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High GC contents in Gram positive bacteria

Gram positive bacteria containing CG
* Gram positive
* Gender bacillus
* Gender clostridium
* Clostridium tetani
* Clostridium difficile
* Clostridium perfringens
* Gender heliobacterium
Gram-positive bacteria containing CG
GC content
GC = guanine Cytokine
AT = Adenine Thymine
GC content is a feature of the genome of an organism, ie a piece of DNA or RNA, represents the amount of guanine and cytosine pairs, is usually expressed as a percentage, the remaining fraction containing adenine and thymine bases of GC content is sometimes used to classify organisms in taxonomy.
For example, the Actinobacteria are characterized by high GC bacteria, like the Streptomyces coelicolor with 72% GC.
Because nature genetic code is impossible an organism genome containing GC or AT who approaches 0% or 100%.
A species with an extremely low GC is Plasmodium falciparum with a ~ 20% GC, and in these cases is often commonly referred to as high adenine-thymine-guanine instead of Cytokine low.
In particular, genes with GC exons are high, while the introns are generally AT high.
A higher GC implies a higher denaturation temperature.
The GC can be measured by various methods, one of the simplest, the denaturation temperature of the double helix of DNA with a spectrophotometer. DNA response is abrupt when the double helix separates into two strands both when heated sufficiently.
Gram positive
Includes a wide range of bacteria, grouped by their morphological and staining. Typically, within this group are capable of spore bacteria:
These are able to survive in hostile environments by forming a highly resistant structure, the endospore, the life structure more resistant to physical and chemical agents, and therefore, sterilization and disinfection.
While in Gram-positive bacilli are some of the most aggressive pathogens to humans, the vast majority of bacterial species in this group are primary pathogens. Many are part of the normal flora of the human body including skin, gastrointestinal tract, oral cavity and are widely distributed in the environment.
According to their behavior to oxygen are divided into:
a) aerobes: Bacillus.
b) anaerobes: Clostridium
Genus Bacillus
This genus includes the type of aerobic species. Mobile usually peritrichous flagella. Some produce antibiotics which seems to be related to sporulation. Its main habitat is the soil, but are also widespread in the waters, marine sediments, food, pharmaceuticals. Many produce extracellular enzymes and hydrolase.
Chemoheterotrophs are able to breathe using simple organic compounds such as sugars, amino acids and organic acids, in some cases producing ferment carbohydrates and butanediol glycero
A few species, such as Bacillus megaterium, require non-organic growth factors, others may require amino acids, vitamins B, or both. Most are mesophiles, with optimum temperature between 30 and 45 degrees, but some are thermophilic with optimal as high as 65 degrees. Others are true psicotrofilos, able to grow and sporulate at 0 degrees. Are increasingly on a range of pH from 2 to 11.SCIENTIFIC CLASSIFICATION
Since many species endospores can effectively degrade a number of biopolymers (proteins, starch, pectin, etc), is supposed to play a significant role in the biological cycles of carbon and nitrogen.
Can play a role in biodegraded as contaminated and, therefore, can be agents of decay and decline unwanted. Several species of Bacillus are especially important organizations such as the deterioration of food.
They are nitrogen fixers, denitrifying, insect and animal pathogens, thermophiles, producers of antibiotics
In Bergey’s Manual of Systematic Bacteriology (2 nd ed. 2004), phylogenetic classification systems, some Bacillus reassigned as follows:
Reallocations in the genus Bacillus (1986-2004).
* 1. Acidophil: Acyclobacillus acidocalderius, Bacillus coagulans, and Paenibacillus polymyxa.
* 2. Alkaliphiles: B. alcalophilus and Sporosarcina pasteurii. The optimum pH is 8, and some strains grow at pH 11.
* 3. Halophiles: Virgibacillus pantothenticus, Sporosarcina pasteurii. Some strains grow at 10% NaCl.
* 4. Psychrophiles or psychrotrophs: Sporosarcina globisporus, Bacillus insolitus, Marinibacillus marinus, Paenibacillus macquariensis, Bacillus megaterium, Paenibacillus polymyxa. Two species that grow and form spores at 0 ^0 C.
