Thirty Years (1978 - 2008) of Mycotoxins Research at Faculty of Agriculture, Almansoura University, Egypt

This review article illustrates the efforts which were done throughout thirty years in the field of mycotoxins; whether for developing the detection methods of some mycotoxins, natural occurrence of these mycotoxins, preserving methods against fungal invasion and mycotoxins production, describing the toxic symptoms of some mycotoxicoses by different animal species, or treating attepts of some mycotoxicoses often found under Egyptian conditions.


Introduction

The actual beginning of the mycotoxins' story was in the early 1960s in the United Kingdom by discovering the aflatoxins. Thereafter, many other mycotoxins were discovered through improving the detection methods^{(1, 2, 41)}. So, intensive researches all over the world were carried out to detect these mycotoxins in various commodities^{(3, 4, 5, 6, 7, 8, 9, 12, 14,15,17,19,20, 21, 30, 44, 53, 54 66, 68, 72, 73)}. Survey of toxigenic fungi in the environment was done too, besides studying the environmental conditions, which are required for these fungi to produce their toxins^{(59, 62, 63, 64)}. This step was followed by studying the harm effects of mycotoxicoses in different animal species and human being, whether those caused by the individual or combined mycotoxins^{(1,10, 11, 13, 22, 23, 24, 25, 26, 27, 28, 31, 42, 43, 46, 47, 48, 51, 55, 65, 67)}. Recently, attempts were investigated to eliminate, detoxify or alleviate the toxic effects of mycotoxins^{(16, 29, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 45, 49, 50, 52, 56, 57, 58, 60, 61, 69, 70, 71)}


Detection methods

Chromatographic methods of detection are the main means of mycotoxins estimation; so, two different methods were developed for quantitative determination of ochratoxin-A⁽⁷⁵⁾ and fusariotoxins (zearalenone and vomitoxin)⁽⁷⁴⁾, respectively using high performance liquid chromatography. These methods are rapid and specific for various food and feed stuffs. The first one has an average recovery of about 50% in a range of 50 - 500 ppb and detection limit of 5 ppb ochratoxin-A⁽⁷⁵⁾. The second method has detection limit of 2 ppb zearalenone and 70 - 80% recovery, whereas the detection limit in mixed feed with interfering substances was 25 ppb with 25 - 35% recovery⁽⁷⁴⁾. However, thin layer as well as high performance liquid (or gas) chromatographic methods⁽²⁾ were developed for simple, rapid and accurate quantitative determinations of aflatoxins, ochratoxin, citrinin, zearalenone, vomitoxin, T2 - toxin and diacetoxyscirpenol (Table 1). The optimum conditions for mycotoxins separation by thin layer chromatography were rationalized too⁽¹⁸⁾.


Table(1): Accuracy of mycotoxins analysis means thin layer chromatography.

Occurrence

Peanuts have the highest level of aflatoxins, the contamination rate between their pods' shells/beans was 7/1. Aflatoxin B1 may often occur alone (in 76% of the contaminated samples); so, the contamination rate by aflatoxins B1; G1 : B2 was 22.4 : 2.3 : 1^{(5, 14)}. About ninety percent of the aflatoxin, ochratoxin or zearalenone contaminated samples have a level lower than 100 ppb, whereas the majority (90%) of samples contaminated with vomitoxin have a level higher than 100 ppb⁽¹⁴⁾.

Zearalenone detection was an indicator for other fusariotoxins contamination⁽⁷³⁾. Also, vomitoxin presence was a good indicator for existence of other fusariotoxins such as T-2 toxin, T-2 tetraol, diacetoxyscirpenol and fusarenon-X as a case of multi-contamination. Moreover, there were positive correlations between grains humidity on one side and zearalenone as well as citrinin contamination levels(18) on the other side. However, substrate moisture content is the main environmental factor responsible for mycotoxin production^{(14, 59)}, besides the substrate it self^{(14, 53, 73)}, mechanical damage⁽⁵⁹⁾ and the incubation period⁽⁶⁴⁾, e.g. aflatoxin concentration in feedstuffs had started to fall after 3 weeks storage and by 6 weeks had began to disappear⁽⁶⁴⁾. In the following, Table (2) illustrates the natural occurrence of some mycotoxins under Egyptian conditions.


Table (2): Natural occurrence of mycotoxins in animal feeds and human foods.

* Liver and kidneys from beef and buffalo calves as well as from sheep, but not camels.
** Blood, urine and vomitus of foodborne mycotoxic (poisoning) patients.

Preserving

Raising moisture content of maize up to 16 - 20% led to reduction of dry matter, nitrogen free extract and the bulk density of the moisten samples and elevation of ash and total count of fungi, even with the presence of different preserving agents; except when chamomile, cinnamon, pepper, maleic acid, potassium benzoate, sodium carbonate and multifungin were added at 1.5%. These additives prevent fungi to produce aflatoxins as well as ochratoxin-A, while some samples were positive for citrimin and/or zearalenone. Since the addition of chamomile, cinnamon, potassium benzoate and multifungin individually to corn samples prevented the formation and accumulation of citrinin and zearalenone as well as reduced the fungal population of Fusarium, Penicillium, Aspergillus and Rhizopus⁽⁵⁹⁾.

