Nemanja Todorović, Marko Vasiljević, Jog Raj, Hunor Farkaš, and Zdenka Jakovčević
PATENT CO,. Mišićevo, Serbia
Fumonisins are a significant health risk to livestock and potentially also to humans
Fumonisins are naturally occurring toxins produced by several species of Fusarium fungi (molds), with Fusarium moniliforme recognized as the largest producer of this mycotoxin. Other species such as F. proliferatum, F. nygamai, F. anthophilum, F. dlamini and F. napiforme are also producers. Only Fumonisin B1 (FB1), B2 (FB2) and B3 (FB3) are toxicologically significant whereas the most predominant FB1 corresponds to 70% of fumonisins. In comparison to other mycotoxins, fumonisins are highly soluble and have greater capacity to spread easily and contaminate high volume of water and feedstus. FB1 is classified as a potential human carcinogen (class 2B) by International Agency for Research on Cancer (IARC) and has been linked to acute toxicity in farm animals (horses and swine), including hepatotoxicity and nephrotoxicity.
Fumonisins are naturally occurring toxins produced by several species of Fusarium fungi (molds), with Fusarium moniliforme recognized as the largest producer of this mycotoxin. Other species such as F. proliferatum, F. nygamai, F. anthophilum, F. dlamini and F. napiforme are also producers.
Only Fumonisin B1 (FB1), B2 (FB2) and B3 (FB3) are toxicologically significant whereas the most predominant FB1 corresponds to 70% of fumonisins. In comparison to other mycotoxins, fumonisins are highly soluble and have greater capacity to spread easily and contaminate high volume of water and feedstus. FB1 is classified as a potential human carcinogen (class 2B) by International Agency for Research on Cancer (IARC) and has been linked to acute toxicity in farm animals (horses and swine), including hepatotoxicity and nephrotoxicity.
Raw materials affected
FB1 and FB2 can be found as a natural contaminant in cereals, specially corn and wheat, usually in concentrations that generally induce subclinical intoxications in different species.
Fungi of Fusarium genus are widespread worldwide and are the cause of economically significant diseases of cultivated and other plants called FUSARIOSIS. It can be found in grains e.g corn, wheat, etc. In wheat, this disease can cause yield reductions of up to 70%.
Corn micotoxinas survey 2018
Fumonisins are found globally in grains and other feed materials. Recent mycotoxins survey conducted by PATENT CO shows that corn harvested around the world in 2018 and 2019 is mostly contaminated with fumonisins. In 2018 fumonisins were present in most of the samples (78%) with a median of 668 ppb and a total of 95% corn samples were contaminated with one or more mycotoxins.
Corn mycotoxins survey 2019
Fumonisins were detected in 82 % of samples, DON in 27%, AFB1 in 9%, T-2/HT-2 in 12% and ZON in 17 % of samples from the various countries.
The toxic effects of fumonisins are essentially the result of inhibiting sphingolipids synthesis (lipoprotein such as sphinganine and sphingosine), which controls cellular communication. The fumonisins are structurally similar to sphingosine, which forms a primary part of sphingolipids, a class of cell membrane lipids that include sphingomyelin, an important phospholipid. Fumonisins inhibit the sphinganine (sphingosine) N-acyltransferase (ceramide synthase), a key enzyme in lipid metabolism, resulting in disruption of this pathway.
Fumonisin’s toxicity to animals
The clinical signs associated with fumonisins’ toxicity vary significantly between species. This effect is dependent on primary target organ as safe levels of Fumonisins in feed are different for all animal species.
FUMONISINS ARE SEVERE IMMUNOSUPPRESSANTS AT VERY LOW CONCENTRATIONSS
Typical mycotoxin induced symptoms are usually correlated with acute intoxications. However, another important fact is that Fumonisins impair immune response in many ways. Following oral intake of low amounts of these mycotoxins, firstly, the gastro-intestinal epithelial cell layer is exposed to these toxins. Fumonisins alter the different intestinal defense mechanisms including epithelial integrity, cell proliferation, and cytokine production. Since the intestinal tract is a major entrance to many enteric pathogens and their toxins, mycotoxin exposure can result in a greater susceptibility to enteric infections in animals consuming feed contaminated with these toxins.
Horses – extremely sensitive
Fumonisins can be extremely harmful to horses. When present in corn or other grains, fumonisins can result in moldy corn poisoning or leukoencephalmalcia. The disease syndrome was named Leukoencephalomalacia due to the type (malacia = softening [due to necrosis]) and distribution (leuko = white matter) of the most prominent lesion in the brain. Equine are the only species in which fumonisins induce this lesion.
Feed manufacturers selling corn or horse feed containing corn should consider testing to ensure that the feed is safe for horses. The presence of fumonisins should alert feed manufacturers to monitor ingredients, especially corn, and evaluate the level of corn in horse feeds.
Numerous studies showed that acute fumonisins’ toxicity in swine is linked with pulmonary edema which generally occurs between 3 and 5 days after the initial consumption of contaminated feed.
Swine chronically intoxicated with FB1 and FB2 even at low dose shows nonspecific clinical symptoms such as reduction of daily feed consumption and body weight gain, lower feed conversion rate and carcass quality, associated with hepatic lesions and overall sickly appearance of the animal..
Necropsy of swine intoxicated with high doses of fumonisins have shown the occurrence of pulmonary edema which frequently evolves into hydrothorax. The lungs of pigs affected by pulmonary edema did not collapse when removed from the chest, and they increased in size with rounded edges.
The most important immunosuppressive effects of fumonisins in poultry are:
- ⇰ Reduced thymus weight
- ⇰ Reduced immunization against Newcastle disease
- ⇰ Reduced macrophage numbers
- ⇰ Decreased phagocytic ability of macrophages, leading to increased susceptibility to bacterial infections
- ⇰ Decreased total white blood cell counts
- ⇰ Induces thymic cortical thinning, mild bursal follicular atrophy and mild splenic lymphocyte depletion
- ⇰ Decreased lymphocyte response to Salmonella gallinarum infection
Gross and histopathological lesions, as well as changes in serum enzymes and biochemistry indicate an impairment of liver and possibly kidney function. Although fumonisin is poorly absorbed and metabolized by cattle, it induces disturbances in the gastrointestinal tract.
INVISIBLE LOSSES – SUBCLINICAL EFFECTS
Nonetheless, a more likely scenario is to find mycotoxins at lower levels interacting with other stress factors leading to subclinical losses in performance, increase in incidence of disease and reduced reproductive performance. For the farmers, these subclinical losses are of greater economic importance than losses from acute effects, which are even more difficult to diagnose.
⇰ They grow on a variety of different crops and foodstuffs including cereals, nuts, spices, dried fruits, apples and coffee beans, often under warm and humid conditions.
⇰ According to FAO, at least 25% of the world’s food crops are contaminated with mycotoxins, at a time when the production of agricultural commodities is barely sustainable.