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Mold is a common name for filamentous fungi, which means "moldy fungi". They tend to form lush mycelium, but they don't produce large fruiting bodies like mushrooms. In wet and warm places, many objects will grow fluffy, flocculent or cobweb-like colonies visible to the naked eye, that is, mold; Bio-Rad Aspergillus antigen detection kit (PlateliaTM Aspergillus Ag) is widely used for Aspergillus detection. [ 1]
Introduction of mould
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Mould (mould)
Mold is a general term for fungi that form branched hyphae. It is not a taxonomic term, but it belongs to various subfamilies of fungi in classification. The basic unit of the phantom is called mycelium, which is long and tubular, with a width of 2 ~ 10 micron, and can continuously grow and branch from the front end. Septum or septum, with 1 to multiple nuclei. The cell wall is divided into three layers: the outer layer is amorphous β -glucan (87 nm); The middle layer is glycoprotein, and the middle of the protein net is filled with dextran (49 nm); The inner layer is chitin microfiber containing amorphous protein (20nm). When growing on a solid substrate, some hyphae go deep into the substrate to absorb nutrients, which are called substrate hyphae or vegetative hyphae; The aerial hyphae extending into the air can further develop into reproductive hyphae and produce spores. A large number of hyphae are interwoven into fluffy, flocculent or reticulate, which is called mycelium. Mycelia is usually white, brown, gray or bright (Mucor is a white hairy colony, Penicillium is green, Aspergillus flavus is yellow), and some can produce pigments to color the substrate. The rapid propagation of mold often leads to a large number of moldy deterioration of food and utensils, but many beneficial species have been widely used, and they are the earliest used and recognized microorganisms in human practice.
Mold is a common name for filamentous fungi, which means "moldy fungi". They tend to form lush mycelium, but they don't produce large fruiting bodies like mushrooms. In wet and warm places, some plants grow on many things. The fluffy, flocculent or cobweb colony visible to the naked eye is mold. Its cell wall is mainly composed of chitin, which should be distinguished from Streptomyces.
Mould under microscope (4 photos)
Characteristics of mould colony:
A, the shape is large, the texture is loose, the appearance is dry and opaque, and it is loose or tight.
B, the colony is closely connected with the culture medium, and it is not easy to pick. The color and structure of the front and back of the colony, as well as the color and structure of the edge and center are often inconsistent.
C, the hyphae of mold have the differentiation of vegetative hyphae and aerial hyphae, while aerial hyphae have no capillary water, so its colony must be different from bacteria or yeast and closer to actinomycetes.
The mycelium of mold. The basic unit that constitutes the vegetative body of mold is mycelium. Mycelium is a kind of tubular filament, which looks like a transparent hose when observed under a microscope. Its diameter is generally 3 ~ 10 micron, which is several times to dozens of times thicker than the cells of bacteria and actinomycetes. Mycelium can elongate branches, and many branches of mycelium are intertwined, which is called mycelium.
According to whether there is a diaphragm in the mycelium, mold mycelium can be divided into two types: diaphragm-free mycelium and diaphragm mycelium. Diaphragm-free mycelium has no diaphragm, and the whole mycelium is a single cell with multiple nuclei. This is the mycelium type of lower fungi. There is a diaphragm in the diaphragm mycelium, and a section of mycelium separated by the diaphragm is a cell. Mycelia is composed of many cells, and each cell has 1 or more nuclei. There are 1 to many pores on the diaphragm, so that the cytoplasm and nutrients between cells can communicate with each other. This is the mycelium type of higher fungi.
In order to adapt to different environmental conditions and absorb nutrients more effectively to meet the needs of growth and development, the hyphae of many molds can differentiate into some special shapes and tissues, which is called mycelium metamorphosis.
Mold hyphae growing on solid medium can be divided into three parts: ① vegetative hyphae: hyphae that absorb nutrients in deep medium; (2) aerial hyphae: hyphae with nutritious hyphae growing into the air; ③ Reproductive hyphae: Some aerial hyphae develop to a certain stage and differentiate into reproductive hyphae to produce spores.
