(2) Staphylococcus aureus food poisoning Staphylococcus aureus exotoxin and enterotoxin. This bacterium can produce six different antigens of soluble protein enterotoxin A, B, C, D, E and F at a suitable temperature. This enterotoxin is very heat-resistant, only 2 18? 248℃, 30 minutes to eliminate, eliminate toxicity. Milk and dairy products, bacon, eggs and starchy foods are easily contaminated by bacteria.
(3) E.coli, a conditional pathogen of food poisoning, is a normal flora in the intestine and a serotype strain with specific antigens of E.coli. Among the three antigens, E.coli bacterial antigen (O), flagella antigen (H) and capsular antigen (K) are more malicious than KK antigen. K antigen can be divided into three categories: A, B and L. Conditional pathogens that can cause food poisoning include O11:B4o55: B5o26: B6O157 and other serotypes.
(4) Vibrio parahaemolyticus food poisoning Vibrio parahaemolyticus is a gram-negative coccidia with halophilic spores. Seafood and meat contaminated by Vibrio parahaemolyticus are common, and other foods may also be contaminated by seafood. Food poisoning is caused by bacteria producing heat-resistant hemolytic toxin, which is similar to cholera enterotoxin, toxin or mixed infection.
Clostridium botulinum (5) The food poisoning caused by botulinum can form Gram-positive bacteria with spores, no capsules and no flagella, and can produce a strong toxic exotoxin botulinum toxin A for humans and animals. People who can be divided into seven serotypes, A, B, C(α, β), D, E, F and G, have different virulence. Botulinum toxin is quite unstable under high temperature and alkaline conditions, but more stable under acidic conditions. Toxins causing toxic botulinum toxin poisoning act on the central nervous system and brain nuclei, inhibit the release of acetylcholine, and lead to muscle paralysis. In anaerobic soil, rivers and lakes, sludge deposition, dust and animal manure are common, and vegetables, fish, meat, beans and other foods rich in protein are easily polluted.
(6), Bacillus cereus food poisoning spores of Gram-positive Bacillus cereus, poisoning is caused by a large number of enterotoxins caused by live bacteria food, and the number of surviving cells reaches (13? 36)× 10 6/g (ml) can be caused by pathogens. Usually, the bacterial content (1.8× 10 7)/ ml (g) is one of the indicators of food poisoning. Enterotoxin can be divided into heat-resistant type and heat-resistant type. Bacteria exist in soil, air, decaying vegetation, dust, meat products, dairy products, vegetables, fruits and other places with high carrier rate. Bacteria are also easily contaminated during processing, transportation, storage and sales.
(8) Mycotoxin food poisoning caused by a few mycotoxins. A species or strain can produce several different toxins, and the same toxin may also be different molds. All kinds of pollution are mainly Aspergillus and Penicillium. The main polluted meat is powdery mildew (Thamnidium nematodes) and Mucor elegans (Mucor elegans), and the main polluted feed is Aspergillus, Penicillium and Cladosporium (freckles).
(9) Aflatoxin poisoning (aflatoxin) Aflatoxin and Aspergillus A.parasiticus produce a class of metabolic mixed products with similar structures, with more than 17 kinds. Its basic structure is two furan rings and coumarin, the former is alkaline toxic structure and the latter is carcinogen. Aflatoxin is very stable, heat-resistant and will not break the melting point (200℃? 300℃), its toxicity is very strong, which mainly damages the liver, liver necrosis, bleeding, bile duct hyperplasia and carcinogenesis. Production of food contaminated by mold and aflatoxin and its products, peanut, peanut oil, rice, cottonseed, milk, salted fish and other pollution.
(10) Wheat scab poisoning (trichosporene poisoning) Wheat scab poisoning is food poisoning caused by eating wheat scab. Fusarium graminearum, Fusarium headsight, Fusarium moniliforme and f.avenaceum caused wheat scab. They can produce two types of mycotoxins, and scabbed wheat zearalenone toxin can cause vomiting and estrogen effects.
(1 1) yellow rice poisoning (yellow wheat poisoning), the beige color of grain contaminated by fungal metabolites, is called yellow rice. According to the contaminated mold, it can be divided into three types, namely, the yellow-beige Pseudomonas turns yellow-beige, and its main body produces yellow-green mold (Pseudomonas aeruginosa) CIT (Penicillin citricola), which is highly toxic to human nerves and can lead to death. The second is through citrus (P. citrinum), orange-green toxin Huang Qing mold rice and toxin pollution (Citrin), which mainly damages the kidneys and causes great damage. The third Penicillium islandicum turns yellow into rice, and the toxin of Penicillium islandicum (luteoskyrin) and the toxin of Penicillium islandicum (islanditoxin) poison the liver and cause pollution.