Autoclaving, drying, sun light, room temperature, cooling and freezing, respectively could decompose aflatoxins, in a descending order according to the destruction rate. Decontamination tended to decrease by increasing the initial level of the aflatoxins before the treatment. Yet, the destruction increased in the time course of the treatment or its temperature. Loss of aflatoxins G was higher than that of aflatoxins B. But, autoclaving affects the appearance (led to hard-sticky food with dark coloration) and digestibility of the treated food⁽¹⁶⁾. Moreover, autoclaving has restricted apparent destruction rate (41.8 - 42.2%) for aflatoxin B1 (and lower rate for ochratoxin A, being 11.3 - 27.7%), since the biological test by fish revealed its toxic effects after autoclaving the aflatoxic aqua feed⁽⁵⁴⁾.

Adsorbents reduced aflatoxin level by about 16 - 44%, but autoclaving and using microwave reduced its concentration by 33 and 53%, respectively. High temperature negatively affected appearance, consistency and composition of a treated food. Hydrogen peroxide and ammonization led to reduction of aflatoxin concentration by 38 and 88%, respectively, whereas methanol extraction reduced it by 54% and led to reduction of crude protein⁽³⁵⁾.


Toxic symptoms

Moldy diet decreased the feed intake and digestibility and increased the water consumption, particularly water/feed ratio. It led to atrophy of liver and spleen and heaviness of the empty stomach and female genital tract. It also was responsible for decreased cholesterol / phospholipids ratio and increased calcium/phosphorus ratio in rabbit's serum⁽¹³⁾.

Moldy diet was rich in ash and silica contents, so reduced feed intake and nitrogen and calcium retention by sheep. It led also to decline blood total nitrogen, calcium, calcium/phosphorus ratio and cholesterol/calcium ratio. Urine analysis revealed increases in calcium, magnesium and vitamin C, whereas pH values, total nitrogen and phosphorus were declined. So, moldy feeds seemed to have toxic, nephritic and hepatic effects⁽⁴⁸⁾.
Sterigmatocystin led to decrease growth of fish and their muscle protein but increase their mortality, serum aminotransferases activity and muscle fat content. There were pathological changes and sterigmatocystin residues in fish muscles⁽¹¹⁾.

Dietary aflatoxin negatively affected rats body gain, feed intake and efficiency, survival rate, blood picture, and relative weights of the internal organs^{(45, 61)}. It increased the blood albumin/globulin ratio, hepatic nucleic acids and blood urea concentrations, white blood cells count, and activity of blood alkaline phosphatase and aspartate amino transferase but reduced blood acid-phosphatase activity, iron concentration, and hemoglobin level⁽⁶¹⁾.

Aflatoxins were causative of decreased feed intake, body weight and survival rate of rabbits. Relative weights of liver, kidneys, heart and adrenal glands were increased but hemoglobin content, packed cell volume percentage and sedimentation rate were decreased. Aflatoxin led also to increase blood lipids and water content of rabbits' muscles and liver but reduced bone ash and volume. There were aflatoxin residues in muscles, serum, liver, heart and kidneys with concentration relationships of 51 : 24 : 3 : 2 : 1, respectively. Aflatoxin caused paralysis, disorder of fat deposition, hemorrhages, and pathological changes⁽⁴⁷⁾.

Aflatoxicosis by rabbits characterized by felt fur, high body temperature, loss of appetite, weakness, bloody diarrhea, nervous movements, paralysis and death. The post-mortem examination revealed presence of internal hemorrhages and congested-enlarged organs. It lowered the body weight, feed utilization and blood values of hemoglobin, packed cell volume, red blood cells count, glucose and cholesterol. It increased the relative weight of liver and kidneys, the activity of blood transaminases and concentrations of blood urea, uric acid and creatinine. Its residues accumulated in liver > muscles > heart > kidneys at levels proportional to those consumed in the diet⁽⁵⁸⁾.

Low level of dietary aflatoxin negatively affected chicks' body weight, feed conversion, digestibility of nutrients, dressing percentage, relative weights of liver and kidneys, mortality rate, internal gross pathology^{(40, 54)} and biochemical characteristics of muscles, liver, bone and blood as well as semen quality^{(37, 41)}, besides symptoms of low viability, anorexia, peruses, ataxia, scattered feathering, hemorrhage, cramps, stinked excrements, edema, pale-yellowish liver, friable kidneys, dark colored gall bladder and congestion of glands, lungs and gonads⁽³⁹⁾. Aflatoxic patients suffered from food poisoning(20) with abdominal colic, vomiting, diarrhea and pallor; particularly with groups of younger age, female, students, and from rural areas of low economic status(44), and nephropathy⁽³⁰⁾.