Haustorium: Metamorphosis of hyphae caused by specific parasitic fungi such as rust, downy mildew and powdery mildew, which is a lateral branch produced by hyphae, invades cells, differentiates into roots, fingers, balls and bergamot, and absorbs nutrients in host cells.
Rhizomatous stem: Rhizopus mycelium contacts with nutrient matrix to form rhizomatous structure, which has the function of fixing and absorbing nutrients.
Bacterial nets and rings: the hyphae of some predatory molds are transformed into rings or nets, which are used to catch other small organisms, such as nematodes and paramecium.
Sclerotium: dense tissue formed by a large number of hyphae, which is dormant and can resist adverse environmental conditions. Its outer layer is hard and dark; The inner layer is loose and mostly white. For example, medicinal poria cocos and ergot are sclerotia.
Fruit body: specialized by a large number of aerial hyphae. Fruit body refers to any structure with a certain shape that can produce spores in or on it. For example, there are three kinds of complex fruiting bodies that can produce sexual spores, which are called ascomycetes, ascomycetes and ascomycetes.
Because the mycelium of mold is thick and long, the colony of mold is large. The hyphal spread of some molds is unrestricted, and their colonies can extend to the whole Petri dish, while others have certain limitations, with the diameter below 1 ~ 2 cm. Generally, the colony texture is looser than actinomycetes, and its appearance is dry and opaque, showing a dense or loose spider web, fluff or cotton wool; Colonies are closely related to the culture medium and are not easy to pick. The colors of the front and back of colonies and the colors of the edges and centers are often inconsistent.
type
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Mold has strong reproductive ability and various reproductive methods. Although any segment of fungal mycelium can develop into a new individual under suitable conditions, in nature, fungi mainly reproduce by producing various asexual or sexual spores. Spores are a bit like seeds of plants, but they are extremely numerous and small in size.
The asexual spores of mold are directly formed by the differentiation of reproductive hyphae, and the common ones are arthrospores, chlamydospores, sporangium spores and conidia.
Sporangium spore: Spore born in sporangium, which is a kind of endospore. Fungi without hyphae (such as Mucor and Rhizopus) mainly form sporangium spores.
Conidia is an ectospore, which is specialized from the top of mycelium or the stalk of bifidobacteria. Moulds with septate hyphae (such as Penicillium and Aspergillus) mainly form dichotomous spores.
Arthrospore: formed by the rupture of hyphae (such as Geotrichum candidum).
Chlamydomonas: Usually, the middle cell of mycelium becomes larger, the protoplasm is concentrated and the cell wall becomes thicker (such as Mucor racemosa).
The process of sexual reproduction of mold includes three processes: cytoplasmic mating, nuclear mating and meiosis. Common sexual spores are oospores, zygospores, ascospores and basidiospores.
Cytoplasmic matching: refers to the fusion of cytoplasm after two haploid cells or hyphae of different sexes contact and combine.
Nucleation: nuclear fusion produces diploid gametophyte nuclei.
Meiosis: After meiosis, the number of chromosomes in the nucleus reverts from diploid to haploid.
Synspore: two gametophytes combine and develop into zygospores after mass matching and nuclear matching. The formation of zygospores can be divided into two types: (1) heterothallism, which consists of hyphae of two different strains; (2) Homologous mating: it can be formed by combining the same mycelium. When the zygospore germinates, the cell wall breaks, and a bud tube grows, and a sporangium is formed on the bud tube. The meiosis of zygospores occurs before or during germination.
Ascomycetes: Two kinds of cells of different sexes are combined on the same mycelium or two adjacent hyphae to form Ascomycetes. Ascomycetes are formed by plasmolysis, nuclear pairing and meiosis, and there are 2~8 cysts. Many ascomycetes gathered together are wrapped by surrounding hyphae into ascomycetes, and there are three types of ascomycetes: 1) completely closed, called closed ascomycetes; 2) There is a hole in the middle called capsule shell; 3) The disc is called apothecium.