(12) ergot poisoning (ergot poisoning) is caused by eating wheat or wheat products and ergot. When the pathogenic microorganism ergot (ergot chrysanthemum) is used, bacteria can form three alkaloids, ergotamine, ergotamine and ergonovine, and ergotamine can cause food poisoning, acute nausea, vomiting, abdominal pain, diarrhea, heart failure, coma and chronic symptoms.
(13) Toxic fungal metabolites of food poisoning caused by sugarcane mildew poisoning.
(14), anthrax and anthrax bacteria can cause anthrax, abdominal pain, vomiting and bloody stool after eating the meat of dead animals. When pathogens enter the blood, it is easy to form systemic septicemia. Brucellosis in cattle and pigs can also cause human diseases. Mycobacterium tuberculosis is a pathogen that both humans and animals suffer from. Cattle are prone to tuberculosis, and mycobacterium tuberculosis often suffers from breast diseases.
Production characteristics of mycotoxin
1) is limited to a small number of mycotoxin strains, and mycotoxin production and strain toxin production are only a part of it.
2) The toxin-producing strains also showed variability and variation. Toxin-producing strains can completely lose the ability of toxin-producing strains to produce toxins after culture under certain conditions. Therefore, this problem should be considered at any time in practical work.
3) A species or strain can produce several different toxins, and the same mycotoxin can also be produced by several molds.
4) The toxin-producing strains need certain conditions, such as substrate type, humidity, temperature, humidity and air circulation.
Aspergillus (black)
Aspergillus mycelium, hyphal septum, multicellular. Conidia propagate asexually, conidiophore has no branches, and the top is spherical or rod-shaped with a apical sac. The top capsule radiates one or two layers of peduncle, and the original string conidia at the top of the peduncle have different colors, such as black, brown, yellow and so on. Ascomycetes, Ascomycetes and Ascomycetes Spores of Sexual Generation Aspergillus with Closed Capsules. Aspergillus is widely distributed in nature and has a strong ability to decompose organic matter. Aspergillus, such as some species of Aspergillus Niger, has been widely used in food industry. Aspergillus is an important food contamination mold, which will cause food deterioration, and some strains will also produce toxins. Aspergillus species can produce toxins, such as aflatoxin (Aspergillus flavus), Aspergillus versicolor (Aspergillus versicolor), Aspergillus fumigatus, Aspergillus nidulans (Aspergillus nidulans) and Aspergillus parasitica (Aspergillus parasitica).
3.2.2 Penicillium (Penicillium)
Penicillium filaments are colorless or light-colored, multi-branched and septate. From mycelium to conidia diaphragm, 1? A branch after the second time, these branches are called secondary branches and stems. There are many petioles on the stems, and the structure of broom-like spores produced at the top of the petioles is called. Conidia may have different colors, such as blue, gray, green and brown, and the single wheel is a spiral symmetric and asymmetric wheel broom. Only a few species can form closed cysts, while Penicillium produces ascospores. Penicillium is widely distributed and has a wide variety, which often exists in soil and food, as well as in fruits and vegetables. Some species have high economic value and can produce various enzymes and organic acids. On the other hand, Penicillium can cause spoilage of fruits, vegetables, grains and foods, and some varieties and strains can also produce toxins. Such as Penicillium (P.islandicum), Penicillium citrinum (P.citrinum), Penicillium luteum (P.citreo Trichoderma viride) (Penicillium rubrum), Penicillium rubrum, Penicillium rotundum (P.expansum), Penicillium pure (P.patulum) and Penicillium obliquus.
3.2.3 Fusarium
Developed or underdeveloped belong to aerial hyphae. There are three to seven kinds of conidia, which produce short claw-like processes of hyphae or mucinous spores of various shapes, such as sickle and spindle. The microspore chamber of 1 2 produces conidia, ovoid, ovoid, etc. The aerial hyphae, myxospore bases and sclerotia can be in the form of various colors, and the matrix is dyed in various colors. many
Fusarium species, most of which are plant pathogens, can produce toxins. (Fusarium graminearum), Kentucky bluegrass with Fusarium trifoliate, broom, broom, Fusarium equisetum and Fusarium pink without cigar blight.
3.2.4 Cross-linked Mortierella Alternaria
The creeping conidiophore is short, simple or massive, and most unbranched hyphae have septa. The growth conidia at the top of conidia are variable in shape and size, including mulberry, oval and ovoid, with longitudinal direction on it.