* 5. Thermophile: Acyclobacillus acidocalderius, Bacillus schlegelii, and Geobacillus stearothermophilus. Acidophil and Lithoautotrophs found on this group also. El limit temperature is 65 o C.
* 6. Denitrifiers: Azotoformans Bacillus, Bacillus cereus, Brevibacillus laterosporus, Bacillus licheniformis, Sporosarcina pasteurii, Geobacillus stearothermophilus. More than half reduce NO 3 to NO 2. A process carried out by certain species of Bacillus, is dissimilatory reduction of nitrate, NO 3 is reduced to ammonia (NH 3), but this is not considered denitrification.
* 7. Fixing nitrogen: Paenibacillus macerans and Paenibacillus polymyxa. Paenibacillus macerans is a rather prominent bacteria in soil and decaying plant material. The bacteria fix nitrogen only under anaerobic conditions because they lack a mechanism for protecting their nitrogenase from the harmful effects of O 2.
* 8. The producers of antibiotics, the antibiotics produced by the aerobic sporeformers often but not always. Antibiotics are produced by Brevibacillus brevis gramicidin generated, tyrothricin, Bacillus cereus produces cerexin, zwittermicin, Bacillus circulans, circulina; Brevibacillus laterosporus, laterosporin, Bacillus licheniformis, bacitracin, Paenibacillus polymyxa, polymyxin and colistin, Bacillus pumilus, pumulin, and Bacillus subtilis , polymyxin, difficidin, subtiline and mycobacillin.
* 9. Pathogens of Insects: Paenibacillus larvae, Paenibacillus popilliae and Paenibacillus lentimorbus are invading pathogens. Bacillus thuringiensis parasporal crystal form that is toxic to Lepidoptera.
* 10. Animal pathogens: Bacillus anthracis and B. cereus is the predominant pathogens of medical importance. Paenibacillus alvei, B. megaterium, B. coagulans, Brevibacillus laterosporus, B. subtilis, B. sphaericus, B. circulans, Brevibacillus brevis, B. licheniformis, p. macerans, B. and B. pumilus thuringiensis have been isolated instances of human infections.
Bacillus anthracis:
Are square-ended bacilli of 3-5 microns long and 1-1.2 microns wide, singly or in pairs. It imnovil. The vegetative cell is comparable with other non-spore bacteria, but due to their ability to sporulate, is extremely durable. The spores remain viable for years in the environment. Can be destroyed if subjected to sterilization, being the most resistant living structure. On this basis spores of Bacillus species other than B. anthracis, are used as biological controls of sterilization.
Antigenic structure
Have three major antigens:
* 1. Polypeptide of high molecular weight capsular consists almost exclusively of Dglutamico acid. This is the only medically important bacterial species that possess capsule instead of polysaccharide peptide. There is a single antigenic determinant. For reasons not well known anticapsula antibodies are not protective. The genes that encode this structure is found in a large plasmid.
* 2. Somatic antigen polysaccharide, is a component of the cell wall. The antibodies are not protective. Cross-reacts with blood type A and type 14 Streptococcus pneumoniae.
* 3. Toxins: edema factor and lethal toxin.
The main attributes of virulence of the strains that cause disease are encoded on two plasmids are toxins and capsule.
AB model produces two toxins, which have identical subunit B.
* 1. The B subunit is known as protective antigen. The portion of the toxin that binds to the target site and allows entry into the cell.
* 2. The edema or toxin subunit is enzymatically active component, called edema factor. Adenylate cyclase is a calmodulin-dependent. Is responsible for significant edema at sites of infection, the inhibition of neutrophil function and hinders the production of tumor necrosis factor and interleukin by monocytes. His portion A, called lethal factor is a metalloprotease that inhibits intracellular signaling transduction. Stimulates the release of tumor necrosis factor and interleukin from macrophages, this mechanism seems to contribute to death from sepsis.
Like other bacteria, the capsule is an important virulence factor by inhibiting phagocytosis.