Oospore: It is formed by combining two gametophytes with different sizes. The small gametophyte is called sperm organ, and the large gametophyte is called egg storage organ. When combining, the protoplasm and nucleus in the sperm cell enter the egg storage device and cooperate with the egg ball in the egg storage device, and then the egg ball gives birth to the outer wall and develops into oospores.
The spores of mold are small, light, dry and abundant, with different shapes and colors, long dormancy period and strong resistance. Each individual often produces tens of thousands of spores, sometimes reaching tens of billions, hundreds of billions or even more. These characteristics help mold to spread and multiply everywhere in nature. For human practice, these characteristics of spores are beneficial to inoculation, expanded culture, strain breeding, preservation and identification, but its disadvantage is that it is easy to cause pollution and spread mold and mycosis to animals and plants.
First, the mycelium does not separate molds: sporangium spores, thick film spores.
2. filamentous fungi; Conidia and schizospores.
Third, mold propagation: 1, asexual propagation: sporangium spores.
Conidia;
Schizospore;
Thick-film spore;
2. Sexual reproduction: zygospores.
Ascomycetes (2-8)
mould proof
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Mold is everywhere in our life. He likes warm and humid environment. When there is a suitable environment, it will multiply. Measures must be taken to stop the propagation of mold or cut off its transmission route to get rid of mold infection:
Human body prevention
1. Pay attention to the growth of mold in a certain part of the body, such as nails. Sometimes mold can invade nails and cause onychomycosis, so don't let nails grow, and wash them often. Sweating has many wrinkles, especially for fat people. If you sweat a lot in summer, mold may grow in the folds. Foot is also conducive to the growth of mold environment, beriberi patients should pay more attention to prevent infection in other parts.
2. Wash underwear separately, especially when family members or themselves have tinea pedis or onychomycosis. In order to prevent cross infection, they should be washed separately.
3. Don't abuse antibiotics. Eating a large amount of antibiotics may inhibit the flora beneficial to human health, destroy the natural defense barrier of human body, and cause a large number of molds to multiply.
4. Be alert to the mold hidden in the washing machine. If the washing machine is used for a long time, it will certainly breed mold. The easiest way is to clean it thoroughly with water of about 60 degrees. At the same time, the washed clothes must be dried in the sun, and the ultraviolet rays in the sun can kill the residual mold.
It is best not to use public or used washing utensils in public places. At the same time, choose the appropriate personal cleaning care products.
6. Correct contraception, estrogen in contraceptives can promote mold invasion. If fungal vaginitis recurs, try not to use drugs for contraception.
7. It is best to choose cotton underwear. Tight-fitting chemical fiber underwear will increase the temperature and humidity of vagina, which is beneficial to the growth of mold.
8. If you have fungal vaginitis, the man should also receive treatment at the same time to avoid cross infection.
9. Wearing cotton underwear. Tight-fitting chemical fiber underwear will increase the temperature and humidity of vagina, which is a "living" environment for molds to clap their hands! Choose cotton underwear!
10. Control blood sugar and clean vulva with alkaline products. Female diabetic vagina has high glycogen content and high acidity, which is easy to be invaded by mold. Therefore, while controlling blood sugar, we should also pay attention to cleaning vulva and choose products with weak pH value.
Food prevention
1. Anti-mildew by indigenous method Adding 1 kg kelp into 100 kg rice can effectively kill pests and inhibit mold. Although there are many ways to prevent mildew, it is limited to eliminate the harm of mycotoxin, so don't be stingy with some moldy food, be sure to throw it away in time, and don't eat it with luck, otherwise it will cause food poisoning.