Dietary aflatoxin decreased body gain, growth rate, survival rate, feed conversion, nutrients utilization, and muscular protein, but increased carcass fat of intoxicated fish^{(32, 52, 57, 60)}. It increased the internal organs' indices and white blood cells count besides activity of alkaline phosphatase and transaminases and the aflatoxin residues, but decreased hemoglobin concentration, packed cell volume, total protein and red blood cells' count. Its residues were found in the whole body and tended to decrease after freezing period^{(33, 52, 57, 60)}.

Aflatoxin reduced the area of fish muscles, caused chromosomal aberrations and lower mitotic index. Severity of its harmful effects correlated positively with its dietary levels. Its effects varied between fish sizes⁽⁵⁵⁾.

Ochratoxicosis-A by rabbits reflected clinical symptoms including feed refusal, increased pulse rate, hard breathing, land lay, and slack. The post-mortem examination revealed presence of blue spots on the lungs; hemorrhagic patches on the esophagus, stomach, intestine, heart, liver, and kidneys; and dilated kidneys. The blood analysis indicated increases in concentrations of creatinine, urea, uric acid, cholesterol and transaminases activity; whereas decrease of blood total proteins concentration was recorded. Residues of ochbratoxin-A were found at highest level in the kidneys followed by liver, blood, muscles, spleen, heart and feces, respectively with higher concentrations in females than in males' tissue. Yet, lungs, bran, and gonads were ochratoxin-A free. The histological test cleared that the liver suffered from congestion of the central vein, cellular infiltration, and nodular hyperplasia and vacuolization of the hepatocytes. The kidney showed also hyalinization and degeneration of the glomeruli with tubular cell necrosis and degeneration of the proximal and distal tubules⁽⁴⁶⁾.

Oxalic acid mycotoxin decreased the rabbits' body weight gain and feed intake and efficiency but increased its level in animals' blood proportionally to its dietary level. It led to stress symptoms, which tended to be severer by elongation of the feeding period (at the height levels) followed by death. Post-mortem test revealed presence of inflammation and congestion along the digestive system; blue spots on the esophagus, stomach and intestine, hemorrhagic patches on stomach, intestine, liver, lungs and kidneys; pale lungs; enlarged-dark kidneys and liver; and white crystalline precipitations (gout) in the stomach. It increased the weights of kidneys and liver but decreased the carcass weight. It increased also the activity of blood transaminases and the concentrations of blood cholesterol, creatinine and uric acid, but decreased the blood total protein level. Oxalic acid accumulated in muscles, liver, and kidneys, respectively in descending order with higher levels in male than female organs. Histopathologically, it led to mild congestion of the portal vein in the portal tract. Kidneys showed a degeneration of the glomeruli, polymorphonuclear leucocytes infiltration, interstitial nephritis, and oxalate deposition⁽³¹⁾.

Zearalenone elevated body weight gain, feed intake, water consumption, digestibility, hemoglobin level, packed cell volume and concentrations of serum calcium, phosphorus and vitamin C in young rabbits. Yet, the opposite trend was reported in old rabbits fed on diets contaminated with zearalenone. Zearalenone caused noticeable histopathological changes in liver, kidneys, lungs, heart, adrenal glands, spleen and uterus⁽⁵¹⁾. Zearalenone naturally contaminated diet of sheep reduced nitrogen and calcium retention; yet, it increased digestibility of dry matter, crude fiber and energy. It had toxic, nephritic and hepatic effects⁽⁴⁸⁾.

Table (3) illustrates the performance, clinical, pathological, histological, and blood parameters observed or estimated by different animal species under mycotoxicoses.


Table 3 : Negative (-) effects of different mycotoxins

ANB₁: aflatoxin B₁, ANs: aflatoxins B & G, ONA: ochratoxin A, CN: citrinin, ZN: zearalenone, PA: penicilic acid, RNB: rubratoxin B, SN: sterigmatocyctine, MNs: mixture of mycotoxins, OA: oxalic acid, Clin.Symp.: clinical symptoms, FC: feed conversion, ALP: alkaline phosphatase, RBCs: red blood cells, WBCs: white blood cells, Hb: hemoglobin, Ht: hematocrite, S.: serum, vit.: vitamin, M.: muscular, B.: bone, phys. Char.: physical characteristics (lean meat %, texture index, feder value).


Treating

Elevating dietary protein may alleviate sterigmatocystin toxic effects and residues in fish⁽¹¹⁾. Increasing dietary energy was beneficial to overcome the aflatoxic effects on the body weight, feed conversion, dressing percentage, relative weights of liver and kidneys and mortality of the chicks. The withdrawal of aflatoxic diet improved the dressing percentage and, to some extent, the post-mortem examination⁽⁴⁰⁾, as well as the biochemical characteristics of chicks' muscles and blood⁽⁴¹⁾.

Dietary supplementation of selenium and vitamin E alleviated the toxic effects of the aflatoxic diets of mature cocks concerning body weight gain and feed intake due to increased aflatoxin excretion. Also, vitamins-mixture supplementation and the withdrawal of the contaminated diets lowered the severity of aflatoxicosis by chickens^{(37, 39)}. Dialysis of nephropathy patients led to low content of aflatoxin (and ochratoxin) in their urine, even still higher than in the control people⁽³⁰⁾. Dietary inclusion of charcoal in the aflatoxic diet may improve, to some extent, the severity of aflatoxicosis by rabbits⁽⁴⁷⁾.