Anthrax and Anthrax is a disease that primarily affects grazing animals, particularly sheep and cattle. The man acquires by accident: in the agricultural context as a local skin infection in the industrial context, the manipulators of leather and animal hair as the acquired pneumonia. It is then, a zoonotic disease and illness. Not all strains of B. anthracis are capable of producing anthrax. Cutaneous anthrax is caused by skin contact with infected material. The spores enter through a skin lesion. When ingested by macrophages at the site of entry, the spores germinate and the cells divide to produce capsule and toxins. Inhalation anthrax occurs when spores enter the air and are deposited in the alveolar spaces, where they are ingested by alveolar macrophages. Within the same germinate and produce toxins, to be then transported by the lymphatic circulation to mediastinal lymph nodes. Reach the bloodstream and can cause septic shock. Germination may occur up to 60 days after the entry of spores into the airway, hence the importance of antibiotic prophylaxis in cases of prolonged exposure for 60 days. It is estimated that inhalation lethal dose for humans is 2500 to 55000 spores.
Veterinary infection has a high mortality rate of sepsis. In humans is a rare disease now. Depending on the route of transmission, produces two main types of infections: a relatively mild skin and respiratory compromises the patient’s life. The skin infection is caused by direct contact with infected animals. Respiratory infection requires the inhalation, which, to be effective, requires bacterial spores are aerosolized. For this reason, this approach rarely occurs naturally and raises the suspicion of intent or bioterrorism, although cases have been associated with inhalation Anthrax large-scale processing of animal hair and wool contaminated conducted in small, enclosed spaces. Exceptionally gastrointestinal form occurs by ingestion of bacterial spores, from contaminated meat. It is not transmitted from person to person. Skin infection, comprising 95% of human cases, is manifested by a painless papule blue black center with a large edematous edge. Without treatment has a 20% mortality. Pulmonary infection is a severe respiratory infection that progresses to acute respiratory failure and has a very high mortality rate (100% without treatment).
Is sensitive to penicillin, erythromycin, tetracycline, gentamicin, chloramphenicol and quinolones.
The control of human anthrax depends mainly on the control of animal anthrax. Thus, measures should be taken as the livestock vaccination and proper handling of dead cattle, clothing and work materials, etc. It has developed vaccine subunits B, obtained by filtration. A veterinarian level using a more effective vaccine, made from live spores of strain is not capped.
Is a Gram-positive, strictly aerobic, morphologically related to Bacillus cereus and Bacillus anthracis.
These three bacterial species during their life cycle, have two main phases
* 1. The vegetative growth phase where the bacteria double every 30-90 min by bipartition depending on culture medium and
* 2. Sporulation phase, which is a program of differentiation to spore bacteria, is triggered when the bacteria are found in nutrient limitation.
This is considered a ubiquitous bacterium that has been isolated and all over the world and from many different systems such as soil, water, plant leaves, dead insects, cobwebs, etc.
This bacillus has a body known as parasporal crystal, which is protein in nature and has insecticidal properties, consists of endotoxins also known as Cry and Cyt proteins. Active endotoxins found contrainsectos as butterflies, beetles, mosquitoes, ants, mites and also other invertebrates such as worms.
Little is known about the natural habitat of Bacillus thuringiensis yet given their vitamin requirement, and some amino acids such as glutamic acid, as well as their biopesticide activity, it is thought that the vegetative life form occurs only within infected insects until sporulates and is released into the environment where it remains in the form of spores, which explains their wide distribution.
In addition to endotoxin, B. thuringiensis has developed a number of virulence factors that allow it to infect their targets with greater efficiency. Among these virulence factors are:
* 1. Phospholipases,
* 2. Proteases,
* 3. Chitinase
* 4. Labile exotoxins.
It is proposed that these factors help bacteria in the infection of the insect. It is reported that in some cases the mixture spore / crystal kills far more efficient than single crystals.