2. Most mildewproof molds preserved in low oxygen are aerobic microorganisms, which need oxygen for growth and reproduction. Therefore, sterilized bottled (canned) food can be filled with nitrogen or carbon dioxide, added with deoxidizer, tamped with food, degassed or sealed with oil, which can create an anoxic environment and prevent most molds from reproducing. For example:
● Soy sauce: Drop a layer of cooked soybean oil or sesame oil in the bottle filled with soy sauce to isolate soy sauce from the air and prevent mold growth.
● Sausage and meat pickled food: dip a cotton swab in a little vegetable oil or sesame oil and evenly spread it on its surface to prevent mildew.
● Vinegar: Add a little sesame oil or cooked peanut oil to the vinegar bottle to isolate the vinegar from the air and prevent long white film.
● Dry products such as dried fragrant shavings, fungus, dried bamboo shoots and dried shrimps are kept in sealed containers.
3. Food should be kept in a ventilated and dry environment.
4. Low-temperature mildew-proof meat food can remain unchanged for 20 days at the low temperature of 0℃; The rice cake can be completely immersed in a porcelain jar filled with water, and the water temperature can be kept below 10℃, which can prevent mildew.
5. Heating sterilization method For most molds, heating to 80℃ for 20 minutes can kill them; Mold has weak radiation resistance, so it can be killed by radiation from radioisotopes. However, aflatoxin is resistant to high temperature, and pasteurization (80℃) cannot destroy its toxicity. [2]
6. The harvested grain should be dried in time and stored in a ventilated and dry environment. In rural areas, if it is found that there is only a small amount of mildew in stored grain, the following methods can be adopted: (1) manually picking out moldy corn, peanuts and other large particles; Moldy wheat, rice and other small particles can be washed away by rinsing. [3]
Feed prevention
1. Select and cultivate antibacterial feed crop varieties. Different feed crop varieties have different sensitivities to mold, and cultivating antibacterial varieties can greatly reduce the probability of feed crops being infected by mold. This is also the fundamental way to prevent mildew, and the gradual expansion of bio-genetic engineering makes it possible to cultivate disease-resistant varieties.
2. Choose appropriate planting or harvesting techniques. The experimental results show that 80%-90% of Aspergillus flavus isolated from peanuts can produce toxins, which is much higher than that isolated from other crops. Therefore, the pollution rate of Aspergillus flavus is high and the content of Aflatoxin (AF) is also high in the field where peanuts are planted continuously. Broken flowers are easy to pollute Aspergillus flavus and are also conducive to the production of toxins. Therefore, if planting techniques such as crop rotation and appropriate harvesting methods are adopted, the pollution of mold and mycotoxin will be greatly reduced. In addition, insect bite, rat bite, grinding and squeezing should be avoided as much as possible during harvesting, storage and transportation, so as not to damage the epidermis and shell of corn, peanuts and other grains; Broken seeds should be removed, because such seeds are usually highly polluted.
3. Strictly control the moisture content of feed and raw materials. The three main conditions that cause feed mildew are humidity, temperature and oxygen. If we can control one of these three conditions, we can effectively prevent mildew. Generally speaking, it is the easiest way to control the moisture below the safety line, so the crops should be dried quickly and evenly after harvest. The water content of rice should be controlled below 65438 03%, corn below 265438 0.5% and peanut below 8%.
4. Improve storage conditions and inhibit mold growth. The mildew of feed mostly occurs during storage, so the mildew prevention during storage is an important part of the mildew prevention of feed.
4. 1 Physical mildew prevention methods: mainly including controlling the storage environment temperature, sealed oxygen storage, modified atmosphere storage, low temperature ventilation storage and radiation method. According to reports, the threshed wet corn is put into a sack lined with plastic bags, and the mouth of the bag is filled as much as possible. Since then, the oxygen in the bag is consumed because of the respiration of corn itself, not only Aspergillus flavus is difficult to grow, but also other molds can be inhibited. This is an economical, simple and promising anti-mildew method. Low temperature ventilation storage method is widely used in China, which combines low temperature with mechanical ventilation to make feed reach safe moisture content. It is not only suitable for pellet feed, but also has obvious application effect on powder with high moisture content. With the development of radiation food technology, many countries have also carried out the research and application of feed radiation treatment. ?