Aluminosilicate and tafla addition to the aflatoxic diet lowered-to some extent- the severity of the aflatoxicosis by rabbits. So, it become clear to what extent is the seriousness of foodborne aflatoxicosis by animals and consequently by consumers. Adsorbents still neither obstacle nor sufficient mean for removing aflatoxin and its toxic effects⁽⁵⁸⁾.

Dietary inclusion of adsorbent (like egg shells and shrimp shells) was useful in reducing the toxic effects of aflatoxin on fish, where it increased the body gain, growth, survival, feed conversion and nutrients utilization. It improved also carcass composition of the aflatoxicated fish⁽³²⁾. Moreover, it increased hemoglobin concentration and red blood cells count and decreased white blood cells count, activity of alkaline phosphatase and transaminases and most of the internal organs' indices. It alleviated the adverse effects of aflatoxin on the histopathological changes in different organs⁽³³⁾. Dietary inclusion of egg shell and clay proved to overcome some aflatoxic symptoms by fish⁽⁵⁷⁾.

Moreover, dietary addition of tafla, ammonia or hydrogen peroxide decreased the deleterious effects of aflatoxic diets on rats' performance and blood parameters. The effective additive to partially protect against the negative effect of aflatoxin was tafla. Aflatoxin excreted in feces was higher in rats fed the aflatoxic diet with different additives than in those fed the aflatoxic diet alone. Yet, the different dietary additives did not remove the toxic effects of aflatoxin. Therefore, it is to impose upon the concern of prophylaxis against fungal invasion of feed stuffs to prevent mycotoxin production⁽⁴⁵⁾.

Dietary Biogen^® inclusion reduced severity of aflatoxin contaminated diet on fish but did not lead to its detoxification. Thus, it is emphasized to hygienic control of feeds to avoid their fungal invasion by toxigenic fungi, since prophylaxis is more useful than medication⁽⁵²⁾.

Dietary ginger inclusion alleviated aflatoxicosis symptoms by fish, followed by aspirin and chamomile flowers, respectively as partial detoxifying agent of aflatoxin⁽⁶⁰⁾. However, dietary addition of medical herbs, i.e. safflower, black cumin, ginger, thyme or garlic improved the ammunity of aflatoxic rats and prevented the existence of residual aflatoxin; yet, all these additives histologically altered each of liver and kidney of the animals. No one of the tested medicinal herbs completely overcome the effects of foodborne aflatoxicosis⁽⁶¹⁾.


References

1- Abd-Allah, G. A., S. E. Mansy, A. M. Abdelhamid, and T. M. Dorra (1992). Aflatoxicosis induced in rats from the residues of aflatoxin B1 in the flesh of chickens fed on contaminated mash. J. Egypt. Ger. Soc. Zool., 8(A): 37-49.

2- Abdelhamid, A. M. (1981). Mycotoxine in östereicheschen Futtermitteln. Vet. Med. & Bodk. Univ., Wien, Österreich.

3- Abdelhamid, A. M. (1983). Occurrence of vomitoxin in some Egyptian foods and feeds. In: Abstracts book of the International Mycotoxin Conference, Cairo, No. 59.

4- Abdelhamid, A. M. (1983). Detection of citrinin in some Egyptian food and feed stuffs. In: Abstracts book of the International Mycotoxin Conference, Cairo, No. 60.

5- Abdelhamid, A. M. (1983). Mykotoxin-Nachweis in Lebens-und Futtermitteln des subtropischen Klimas. In: Kurzfassungen der Vorträge zur 37. Tag. Ges. Ernährungsphysiol. Haustiere, Göttingen, 5. Z. Tierphysiol., Tierernährug u Futtermittelkde., 50: 4-5 (Egyptian Agricultural Bibliography, IX, 1986, 85-100438).

6- Abdelhamid, A. M. (1983). Existence of zearalenone (F2) in the Egyptian foods and feeds. In: Proceedings of the 1st African Conference of Food and Technology, Cairo, pp: 592-603.

7- Abdelhamid, A. M. (1983). Detection of ochratoxin-A in the Egyptian food and feed stuffs. In: Proceedings of the 1st African Conference of Food and Technology, Cairo, pp: 604-613.

8- Abdelhamid, A. M. (1983). Natural contamination of animal feedstuffs with mycotoxins. Agricultural Research Review, 61: 109-123.

9- Abdelhamid, A. M. (1985). Detection of aflatoxins in Egyptian feedstuffs. Annals of Agric. Sci. Moshtohor, 23: 649-657.

10- Abdelhamid, A. M. (1988). Physionutritional effects of rubratoxin-B on rabbits. Arch. Anim. Nutr., Berlin, 38: 825-832.

11- Abdelhamid, A. M. (1988). Effect of sterigmatocystin contaminated diets on fish performance. Arch. Anim. Nutr., Berlin, 38: 833-846 (Aquatic Science and Fisheries Abstract, ASFA).