As mentioned, there are two types of endotoxins, Cry proteins and Cyt proteins. The symptoms seen from the susceptible insect larvae ingest the crystals and Bt spores are: cessation of intake, bowel paralysis, vomiting, diarrhea, paralysis and finally death. The mechanism of action of Cry proteins is a multistep process: solubilization of the crystal, protoxins processing, receptor binding, membrane insertion, aggregation, pore formation and cytolysis.
Most of the Cry proteins are produced as protoxins, which to be active must be processed by proteases of the midgut of insects by releasing the toxic fragment.
It has been estimated that 2% of global pesticide market is satisfied with biopesticides, which dominates Bt 95% of sales. There have been several factors have enabled their success in agriculture. The most important is its high specificity to the target insect and its safety to mammals, other vertebrates, including plants and other beneficial insects. Bt toxins have been used as bio-insecticides in agriculture during the past 40 years, mainly in vegetable crops and cereals. Residence times of the Cry proteins in the environment are very short, so the selection ress is very low. In this sense, Bt has been used as an alternative compatible with the environment for agricultural pest management. Paradoxically, the benefits of Bt become important disadvantages for commercial use. The narrow host range causes toxins are not available for each pest that affects human activity. The reduced time spent in the environment requires a deep understanding of the biology and behavior of the pest to be controlled and that a toxin may be active larval stages, but no decrease or even be toxic for adults.
Another limitation was the utlizacion of Bt for control of sucking and boring insects and the application of Bt products has traditionally been sprayed products and dietary habits of these insects prevents the ingestion of Cry toxin. This problem has been solved with the creation of transgenic plants that produce Cry toxin systemically making it accessible to insect borers. Finally, there is a risk for development of resistance by the increased use of Bt as a spray of crystals and especially in transgenic plants that constitutively express one or several Cry toxins.
The aim is that the plant, once transformed with the toxin gene, express it enough to kill susceptible to pests that consume them. Since 1987, the first reports appeared on snuff and tomato plants that showed sufficient expression of Bt toxin to confer high levels of resistance.
Causes two types of food poisoning. One type is characterized by nausea, vomiting and abdominal cramps and has an incubation period of 1 to 6 hours. The second type is manifested primarily by abdominal cramps and diarrhea with an incubation period of 8 to 16 hours. The diarrhea may be a small volume or profuse and watery. This type is known as the long incubation or form of the disease, and that is most similar to food poisoning caused by Clostridium perfringens. In either type, the illness usually lasts less than 24 hours after onset.
The short incubation of the disease is caused by a preformed heat-stable enterotoxin. The site and mechanism of action of this toxin is unknown. The long incubation of the disease is mediated by a heat-labile enterotoxin, which apparently activates intestinal adenylate cyclase and causes intestinal fluid secretion.
According to researchers discovered a group of Ohio University who is studying in an area of China where there are gold mines, in places where the metal abundance is also an abundance of spores of Bacillus cereus. This bacteria is not damaged by the presence of gold. The secret of this immunity is in the spores, so look for these spores is an effective method for gold and more economical than the methods used by mining companies.
BACULLUS sphaericus:
It has been studied for its ability to produce a toxin active against mosquito larvae. Mosquitoes ingest the bacteria and the toxin disrupts the gut of the mosquito, causes no damage to mammals. This organism is used as a biological insecticide and is effective from one to four weeks after application.
Is an organism that is found throughout the world.
It is used as a pattern of biological macromolecules such as enzymes, receptor proteins or nucleic acid and thermal stabilization of lipid-based structures such as the membrane.
Bacillus stearothermophilus:
Growing at 65 ^0 C and has torerancia acid. It occurs in soil, hot springs, desert sand, the Arctic waters, ocean sediments, food and compost.
Temperature limits for growth is 45 o and 65 o C. The pH range for growth of around 2. Found in hot acid environments. Spore heat resistance are surprisingly weak.
Tolerant of alkaline conditions and does not grow at pH 7. Able to grow at pH> 10.
Paenibacillus ALVELI:
Are isolated from soil and honeybee larvae suffering from the disease European foulbrood. Not classified as a pathogen of insects.