4.2 Chemical mildewproof method adding mildewproof agent: This method is more suitable for feed industry. As a feed mildew inhibitor, it should not only inhibit mold, but also be harmless to people and animals, with low price and convenient and reliable use. Propionic acid and its salts, sorbic acid and its salts, sodium diacetate, ethoxyquin, fumaric acid, cysteamine acetate, gentian violet and dimethyl fumarate are commonly used as mildewproof agents. Propionic acid and its salts, followed by sorbic acid and its salt acetic acid, are the most used fungicides in feed industry in the world. Beneficial therapy: the main function of beneficial acetate is to inhibit the biosynthesis of AF. 9%- 15% aqueous solution was prepared with ethephon acid, and the fresh flower consumption was 3? 5% liquid weight, fully stirred and mixed with peanuts, stored in a polyethylene bag with a relative humidity of 100% at 28-30 degrees Celsius, and no AF biosynthesis was found within 90 days.
4.3 Microbial inhibition method: Japan Yongsen Food Company found 7 kinds of microorganisms that can devour Aspergillus flavus and inhibit AF production, but no practical report was found.
4.4 Comprehensive method: Enzymes and antioxidants, as fungicides, are new and efficient fungicides in the world in recent years. Its principle of action is different from that of chemical fungicides. It replaces the enzyme system in the mold by adding enzymes, and prevents the mold from absorbing oxygen normally with antioxidants, thus preventing the normal physiological function of the mold to achieve the effect of mildew prevention. The enzyme used is 1-500 times stronger than that in mold. When it acts on mold, the enzymes in mold will be destroyed and denatured, so that mold can not absorb nutrients from feed. Coupled with the role of antioxidants, mold can not get enough oxygen, thus inhibiting its growth. This mildew inhibitor will not produce resistance to mold, and it is safe and reliable to use, and has no adverse effects on the outside world.
Mold test is to test whether the mildew-proof ability of products and equipment are adversely affected by mold under conditions conducive to mold growth (that is, high humidity and warm environment and the presence of inorganic salts).
The standards for mold testing mainly include:
GJB150.10-1986 Environmental test method for military equipment: mold test.
Hb 6167.11-1989 environmental conditions and test methods of airborne equipment for civil aircraft mold test.
GJB4. 10 Marine Electronic Equipment Environmental Test Mold Test
GB T 2423. 16- 1999 environmental testing of electrical and electronic products-part 2 test methods, test j and guidelines for molds.
GB/t 10588-2002 GB 10588-89
There are few laboratories that can carry out mold tests, and only the environmental reliability and electromagnetic compatibility test center and an air force research institute are known.
Environmental effect
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First, in view of the places and reasons that are easy to produce mold in the external environment.
1. The walls of the production workshop are wet, and mold is easy to grow in the wet parts.
2. The pipes and walls with condensed water in the workshop are easy to breed mold, and the rupture of water pipes can also lead to mold production.
There is always a certain amount of water vapor in the air, but in most cases we can't see it. But when the water vapor is liquefied, such as when we take a bath or take a bath, the mirror surface in the bathroom will get wet, and then we can see them. Hot air contains a lot of water. When hot air cools, water condenses and liquefies. Condensation and liquefaction usually occur in the lowest temperature part of the house, such as the low temperature part on the wall. It is in these low temperature parts that mold is most likely to be produced.
4. Normal ventilation cannot be guaranteed in the workshop, and it is impossible for the workshop to easily breed mold under the specified humidity.