Diaphragm form, beak-shaped at the top, with many cells protruding. Spores are brown and fixedly connected into chains. No sexual generation was found.
Neurospora crassa is widely distributed in soil and air, and some plant pathogens can cause fruits and vegetables to rot and produce toxins.
In the case of 3.2.5.
Trichoderma. And auricularia auricula are mildew-proof paint spots.
3.3 Main mycotoxins
3.3. 1 aflatoxin
Aflatoxin is a metabolite of Aspergillus flavus and Aspergillus parasiticus. All parasitic Aspergillus strains can produce aflatoxin, but we are rare parasitic Aspergillus. Aflatoxin is a common fungus in food and feed in China. Because of its strong carcinogenicity, it has attracted much attention. However, even under the environmental conditions that produce toxins, not all strains that produce aflatoxins must be suitable.
3.3. 1. 1 aflatoxin
The chemical structure of aflatoxin is dihydrofuran and oxynaphthone. B 1, B2, G 1, G2, B2A, G2A, M 1, M2, P 1. B 1 has the strongest toxicity and carcinogenicity, and its toxicity is more than 0/00 times that of potassium cyanide/kloc-0. Post-botulinum toxin is the strongest mycotoxin, and its carcinogenicity is 75 times stronger than that of known chemical carcinogens and dimethylnitrosamine. Aflatoxin has the characteristics of heat resistance, its thermal decomposition temperature is 280℃, its solubility in water is low, and it is soluble in fat and various organic solvents.
3.3. 1.2 Toxin production conditions of aflatoxin
The temperature range of aflatoxin produced by Aspergillus flavus growth is 12? 42℃, the optimum toxic temperature is 33℃, and the optimum Aw value is 0.93? 0.98。 Aflatoxin increased by 18.5%. Aflatoxin was produced by corn, rice and wheat on the third day, reached the peak on the tenth day, and then gradually decreased. The products of hyphotoxin formed by bacterial spores are gradually discharged into the matrix. The delayed production of aflatoxin refers to foods with high water content. If it is used within two days, the water content of grain will be reduced to below 13%, and aflatoxin will not be produced even if it is polluted.
Aflatoxin pollution may occur in various foods, such as grains, oilseeds, fruits, dried fruits, spices, milk and dairy products, vegetables and meat. Including corn, peanuts and cottonseed oil, are the most vulnerable to pollution, followed by rice, wheat, barley, beans and so on. Strains producing aflatoxin in peanuts, corn and other grains grow normally and produce aflatoxin matrix. Aflatoxin pollution in peanuts and corn before harvest not only pollutes the mature peanut aflatoxin, but also may be separated from the toxin and the mature corn ear, which can not only detect aflatoxin and aflatoxin.
Table 8- 1 National Allowable Limits of Aflatoxin in Food and Feed
Food and feed aflatoxin B 1 limit microgram/kg Remarks
China corn peanut, peanut oil, rice and edible oil food, bean fermented food and baby food < 20 <10 <; Health standards in 50 countries
All foods and feeds in Japan 002040 Chickens, calves, piglets, cows, domestic animals and poultry BR/> General food peanut food peanut with shell 201525b1b2g1g2 Total b1b2g1g2b/kloc-.
French food feed 050200 sheep, goats, adult sheep, adult pigs, chickens, cows and other livestock and poultry.
German food and feed 10
Aflatoxin mainly produces B 1 and B2, so the determination of aflatoxin content in B 1 is more important. Aflatoxin is much more toxic, carcinogenic and widely distributed, which poses a great threat to human beings and animals. Therefore, the state has formulated the maximum allowable dose in food and feed (Table 8- 1).
Epidemiological investigation of liver cancer, incidence of liver cancer in human body area, actual intake of aflatoxin pollution in food.
3.3.2 Yellow rice toxin
Yellow rice was discovered in Japan in the 1940s. This fungus pollutes yellow rice, so it is called yellow rice. Rice fungi that can cause yellowing are mainly some species of Penicillium. Yellow rice toxin can be divided into three categories:
3.3.2. 1 Penicillium flavum toxin
14.6% of rice moisture is infected with Pseudomonas aeruginosa, which can form 12? /kloc-yellowing at 0/3℃ produces yellow spots on a grain of rice, producing Penicillium chrysogenum toxin (penicillin flavomycin). The toxin is insoluble in water, and loses its toxicity when heated to 270℃. The central nervous system characterized by neurotoxic poisoning paralyzes the heart and body, and finally dies of respiratory arrest.