Bacillus badius:
Has been isolated from the feces, dust, marine sources, food and antacids.
Brevibacillus brevis:
Has been isolated primarily from soil and food. Requires a mixture of amino acids without vitamins for growth.
Bacillus circulans:
Some strains are cellulolytic.
Bacillus firmus:
Isolated from the soil. Pigmented strains occur in salt marshes.
BACILLUS Insolitus:
Sporulation occur at 0 degrees. In the Arctic is in the soil.
Brevibacillus laterosporus:
Produce a canoe, as a body attached to a lateral position in the sporangium. Rarely isolated, but has been found in dead bee larvae, soil, water and antacids.
Paenibacillus lentimorbus:
Nutritionally most annoying and widespread, infects the Japanese beetle. Isolated from diseased larvae or infected combs.
Bacillus lentus:
Nutritionally more versatile, isolated from soil, food and spices.
Bacillus licheniformis:
The enzymes produced by these bacteria are widely used as additives in detergents.
Produces poly-D-glutamate. Red pigment produced by many strains. Spores are produced on the ground. Source of industrial bacitracin, an antibiotic useful. Found in the feathers of birds that live on earth as aquatic species such as sparrows and ducks. Is implicated in gastroenteritis, peritonitis and food poisoning and toxemia and abortions in cattle. It is a common contaminant in dairy products. Optimum temperature for growth at 5 ^0 ^0 C. Currently investigating the ability to degrade feathers for agricultural purposes.
Paenibacillus macerans:
Pathogen in bees, which causes “AFB.”
Fix nitrogen in anaerobic conditions. Degrades the pectin and plant polysaccharides. Some moderately thermophilic strains. It has also been found in fruit canned at pH 3.8.
Bacillus megaterium:
It has the largest cell diameter any spores ranges from 1.2 to 1.5 micrometers. The spores are common in soil. Living in desert environments. Used as a soil inoculant in agriculture and horticulture.
Not a human pathogen, although they can contaminate food, but rarely causes food poisoning. This organism produces the proteolytic enzyme subtilisin. Can be used as a natural fungicide and biological control agent. It is used to create enzymes amylase.
Degrades the pectin and polysaccharides in plant tissues, and some strains cause rot in potato tubers live. It grows in a minimal defined medium without added growth factors. Endospores are widespread. No food grows in acid under aerobic conditions.
Bacillus coagulans:
Includes acidophilic strains. The spores are relatively scarce in the soil. Can multiply in acidic foods like canned tomato juice. Found in antacids and medicated creams. Its main use is as a probiotic in pigs and shrimp. There are some references to the use of this bacterium in the improvement of the vaginal flora. This organism can germinate and proliferate in the intestine. It can grow in a pH of 4.2.
Gender Sporosarcina
This genus is unique among esporoformadores are strict aerobes, round or oval.
This genus has two species:
S. urea and S. halophila: species urea breaks down urea, dramatically raises the pH of the medium. S. Urea is commonly found in soil and recent studies suggest that soils receiving inputs of urine, such as soils in which the animals are usually wet, are enriched with the organism.
Sporosarcina UREA:
Coccus spore-forming bacteria. This soil bacteria produces the enzyme urease, which breaks down urea to provide the body with a nitrogen source. Therefore, it is believed to play an important role in the decomposition of urea in the soil.
They are saprophytic, with the exception of C peritrichous Perfringers.
Bodies are seen alone, in pairs or short chains
Its name derives from the Greek Klostro the form of phosphorus, straight or curved in different sizes.
The spore is round or oval being subterminal.
No cytochrome and mechanisms of phosphorylation is why have a fermentative metabolism saccharolytic species, proteolytic, and glycolytic butterfat because they produce large amounts of proteinases, deoxyribonucleases, lecithinase and neuraminidase.
Clostridia by fermenting sugar yield as final product butyric acid, acetone and butanol. A group ferment cellulose to form acids and alcohols. Another group gets its energy by the fermentation of amino acids as alanine, cysteine, glutamate, glycine, histidine, serine or threonine.