5. Where the workshop is hot and cold, it is easy to produce condensed water, which is easy to be destroyed by mold.
6. Equipment against the wall is prone to condensate and mildew.
7. Please close the door of the workshop with relatively low temperature. If the doors of these low-temperature workshops are not properly closed, the hot air from the workshop next door will flood in, resulting in high humidity, air cooling will liquefy, and mold will easily breed.
8. Ensure the normal operation of the air conditioner and ensure that the air in the workshop can meet the required indicators. The ventilation degree of air conditioner directly affects the production of mold. If the workshop can ensure that the air containing a lot of water is discharged from the workshop in time, the possibility of mildew may be greatly reduced.
Second, once the mold enters the food,
There are many factors that affect the growth, reproduction and toxin production of mold, and there are also many conditions closely related to food, such as moisture, temperature, substrate, ventilation and so on. Therefore, controlling these conditions can have a great influence on the distribution of molds and toxins in food.
1. moisture
One of the main conditions for mold growth and reproduction is to keep a certain amount of water. Generally speaking, the water content of rice and wheat is below 14%, soybean is below 1 1%, and dried vegetables and fruits are below 30%, so it is difficult for microorganisms to grow. The part of water in food that can really be used by microorganisms is also called water activity (Aw). The closer Aw is to 1, the easier it is for microorganisms to grow and reproduce. When the water activity in food is 0.98. Microorganisms are the easiest to grow and reproduce. When Aw is lower than 0.93, microbial reproduction is inhibited, but mold can still grow. When Aw is lower than 0.7, the reproduction of mold is inhibited, which can prevent the reproduction of toxic mold.
2. Temperature
Temperature has an important influence on the reproduction and toxin production of mold. The optimum temperature of different kinds of molds is different. The optimum temperature for the propagation of most molds is 25 ~ 30℃, which is lower than 0℃ or higher than 30℃ and will not produce toxins or weaken their toxin production. For example, the lowest breeding temperature range of Aspergillus flavus is 6-8℃, the highest breeding temperature is 44-46℃, and the optimum growth temperature is about 37℃. But the toxic temperature is different, slightly lower than the optimal growth temperature. For example, the optimum toxic temperature of Aspergillus flavus is 28-32℃.
3. Food substrate
Just like the growth and reproduction conditions of other microorganisms, the growth of mold in different food substrates is different. Generally speaking, the possibility of mold growth in nutritious foods is greater, and natural substrates produce toxins better than artificial media. The experiment confirmed that under the same culture conditions, the aflatoxin yield of the same mold strain based on sugar-rich wheat and rice was higher than that based on oil. In addition, mold with slow ventilation and quick air drying is easy to breed and produce poisons.
4. Mold species
There are differences in the growth and reproduction speed and toxin-producing ability of different kinds of molds. Among mycotoxins, aflatoxin, ochratoxin, yellow-green penicillin, red penicillin and penicillic acid are the most toxic. Five toxins are known to cause cancer in animals. They are Aspergillus toxin (b? 1、G？ 1、M？ 1), Huang Tianjing, cyclosporine, patulin and cold medicine.
Treat mold
Mold can cause allergic rhinitis, which is hidden in damp places, such as bathrooms, toilets, cabinets and pools. A large number of molds can cause bronchial asthma. In order to avoid mildew at home, we should do the following:
Activated carbon is often used to keep the house dry.
Empty the pots and pans at home to prevent mildew.
Closed spaces such as toilets and bathrooms should be ventilated frequently.
Check faucets and water pipes to prevent water leakage.
Mould harm
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The toxicity of mycotoxin to human beings and livestock and poultry is mainly manifested in nervous and endocrine disorders, immunosuppression, carcinogenesis and teratogenesis, liver and kidney damage, reproductive disorders and so on. Chickens are naturally sensitive to mycotoxin, and low toxin content in feed will lead to a large number of chickens' deaths. The effects of mycotoxin on laying hens are concentrated in the following aspects: ovary and fallopian tube atrophy, egg production decline and abnormal egg production; The feed intake decreases, the production performance decreases, and the feed reward decreases; The hatching rate of eggs decreases. Different mycotoxins do different harm to laying hens. Among the known mycotoxins, ergot toxin, hyphomycetin, pythium toxin, zearalenone, aflatoxin and ochratoxin have great influence and toxic effects on laying hens.