12- Abdelhamid, A. M. (1989). Contamination of feeding stuffs with mycotoxins and the dangers creating from these contaminants. 1st Meeting on Animal Nutrition, Assuit Univ., Assuit, November, pp: 39-75.

13- Abdelhamid, A. M. (1990). Effect of feeding rabbits on naturally moulded and mycotoxin-contaminated diet. Arch. Anim. Nutr., Berlin, 40: 55-63.

14- Abdelhamid, A. M. (1990). Occurrence of some mycotoxins (aflatoxin ,ochratoxin-A, citrinin, zearalenone and vomitoxin) in various Egyptian feeds. Arch. Anim. Nutr.,Berlin, 40:647-664.

15- Abdelhamid, A. M. (1992). Lights on the toxins and mycotoxicoses in the field of animal production. The 32nd Week of Science, 7-13 Nov., Damascus, Syria.

16- Abdelhamid, A. M. (1993). Decontamination of aflatoxins-contaminated foods by some physical means. J. Egypt. Ger. Soc. Zool., 12 (A): 191-208.

17- Abdelhamid, A. M. (1993). Mycotoxins in local foods and feeds. The 4th Symposium of Food Pollution, Assiut Univ., 15-16 Nov., pp: 46-57 (In Arabic).

18- Abdelhamid, A. M. (1995). Rationalization of the optimum conditions for some mycotoxins separation by thin layer chromatography (TLC). J. Agric. Sci. Mansoura Univ., 20: 201-209.

19- Abdelhamid, A. M. (1995). When the prophylactics are better than the treatment? Al'akhbar, 21 Sep.

20- Abdelhamid, A. M. (1998). Student's biscuit, a quiz without solution. Almesaa, 6 Nov., p:3.

21- Abdelhamid, A. M. (1999). Pollution of fish with heavy metals and mycotoxins. 1st Meeting "Water pollution, its effects on fish and its relation to human health". Ismailia, May 5 (In Arabic), 4 p.

22- Abdelhamid, A. M. (1999). Food borne injuries. Proc. Meeting "Development of rabbits industry and production". Damietta, June 20 (In Arabic), pp: 36-45.

23- Abdelhamid, A. M., (2000). Pollution of aquatic environment. Proc. Meeting "Fish Wealth Development-Principles and Limitations", Mansoura Univ., May 9, pp: 225-233 (In Arabic).

24- Abdelhamid, A.M. (2002). Introduction to the conference book. Proc.2nd Conf. on Food borne Contamination and Egyptian's Health, April 23 - 24, Mansoura Fac. Agric., pp:1-10 (In Arabic).

25- Abdelhamid, A.M. (2004). Aquafeed Quality : Mycotoxins and Mycotoxicoses in Fish .Nutrition in the Management of Aquaculture System, 14-24 June, World Fish Center/ FAO.World Fish Center, Abbassa- Abou Hammad- Sharkia- Egypt.

26- Abdelhamid, A.M. (2005). Mycotoxicoses in fish with special emphasis on the Egyptian situation. Proc. 12th Inter. Con., 19-24 Nov., Al-Hodeidah Univ., Yemen, J. Union Arab Biol. Cairo, 24A( Zoology) : 185 - 214(engormix.com, Mycotoxins Technical Articles, 2007,13 p).

27- Abdelhamid, A. M., and Dorra, T. M. (1990). Study on effect of feeding laying hens on separate mycotoxins (aflatoxins, patulin or citrinin) contaminated diets: on egg quality and tissue constituents. Arch. Anim. Nutr., Berlin, 40: 305-316[cited from Saif Y. M. (2003) Diseases of Poultry, 11th Ed., Iowa State Press].

28- Abdelhamid, A. M. and Dorra, T. M. (1993). Effect of feed-borne pollution with some mycotoxin combinations on broiler chicks. Arch. Anim. Nutr., 44: 29-40[cited from Saif Y. M. (2003) Diseases of Poultry, 11th Ed., Iowa State Press].

29- Abdelhamid, A. M. and Mahmoud, K. I. (1996). Elimination or adsorption of aflatoxin from poultry feedstuffs. Proc. Food Borne Contamination and Egyptian's Health Conference, , Mansoura Univ., 26-27 Nov. , pp: 61-69.

30- Abdelhamid, A. M. and Saleh, M. R. M. (1996). Are aflatoxin and ochratoxin endemic mycotoxins in Egypt ? Proc. Food Borne Contamination and Egyptian's Health Conference, Mansoura Univ., 26-27 Nov. , pp: 51-59.

31- Abdelhamid, A. M. and Saleh, M. R. M. (2000). Effect of graded levels of dietary oxalic acid on growth performance, physiological responses and histological alterations in New Zealand White rabbits. J. Agric. Sci., Mansoura Univ., 25: 4891 - 4903.

32- Abdelhamid, A.M.; Abdel- Khalek, A.E.; Mehrm, A.I. and Khalil, F.F. (2004). An attempt to alleviate aflatoxicosis on Nile tilapia fish by dietary supplementation with chicken-hatchery by-products(egg shells)and shrimp processing wastes(shrimp shells) on : 1 - Fish performance and feed and nutrients utilization. J. Agric. Sci. Mansoura Univ., 29: 6157 - 6173.