Many of the products of fermentation caused by clostridia are smelly, so that the smell of putrefaction is usually by itself reveal the presence of clostridial fermenters.
Toxins secreted hemolytic necrotizing effect to be potentially lethal.
The toxins can cause invasive infections such as myonecrosis and gas gangrene if introduced into damaged tissue. Approximately 30% of clostridia that effect. An ecological problem, still unanswered is the role these toxins play in natural environments microorganisms.
Not all species are pathogenic, some are part of the normal intestinal flora such as Clostridium sordellii, a resident of the female genital flora, but this increased Clostridium death occurs in women because of toxic shock syndrome after delivery. Clostridium tetani, is an inhabitant of the gastrointestinal tract of humans and animals.
The main habitat is the soil, is commonly found in water, milk, meat and vegetables, living in anoxic, but not everyone has the same sensitivity to oxygen requires the total anaerobic Clostridium tetani, Clostridium perfringens, while less demanding . Generally the oxygen kills them.
The optimum growth temperature between 15 o and 69 o C and grow at a pH between 7 and 7.4, so they are easily inactivated at acid pH or basic, such as stomach acid, cleaners and disinfectants such as chlorine and even at pH organic acid found in lemon juice.
Are chemoorganotroph, produce large amounts of gas, mainly carbon dioxide and hydrogen.
Clostridium Botulinum
Presents subterminal spores, widely distributed in the soil, so that pollute water, long bottom of pools, dust, vegetables, fruits and intestinal contents of mammals, birds.
Foods associated are:
* 1. That was poorly processed or raw.
* 2. What are spores and then kept in temperature and pH conditions that allow the multiplication of bacteria and the development of the toxin.
* 3. Foods that were not heated before consumption.
* 4. Honey is the main source of dietary clostridium botulinum spores associated with infant botulism.
* 5. Any food of animal or vegetable origin.
* 6. Meat and protein foods with low acidity often causes gas and odor.
* 7. It is common in wild birds and poultry.
* 8. Cattle, horses.
* 9. Some species of fish and shellfish.
* 10. Examples: soups, beets, asparagus, olives, spinach, tuna, chicken, chicken liver, foie gras, sausages, ham, sausage, stuffed eggplant, lobster and smoked and salted fish.
* 11. Canned up.
Causative agent of botulism
Its growth is inhibited at a pH lower than 4.5 or high salt concentrations.
Each species of C. secret botulinum toxin type only. The toxin is a protein synthesized crystalline form during cell growth in a very low virulence protoxin, accumulate in the cytoplasm and are released after cell lysis. There are 7 different species of C. botulinum according to their toxin properties:
* 1. Type A is highly virulent, were found in plants and affects man
* 2. Type B is very virulent, it is found in pigs but also in fish, vegetables and milk. It develops in man.
* 3. Type C: its pathogenicity is poor and rarely affects men, but affects birds. Are three toxins C1, C2 and C3. The C1 is a neurotoxin.
* 4. Type D: rarely affects the human species, but in cattle and horses.
* 5. Type E is very virulent.
* 6. Type F: this would be a subgroup of type E or of a mutant, is found in fish.
* 7. Type G, was isolated from a corn boss.
Are protein toxins, heat-labile, and can become toxoids. Its production requires anaerobic conditions and is optimal at pH 7 and 30 ^0 C. Not all types of C. given botulinum human poisonings, only types A, B and E.
The mechanism by which the toxin functions occur after it has passed through the intestinal lining and is transported in the blood to neuromuscular junctions and synaptic blocking the production of acetylcholine. The interruption of nerve causes irreversible relaxation of muscles, causing flaccid paralysis and respiratory arrest after.
Botulinum toxin is not destroyed by proteases of the digestive tract because it is protected by complex formation with other proteins. In fact, the intestinal protease activated toxin.
Botulinum toxin is used in some cosmetics to stretch wrinkles.