1 ergotoxin
Ergot toxin is secreted by ergot fungi in grains, and its chemical essence is a chemical group composed of various alkaloids in sclerotia. In these chemical groups, some alkaloids invade the nervous system, causing spasms and sensory nerve disorders; Some invade the vascular system, causing vasoconstriction and gangrene of limbs; Some invade the endocrine system and affect the regulation of nerve division and secretion in the anterior pituitary gland. Therefore, ergot poisoning is characterized by vascular, nervous and endocrine disorders, while ergot poisoning in laying hens is characterized by reduced feed intake, decreased egg production rate and sparse fecal excretion.
Trichosporon toxin
A variety of fungi, including Fusarium, can produce all kinds of hyphotoxin. Studies have shown that about half of the more than 100 kinds of mitomycin toxins found are produced by Fusarium. The mechanism of action is to destroy structural lipids and inhibit protein synthesis and DNA synthesis. Within a few days after laying hens ate the feed contaminated by this toxin, the egg production decreased rapidly, the eggshell became thinner, and the oral mucosa of sick chickens festered, forming a yellow scab. Autopsy showed that the liver was brown and fragile, the kidney was swollen, urate was deposited in the fallopian tube, local ulcer was found in the crop, and the muscular stomach wall was thickened.
3 Rot horse toxin
Secreted by Fusarium moniliforme, the poisoning mechanism is to destroy the synthesis of sphingolipids. The poisoning symptoms of laying hens are diarrhea, black and sticky feces, weight loss, limb disability and increased mortality. In vitro experiments show that human toxin has toxic effects on macrophages and lymphocytes, reducing the bactericidal activity of immune cells.
4 Zearalenone
Zearalenone is mainly produced by Fusarium graminearum, and many Fusarium species such as Fusarium pink and Fusarium tricuspidata can also produce this toxin. Zearalenone is a substituted 2,4-dihydroxy benzoic acid lactone with seven derivatives including zearalanol. It is a phytoestrogen, which is very toxic to chickens. The clinical manifestations of layer poisoning are cockscomb enlargement, ovarian atrophy, decreased egg production rate and ascites in some cases.
aflatoxin
Aflatoxin is a highly toxic carcinogen, which is produced by Aspergillus flavus, Aspergillus parasiticus and Penicillium papaya. Aflatoxin is a compound composed of two unequal dihydronitrofurantoin rings. It binds to nuclear and mitochondrial DNA, resulting in impaired protein synthesis, interfering with liver and kidney functions and inhibiting the immune system. The clinical manifestations of laying hens are loss of appetite, decreased laying rate and increased mortality. Autopsy showed that liver and kidney were swollen and pale, subcutaneous hemorrhage, pericardial effusion, gallbladder dilatation and catarrhal enteritis; Microscopic examination showed fatty degeneration of liver and bile duct hyperplasia.
6 ochratoxin
Ochratoxin is a nephrotoxin produced by Ochratoxin and pure Penicillium, and it is the most toxic mycotoxin to poultry. Ochratoxin poisoning can cause primary nephropathy, and also affect the liver, immune organs and hematopoietic function. Autopsy showed that the liver, pancreas and kidney were pale, the kidney was swollen, and white urate was deposited in the ureter. The feed contaminated by ochratoxin has poor palatability, and laying hens will lose weight due to anorexia, and the yield and quality of eggs will decrease. For breeding eggs, ochratoxin poisoning will lead to the increase of abnormal embryos.
