of toxins in very complicated matrices that interfere with analysis, and the uneven distribution of the toxins in the sample, analysis of mycotoxins is a difficult task. ► Because many steps are involved in the analysis, it is not uncommon that theanalytical error can amount to 20–30% ►To obtain reliable analytical data, an adequate sampling program and an accurate analytical method are both important.

43. Detection and Screening of Mycotoxins-2- ► To minimize the errors, studies have led to many improved and innovative analytical methods for mycotoxin analysis over the years. ►New, more sensitive TLC, HPLC, and GC techniques are now available. ►The MS methods have also been incorporated into HPLC systems. ►New chemical methods, including capillary electrophoresis and biosensors are emerging and have gained application for mycotoxin analysis.

44. Treatment & Prevention a.For most mycotoxins, there is no specific treatment or antidote b.Detoxification : Hydrated sodium calcium aluminosilicate (HSCAS) can absorb aflatoxins c.Supportive : Vitamin .E & selenium d.Prevention - Mold inhibitor - Treatment of grain with anhydrous ammonia for 10-14 days.