33- Abdelhamid, A.M.; Abdel- Khalek, A.E.; Mehrm, A.I. and Khalil, F.F. (2004). An attempt to alleviate aflatoxicosis on Nile tilapia fish by dietary supplementation with chicken-hatchery by-products (egg shells)and shrimp processing wastes (shrimp shells) on : 2 - Clinical, blood and histological parameters. J. Agric. Sci. Mansoura Univ., 29 : 6175 - 6196.

34- Abdelhamid, A.M., Abdel- Khalek, A.E.; Mehrm, A.I.and Khalil, F.F. (2007). An attempt to alleviate aflatoxicosis on Nile tilapia fish by dietary supplementation with chicken-hatchery by-products(egg shells)and shrimp processing wastes (shrimp shells). Aquaculture Technical Articles, Engormix.com, 29 p.

35- Abdelhamid, A.M.; Ahmed, A.M. and El-Melegy, Kh.M. (2002). Detoxification of aflatoxin contaminated diet by some physical and chemical means. J. Agric. Sci. Mansoura Univ., 27: 8213-8224.

36- Abdelhamid, A.M.; Ahmed, A.M. and El-Melegy, Kh.M. (2004). An attempt to alleviate the histological alterations of some internal organs of rats fed on aflatoxin contaminated diets. J. Agric. Sci. Mansoura Univ., 29: 2355-2370.

37- Abdelhamid, A. M.; Arief, H. S. M.; El-Keraby, F. E. and Dorra, T. M. (1995). Effect of some dietary supplements to aflatoxic diets of chickens. II. On the tissues analysis. J. Agric. Sci. Mansoura Univ., 20: 3227-3250.

38- Abdelhamid, A. M.; Dorra, T. M. and Arief, H. A. (1992). Attempts to detoxicate aflatoxin-contaminated-broiler-diet. VIth International Symposium World Association of Veterinary Laboratory Diagnosticians. Lyon, France, June (Abstract).

39- Abdelhamid, A. M.; Dorra, T. M. and Arief, H. S. M. (1995). Effect of some dietary supplements to aflatoxic diets of chickens. I. On the performance. J. Agric. Sci. Mansoura Univ., 20: 3207-3226.

39- Abdelhamid, A. M.; Dorra, T. M.; Mansy, S. E. and Sallam, A. E. (1994). Effect of raising dietary protein, amino acids and/or energy levels as an attempt to alleviate severity of the chronic aflatoxicosis by broiler chicks. I- On the performance and toxicity symptoms. Arch. Anim. Nutr., 46: 339-345 [cited from Saif Y. M. (2003) Diseases of Poultry, 11th Ed., Iowa State Press].

40- Abdelhamid, A. M.; Dorra, T. M.; Mansy, S. E. and Sallam, A. E. (1994). Effect of raising dietary protein, amino acids and/or energy levels as an attempt to alleviate severity of the chronic aflatoxicosis by broiler chicks. II- On the biochemical characteristics. Arch. Anim. Nutr., 46: 347-355.

41- Abdelhamid, A. M.; El-Ayoty, S. A. and Elsaadany, H. H. (1992). The influence of contamination with separate mycotoxins (aflatoxins, Ochratoxin A, citrinin, patulin, penicillic acid or sterigmatocystin) on the dry matter and organic matter digestibilities of some roughages (berseem hay and wheat straw) using in vitro rumen fermentation. Arch. Anim. Nutr., 42:179-185.

42- Abdelhamid, A. M.; El-Ayoty, S. A. and Ibraheem, Z. M. K. (1985). Effect of feeding sheep on concentrate feed mixture containing naturally moulded maize. J. Agric. Sci., Mansoura Univ., 10: 349-357.

43- Abdelhamid, A. M.; El-Mansoury, A.M.; Osman, A.I. and El-Azab, S.M. (1999). Mycotoxins as causative for human food poisoning under Egyptian conditions. J. Agric. Sci., Mansoura Univ., 24: 2751 - 2757.

44- Abdelhamid, A.M.; El-Melegy, Kh.M. and Ahmed, A.M. (2005). Possibility of alleviating foodborne aflatoxicosis effects on performance and biochemistry of male albino white rats. J. Agric. Sci. Mansoura Univ., 30 : 833 - 849.

45- Abdelhamid, A. M.; El-Nashar, E.M. and Saleh, M.R.M.(1999). Effect of subacute ochratoxicosis- A by rabbits. Proc. 15th Ann. Conf. Egypt. Soc. Toxicol., Alex., Oct. 6-7, Vol. 1, pp: 71-85.

46- Abdelhamid, A. M.; El-Shawaf, I.; El-Ayoty, S. A.; Ali, M. M. and Gamil, I. (1990). Effect of low level of dietary aflatoxins on baladi rabbits. Arch. Anim. Nutr., Berlin, 40: 517-537.