Prevention and control countermeasures
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1 Strengthen feed production management
First of all, we must strictly control the procurement of raw materials to prevent moldy raw materials from being put into storage; Control the temperature and humidity of the warehouse, pay attention to ventilation, and do a good job in cleaning the corners of the warehouse to prevent raw materials from deteriorating during storage; Control feed processing, preparation, transportation and other links, control the storage environment of feed, shorten the storage time as much as possible, and prevent feed from going moldy and deteriorating in poultry houses.
2 rational use of feed fungicides
Feed mildew inhibitor should have the characteristics of inhibiting the growth of mold, but it is not toxic to animals. Therefore, as a feed mildew inhibitor, it must meet the following three principles: first, it has a strong broad-spectrum antibacterial effect; Second, the pH value is low, which can be released in low moisture feed; Third, it is convenient to operate, safe and economical to use, and has no carcinogenic, teratogenic and mutagenic effects. Effective addition will not affect animal health and palatability of feed. Commonly used fungicides mainly include the following three categories: the first category is organic acids, such as propionic acid, sorbic acid, benzoic acid, acetic acid, dehydroacetic acid and fumaric acid; The second category is organic acid salts and their esters, such as propionate, sodium (potassium) sorbate, sodium benzoate and dimethyl fumarate. The third category is compound mildew inhibitor. Organic acids have good mildew-proof effect, but they are corrosive; The anti-mildew effect of organic acid salt is worse than that of organic acid, and it must be carried out under certain moisture and pH value, but it is less corrosive. The compound mildew inhibitor has strong mildew-proof effect and low corrosiveness.
3 Treatment of poisoned laying hens
Changing feed is undoubtedly the most effective way to solve mold poisoning. After providing pollution-free feed and using a certain amount of mycotoxin or nystatin, most poultry poisoned by mycotoxin will recover quickly. In addition, vitamin supplementation, such as vitamin E and vitamin C, can partially inhibit the toxicity of T-2 toxin and ochratoxin to laying hens. N- acetylcysteine and thiamine can reduce the toxicity of aflatoxin, and its mechanism is to increase the synthesis of glutathione.
urocystitis
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cause
The incidence of fungal cystitis is relatively high. Female patients are usually infected upward, while male patients are usually secondary to diseases such as prostatitis, prostatic hyperplasia, calculus and upper urinary tract infection.
treat cordially
1. Symptomatic symptoms, such as antispasmodic drugs, anti-infection treatment, alkaline urine with sodium bicarbonate, hot compress in bladder area, hot water sitz bath, etc.
2. Etiology, mainly to find out the cause, and then actively treat the primary disease, such as relieving obstruction and correcting deformity.
3. General treatment methods, such as taking more rest, drinking more water and strengthening nutrition.
kysthitis
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pathology
Anatomically speaking, women's vulva is in a natural closed state, ensuring that the vagina is not connected with the outside world. Usually, the vaginal wall is also closed, and the cervix is also closed.
In addition, indirect contact infection is also a route of transmission of fungal vaginitis. What items may be infected with vaginitis?
Contact with toilets, bathtubs, bath chairs and towels in toilets infected by mold patients, and the use of unclean toilet paper can all cause transmission. Fungal vulvovaginitis can occur when the number of candida in infected vulva and vagina reaches a certain level.
Other behavioral antibiotics and anti-inflammatory drugs that can cause vaginitis are the culprit.
Taking a lot of antibiotics can also lead to vaginitis. As long as antibiotics are used, whether oral or injection, it will inhibit the lactic acid bacteria in the vagina from disturbing the natural ecological balance of the vagina and changing the microenvironment of the vagina, and the pathogenic bacterial pathogens may multiply in large numbers, eventually leading to local candidal vaginitis. So generally don't take a lot of antibiotics.
Frequent washing can lead to diseases.
In order to maintain hygiene, some women often use drug lotion to clean the vagina, which is easy to destroy the acid-base environment of the vagina, but easy to be infected with candida vaginitis. In addition, diabetes and pregnancy may lead to a large number of vaginal candida, increasing the carrier rate.
Excerpt from Baidu Encyclopedia