Penicillium citrinum toxin in 3.3.2.2
The rice polluted by orange turns yellow, and the rice grains form yellow-green Penicillium. White rice is easily polluted by oranges and forms yellow rice. Penicillium and Penicillium citri can produce toxin (orange), and so can Penicillium deep blue, Penicillium yellowish green, Penicillium punctatum, Penicillium cinerea and Aspergillus. Toxin is insoluble in water, which can cause kidney, toxin, renal tubular dilatation, epithelial cell degeneration and necrotizing nephromegaly in experimental animals.
Penicillium insulatum was formed after Penicillium 3.3.2.3 and Penicillium toxin.
The yellow rice polluted by the island is a beige ulcerative lesion, and it also contains toxins produced by Penicillium islandicum, including Huang Tianjing, ciprofloxacin, Island Penicillin and refined Red Sky Red. The first two toxins are hepatotoxic, and acute poisoning can lead to atrophy of animal liver; Chronic poisoning, liver fibrosis, cirrhosis or liver tumor can all lead to liver cancer in rats.
fusarium toxin
At the third joint meeting of food additives and pollutants held by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO), Fusarium toxin and aflatoxin were regarded as the same naturally occurring and most dangerous food pollutants. Toxins produced by Fusarium. Fusarium is widely distributed in nature and infects many crops. Many kinds of Fusarium can produce huge Fusarium toxin, which poses a threat to human and animal health. More than a dozen Fusarium toxins have been found, which can be divided into the following three categories. According to their chemical structures, monoterpenes, zearalenone and crotonolide.
3.3.3. 1 trichosporene
Fusarium toxin produced by Fusarium oxysporum, Fusarium graminearum, Fusarium pyriformis and Fusarium pseudofilum. It is caused by human and animal poisoning and is the most common type, Fusarium toxin.
Deoxynivalenol (DON) is commonly found in Trichosporon compounds in our food and feed. DON mainly exists in wheat, corn, rice, beans and other crops, which can infect scabies and contain DON. The pathogen of scab is Fusarium graminearum (G.zeae), the asexual stage of Fusarium graminearum. This pathogen is suitable for growth and reproduction in rainy, high humidity and low temperature climate conditions. If a wheat is infected at the milk maturity stage, the mature grain will shrink, shrivel and become gray-pink and moldy. For example, the infected grain image in the later stage is all pink, but the embryo. DON, also known as emetic toxin, is soluble in water and has high thermal stability. Baking temperature is 2 10℃, frying temperature is 140℃ or boiling, which can only destroy 50%.
People who eat DON-containing crusted wheat (including 10% diseased wheat flour 250g) will have symptoms such as nausea, dizziness, abdominal pain, vomiting, general fatigue, etc., mostly within one hour. A few patients were accompanied by diarrhea, facial flushing, headache and other symptoms. Feed sick wheat to pigs, and pigs gain weight slowly. Autopsy report fat khaki, hepatobiliary bleeding. The oral dose of Tang dog emetic is 0.65438 0 mg/kg.
Zearalenone in 3.3.3.2
Zearalenone is a female estrus toxin. The feed that animals eat contains this toxin, and female estrus syndrome will appear. Xanthomonas campestris, Fusarium graminearum, Fusarium pink, Fusarium tricuspidatum and Fusarium equisetum can all produce zearalenone. about
Zearalenone is insoluble in water, but soluble in alkaline aqueous solution. Inoculate Gibberella zeae at 25℃. After two weeks at 28℃ and eight weeks at 65438 02℃, a large amount of zearalenone was obtained. Wheat scab may sometimes contain DON and zearalenone. 1 ~ 5mg/kg feed contains zearalenone, and the content is 500mg/kg when symptoms appear obviously. Zearalenone can also be detected in corn.
3.3.3.3 crotonic lactone (crotonic lactone)
Feeding cattle infected with crotonolide feed with pasture. Rotten foot disease is found in nature. The research center of Kashin-Beck disease of Harbin Medical University reported that butenolide exists in the corn yield of Kashin-Beck disease in Heilongjiang and Shaanxi provinces. Butenolactone is one of Fusarium of Fusarium oxysporum and Pyricularia of Fusarium oxysporum, which is easily soluble in water and easily hydrolyzed in alkaline aqueous solution.