47- Abdelhamid, A. M.; El-Shinnawy, M. M. and. Farrag, F. H. H (1990). Effect of feeding sheep on naturally spoiled rice straw, clover hay and concentrate feed mixture. Arch. Anim. Nutr., Berlin, 40: 637-646.

48- Abdelhamid, A. M.; Gabr, A. A. and El-Shinnawy, M. M. (1994). Effect of hydrogen peroxide and urea treatment on chemical composition, cell wall constituents and in vitro organic matter digestibility of rice straw and maize stover. J. Agric. Sci. Mansoura Univ., 19: 3647-3657.

49- Abdelhamid, A. M.; Kandil, W. M.; Arief, H. S. M. and Dorra, T. M. (1995). Effect of some dietary supplements to aflatoxic diets of chickens. III. On the histopathology. J. Agric. Sci. Mansoura Univ., 20: 3251-3259.

50- Abdelhamid, A. M.; Kelada, I. P.; Ali, M. M. and El-Ayoty, S. A. (1992). Influence of zearalenone on some metabolic, physiological and pathological aspects of female rabbits at two different ages. Arch. Anim. Nutr., Berlin, 42: 63-70.

51- Abdelhamid, A.M.; Khalil, F.F.M.; El-Barbary, M.I.; Zaki, V.H. and Husien , H.S. (2002). Feeding Nile tilapia on Biogen^® to detoxify aflatoxic diets. Proc. 1st Ann. Sc. Conf. Anim. & Fish Prod., Mansoura Fac. Agric., 24 & 25 Sep., pp:207-230.

52- Abdelhamid, A. M.; Khalil, F. F. and Ragab, M. A. (1996). Survey of aflatoxin and ochratoxin occurrence in some local feeds and foods. Proceeding of conference on Food Borne Contamination and Egyptian's Health, Mansoura Univ., Nov. 26-27, pp: 43-50.

53- Abdelhamid, A. M.; Khalil, F. F. and Ragab, M. A. (1998). Problem of mycotoxins in fish production. Proc. 6th Conf. of Anim., Poult., and Fish Nutrition. [El-Menia, Nov. 1997. (Abs.) pp: 349 - 350] Egypt. J. Nutr. & Feeds 1(1) 63-71[cited from Encarnaçao, P.(2007) Mycotoxins in Aquaacultyre, www.biomin.net, 8 p].

54- Abdelhamid, A.M.; Magouz, F.I.; Salem, M.F.E.; Mohamed, A.A. and Mohsen, M.K. (2002). Effect of dietary graded levels of aflatoxin B1 on growth performance and biochemical, chromosomal and histological behavior of Nile tilapia, Oreochromis niloticus. Proc. 1st Ann. Sc. Conf. Anim. & Fish Prod., Mansoura Fac. Agric., 24 & 25 Sep., pp:231-250.

55- Abdelhamid, A. M.; Mansy, S. S.; Dorra, T. M. and Sallam, A. E. (1992). Effect of dietary energy, protein and amino acids on broilers fed aflatoxin-B1- contaminated diets. Proc. 3rd World Congress Food borne Infections and Intoxications, Berlin, 16-19 June, pp: 674-677.

56- Abdelhamid, A.M.; Mehrim, A.I. and khalil, F.F. (2004). Detoxification of aflatoxin-contaminated diet of tilapia fish using dietary supplementation with egg shell, Betafin^®, clay or silica. (Proc 1st Egypt.-Syrian Con., 8-11 Dec. 2003, Al-Minia, Abstract) J. Agric. Sci. Mansoura Univ., 29 : 3163 - 3174 (Engormix.com, Technical Articles, 29 p, Sept. 2007).

57- Abdelhamid, A.M.; Ragab, M.A. and El-Shaieb, A.F. (2002). The use of Tafla or aluminosilicate for alleviating toxic effects of aflatoxin-contaminated diets of growing rabbits. Proc.1st Ann. Sc. Conf. Anim. & Fish Prod., Mansoura Fac. Agric., 24 & 25 Sep., pp:389-413.

58- Abdelhamid, A. M., Sadik, E. A. and Fayzalla, E. A. (1985). Preserving power of some additives against fungal invasion and mycotoxin production in stored-crushed-corn containing different levels of moisture. Acta Phytopathologica Academca Scientiarum Hungaricae, 20: 309-320.

59- Abdelhamid, A. M. ; Salem, M. F. I.; Mehrem, A. I. and El-Shaarawy , M. A. M. (2007). Nutritious attempts to detoxify aflatoxic diets of tilapia fish: 1- Fish performance, feed and nutrients utilization, organs indices, residues and blood parameters. Egyptian J. Nutrition and Feeds, 10 (1): 205 - 223. (The 3rd Inter. Conf. on The Environmental & Health Safety, 15-16 Nov. 2006, Mansoura Univ., Abs. Book,p:47 &Aquaculture, Technical Articles, Aquaculture, Technical Articles, Engormix.com,2007, 10 P).