Botulism is a result of ingestion of food poisoning which was present in the vegetative cell and the toxin produced. Where food is commonly are vacuum packed, smoked or spiced and eaten without cooking first. There are four types:
* 1. CAUSED BY FOOD: It is caused by a neurotoxin. The most common offending foods are vacuum-packed food. Common canned
* 2. BY INJURIES: Contamination with dirt or sand, introduction of spores, open fractures treated improperly.
* 3. CHILDREN: Attacks on children under 1 year. It is caused by ingestion of spores which colonize and produce toxin in the intestinal tract. The intake of honey and corn syrup, which is why it is not advisable to give these foods to children under 12 months old.
* 4. WITHOUT CLASSIFICATION: This is a form of infant botulism that occurs in adults and is associated with abnormalities in the digestive tract.
The incubation period varies from 12 to 36 hours, but can be extended to 8 days in some cases. Symptoms include incoordination of the muscles of the eyes, double vision, inability to swallow, difficulty speaking, poor reflexes, dizziness. Gastrointestinal symptoms such as vomiting, abdominal pain, diarrhea, or congestion. Signs are progressive bulbar paralysis and death occurs from respiratory paralysis or cardiac arrest. There is no fever present. The patient maintains consciousness until death. In patients where the toxin is not there has been recovery, but in patients where the toxin has been developed there is no recovery.
You can try to eliminate the toxin by inducing vomiting or gastrointestinal lavage of botulinum immune globulin that is available only in a limited way.
Should be administered trivalent antitoxin A, B and E, intravenously, use a respirator.
Is important since it carries butyric fermentation or butanediol.
However, aerobic organisms of a food can grow and use oxygen in a container, creating anaerobic conditions conducive to their development and an acidic product can grow C. botulinum, if present, when the acid has been used by other agencies, increasing the pH. It is the toughest of food poisoning microorganisms, as canning industry generally supports all non-acid treated products must meet the basic requirements necessary heat sterilization to destroy C. botulinum. .
Occurs in both vegetative and spore form, the latter being as important from the standpoint of food canning. The vegetative form is easily destroyed at temperatures below 100 o C, while spores, which come from dust and soil, can survive 300 minutes of boiling at 100 ^0 C. These are proteolytic and saccharolytic powers. Botulinum toxin is soluble in water and extremely lethal to humans L vegetative cell produces a toxin that is destroyed by exposure for ten minutes to wet heat at 100 o C.
Is extremely important in soil microbiology, where their species ensures the degradation of organic matter and nitrogen fixation.
Clostridium tetani
Bacillary is an anaerobic bacterium that stains Gram positive fresh crops, but crops grown, stained Gram negative.
It has a flagellum and develops terminal endospore.
Oxygen-sensitive but resistant to heat.
It is the main cause of the disease tetanus.
It is distributed worldwide and specifically in the soil, human and animal intestines, human skin sites where there is dirt or debris in the faeces of horses and other animals feces and contaminated heroin.
Vegetative cells of Clostridium tetani produce and release tetanospasmin especially when lysed. The tetanospamina acts in various ways on the central nervous system.
The most important is when the tetanospamina is released by vegetative cells is directed to the central nervous system by axonal transport or blood flow which is set in the brainstem and spinal cord, where it inhibits the release of neurotransmitters acetylcholine and inhibitors muscle contraction by interfering with neuromuscular transmission, which results in the production of generalized muscle spasms, hyperreflexia and sudden attacks.
Clostridia produce a variety of toxins and enzymes that lead to the infection spreads.
Clostridium tetani is an invasive organism. The spores enter the tissues by contamination of wounds, burns, injuries, umbilical cord or surgical sutures with soil or faeces, administration of drugs, abortions, rusty metal contact, sometimes from the intestinal tract, animal bite as Dog or direct inoculation of infected material that flank the main barrier of defense is the skin.
The loosening of tissue and interference with blood supply, together with the secretion of hyaluronidase tetanospamina and spreads the infection. The germination of spores and vegetative development of toxin-producing microorganisms are favored by:
* 1. Necrotic tissue.
* 2. Salts of calcium and
* 3. Pyogenic infections.