3.3.4 Aspergillus versicolor poisoning
The basic structure of a pair of furan rings and an xanthone produced by Aspergillus versicolor, Aspergillus nidulans and Aspergillus versicolor toxin. Aspergillus versicolor toxin IVA is the most toxic, insoluble in water, which can cause liver cancer, renal cell cancer, skin cancer and lung cancer in animals, and its carcinogenicity is second only to aflatoxin. Aspergillus versicolor and Aspergillus nidulans are often contaminated by food, and more than 80% of the strains produce toxic Aspergillus versicolor toxin, which is very important in the etiological study of liver cancer. Brown rice is easily contaminated by aspergillus versicolor toxin, and the toxin content can be reduced by 90% after brown rice is processed into standard two meters.
3.3.5 Aspergillus fuscus toxin
Aspergillus fuscus toxin, Aspergillus fuscus and Penicillium. It was identified as two types of aspergillus fuscus toxin A and aspergillus fuscus toxin B, which can cause visceral diseases such as liver in many animals when dissolved in alkaline solution. They are called hepatotoxins or nephrotoxins, but they can also cause lung diseases.
Aspergillus fuscus produces toxins in suitable substrates such as corn, rice and wheat. The suitable temperature for toxin production is 20? At 30℃, the Aw value is 0.997 to 0.953. Aspergillus Niger toxin A can sometimes be detected in food and feed.
Show penicillin toxin
Penicillin toxin is mainly composed of Penicillium, which is easily soluble in water and ethanol and easily destroyed in alkaline unstable solution. Pollution of Penicillium cattle feed can cause poisoning, and mice poisoned by Penicillium toxin have severe edema. Penicillium toxin produces a large amount of wheat straw.
Penicillium Mali pumilae stores important mildew fungi, which can rot apples. The apple juice produced by this rotten apple contains spread mycotoxin. Penicillium toxin in rotten apple juice can be reduced to 50% and up to 20? 40 micrograms per liter,
about
Acids produced by molds such as penicillic acid, Penicillium brownii, Penicillium arc and Aspergillus (penicillic acid). Soluble in hot water and ethanol. 1.0mg penicillic acid was injected subcutaneously for 2 weeks, and local fibroma had mutagenic effect on mice 64 ~ 67 weeks after injection. examination
Corn, barley, beans, wheat, sorghum, rice, malic acid. Penicillic acid is formed below 20℃, which may pollute food, mildew and refrigerate cyanic acid.
Alternaria toxin
Alternaria alternata is one of the common molds in food, fruits and vegetables, and many fruits and vegetables may lead to corruption. There are four kinds of toxins produced by Alternaria alternata: Alternaria alternata (AOH Alternaria), Alternaria alternata methyl ether (AME Alternaria methyl ether), Alternaria alternata and olefine azo acid (theafine azo acid). AOH and AME are teratogenic and mutagenic. After oral administration in mice or rats, 50? 398mg/kg tea sodium salt can cause gastrointestinal bleeding and die. Alternaria toxin produces low-level acute poisoning in nature, and generally does not cause human or animals. However, in the detection of human mycotoxin poisoning in tomato and tomato sauce tea, its chronic toxicity deserves attention.
Generally speaking, mycotoxin strains in cereals, fermented foods and feed will produce toxins, but it is rare to produce toxins directly in animal foods such as meat, eggs and milk. Animals that eat a lot of toxic feed can also cause poisoning symptoms or remain in animal tissues and organs. Intake of toxic substances in milk and animal food will still cause mycotoxin poisoning.
The eating habits, various foods and living environment conditions of mycotoxin poisoning people often show obvious locality and seasonality, and even some endemic diseases. Such as aflatoxin poisoning, yellow rice poisoning and scab wheat poisoning all have this characteristic. In addition, the clinical manifestations of mycotoxin poisoning are more complicated, and acute poisoning can occur. Chronic poisoning caused by a small amount of food intake for a long time contains mycotoxins, as well as some substances that induce cancer, lead to physical deformity and genetic mutation.
Food contaminated by mold and mycotoxin, especially in the world, is very harmful to human beings, which not only causes huge economic losses, but also may lead to serious diseases and even a large number of deaths. Don't eat moldy food containing mycotoxin, which can greatly reduce the incidence of cancer and avoid the occurrence of cancer.
The survival of microorganisms in a large number of agricultural products, especially food. According to the relevant data, it can be divided into protozoan flora and temporal endogenous flora. Protozoan microflora microorganisms and plants have formed a long-term cooperative relationship, and the life span of seed exudates is closely related to the life span and metabolic intensity of plants. Endophytic microbial flora of the era exists in microbial infections of soil, air and food in many ways. Food microorganisms, especially molds, are seriously harmful and can produce harmful mycotoxins to 150 kinds of humans and animals.