60- Abdelhamid. A.M.; Sallam, A.E.; Abd Allah, G.A. and El-Samra, S.H. (2002). Effect of feeding male rats on aflatoxic diets without or with medicinal herbs (thyme, safflower, ginger, black cumin, and/or garlic). Proc.2nd Conf. on Food borne Contamination and Egyptian's Health, April 23-24, Mansoura Fac. Agric., pp:99-121.

61- Abdelhamid, A.M.; Shabana, Y.M. and Gomaa, S.S.A. (2006). Aquatic fungi and fish production in Egypt. The 2nd Inter. Sci. Con. For Environment "Recent Environmental Problems and Social Sharement", 28-30 March, South Valley University. Pp: 488 - 523.

62- Abdelhamid, A.M.; Shabana, Y.M. and Gomaa, S.S.A. (2007). Aquatic fungi and fish production in Egypt, II- In vitro studies. Aquaculture Technical Articles, Engormix.com, 10 p.

63- Abdelhamid, H. S., A. M. Abdelhamid, M. Ezzat, and M. A. Akeila (1989). Studies on mycoflora of poultry feeds with special emphasis to aflatoxin production. 3rd Egypt. British Conf. on Animal, Fish and Poultry Production. Alexandria, 7-10 October, pp: 933-941.

64- Ali, M. M., A. M. Abdelhamid, E. Elansary, and A. H. Raya (1984). The effect of ochratoxin-A on some metabolic and physiological aspects in pigeons. Assiut J. of Agric. Sci., 15: 119-129.

65- Böhm, J., GH. Noonpugdee, A. M. Abdelhamid, J. Leibetseder, und M. Schuh (1985). Zearalenon (F-2 Toxin)-Das Vorkommen eines östrogenwirksamen Mykotoxins in Österreich, beobachtet über den Zeitraum von 1979 bis 1984 in Zusammenhang mit Fruchtbarkeitsstörungen bei Rind und Schwein. Die Bodenkultur, 36: 333-338.

66- Kandil, W. M., S. M. Sirag, A. M. Abdelhamid, and T. M. Dorra (1991). Histopathological studies on mycotoxicoses in broiler chicks. Mansoura Medical Journal, 21: 193-204.

67- Leibetseder, J., A. M. Abdelhamid, and CH. Noonpugdee (1985). Nature occurrence of mycotoxins in Austria. Sixth International Symposium on Mycotoxins and Phycotoxins. IUPAC, Pretoria, Republic of South Africa, 22-25 July (Edited by P. S. Steyn and R. Vleggaar, Elsevier, Amsterdam, Oxford, New York, Tokyo, 1986).

68- Mahmoud, K. I., A. M. Abdelhamid, and A. Mandour (1994). In vitro and in vivo comparative studies on the efficacy of some aflatoxin-detoxifying agents. Alex. J. Vet. Science, 10: 39-47.

69- Mansy,S. E., A. M. Abdelhamid, T. M. Dorra, and A. E. Sallam (1993). Synergism between low level aflatoxin and different supplements in diet of broiler chicks. Variation in hematological and immunological parameters. The 4th Symposium of Food Pollution, Assiut Univ., 15-16 Nov., pp: 63-79.

70- Mehrim, A. I.; A. M. Abdelhamid, A. A. M. Abo Shosha, M.F.I. Salem and M.A.M.M. El-Sharawy (2006). Nutritious attempts to detoxify aflatoxic diets of tilapia fish: 2- Clinical, biochemical and histological parameters. J. Arab. Aqua. Soc., 1 (2) : 69 - 90 (Aquaculture, Technical Articles, Engormix.com, 2007, 12 P).

71- Noonpugdee, GH., J. Böhm, A. M. Abdelhamid, J. Leibetseder, und M. Schuh (1986). Über des Vorkommen von Desoxynivalenol (Vomitoxin, DON) in Futtermitteln für österreichische Nutztierbestände im Zeitraum von 1979 bis 1985. Die Bodenkultur, 37: 87-94.

72- Schweighardt, H., A. M. Abdelhamid, und J. Leibetseder (1980). Über Vorkommen und Nachweis der Fusariotoxine Zearalenon und Vomitoxin in Österreich. In: Kurzfassungen der Vorträge zur 34. Tag. Ges. Ernährungsphysiol. Haustiere, Göttingen, 13. Z. Tierphysiol. Tierernährug u Futtermittelkde., 44: 7-8.

73- Schweighardt, H., J. Böhm, A. M. Abdelhamid, und J. Leibetseder (1980). Analysis of the fusariotoxins zearalenone and vomitoxin (deoxynivalenol) in human foods and animal feeds by high performance liquid chromatography (HPLC). Chromatographia, 13: 447-450.

74- Schweighardt, H., M. Schuh, A. M. Abdelhamid, J. Böhm und J. Leibetseder (1980). Methode zur Ochratoxin-A-Bestimmung in Lebens-und Futtermitteln mittels Hochdruckflüssigkeits-chromatographie (HPLC). Z. Lebensm. Unters. Forsch., 170: 355-359[cited from Valenta, H. (1998) Review chromatographic methods for the determination of ochratoxin A in animal and human tissues and fluids. J.Chromatography A, 815: 75 - 92].