The volume of infected tissue is small, why the disease is toxemia and reach a serious condition resulting in death.
The incubation period varies from 4 to 5 days or several weeks. The disease is characterized by seizures tonic contractions of voluntary muscles, muscle spasms often occur first in the injured area and infected then affect the jaw muscles which contract in such a way that can not open your mouth, there is difficulty swallowing, irritability. Are gradually being affected other voluntary muscles resulting in tonic spasms. It also affects the autonomic nervous system causing sweating, cardiac arrhythmias and blood pressure fluctuations. Any external stimulus can trigger a seizure tetanus. The patient is fully conscious and the pain can be severe. Death ensues. Usually. By interfering with the mechanics of breathing. The mortality rate in generalized tetanus is very high. This disease is common in rural areas, warm and humid.
The prevention of tetanus depends on:
* 1. Active immunization with tetanus.
* 2. Proper treatment of wounds contaminated with soil etc.,
* 3. Antitoxin and Prophylactic
* 4. Administration of penicillin.
Dose of 3.000 to 10.000 units of tetanus immune globulin, before it is fixed to the nervous system, otherwise the treatment is no longer effective.
Clostridium difficile
Causative agent of pseudomembranous colitis
The administration of antibiotics permits the growth of C. drug-resistant difficile, which produces two toxins. The toxin A powerful enterotoxin that binds to the brush border membrane of the intestine, their receptor sites. Toxin B, potent cytotoxin, whose receptors are unknown. The two toxins are found in the stool of individuals with the disorder. Not all strains of C. synthesized difficile toxins.
Pseudomembranous colitis is the formation of microabscesses located in an area of the intestine in patients with diarrhea.
Occurs in patients with antibiotic treatment, although many antibiotics have been associated with pseudomembranous colitis, the most common are ampicillin and clindamycin.
Levels are present watery or bloody diarrhea and the patient has abdominal cramps, fever and leukocytosis
The disease is treated with antibiotic administration causes discontinuous with metronidazole or oral vancomycin.
Clostridium perfringens
Causative agent of gas gangrene.
Causal agent of necrotic enteritis.
Present in the genital tract of 5% of women.
The toxin is synthesized in the intestine.
The action of the enterotoxin of C. perfringens includes a disorder in the jejunum and ileum, grade very evident with fluids and electrolytes lost in diarrhea. The precise mechanism has not been established, Tal enterotoxin is formed when ingested large amounts of clostridia and induces severe diarrhea in 6 to 18 hours.
Cause foodborne illnesses, primarily by ingestion of clostridia growing in hot meat dishes.
Cause tissue injury due to toxin production, but gas gangrene is a mixed infection comprising proteolytic clostridia, and Gram negative cocci
In women had abortions after instrumentation.
Occurrence of diarrhea without vomiting or fever in 6 to 18 hours. The illness lasts 1 or 2 days.
Tissue injury produces crepitus in the subcutaneous tissue and muscle foul exudation, necrosis, progressive fever, hemolysis, toxemia and death.
Based early amputation surgery and administration of antitoxin.
Sometimes the infection results in only fasciitis or anaerobic cellulitis.
Clostridium perfringens is a cause of enterotoxemia, haemorrhagic frequently in sheep, lambs, calves, sheep and goats.
This disease is similar to that produced by B. cereus and tends to resolve itself.
Other species that cause gas gangrene are:
C.novyi, C. septicum, C. sporogenes, C. and C. sordelli histolyticum.
Clostridium sordellii
Inhabitant of the female genital tract flora, has been involved in the deaths of more than a dozen women with toxic shock syndrome after delivery.
Clostridium thermocellum
Important industry and that is causing the butyric fermentation. Can produce ethanol from certain wastes, making it a possible candidate in the use and production of ethanol. With no oxygen requirements and being thermophilic, reduces cooling costs.
Clostridium acetobutylicum
Also known as the Weizmann organism. It is important in the industry was first used by Chaim Weizmann to produce acetone and biobutanol from starch in 1916 in the production of gunpowder and TNT.
Important in the industry and recently discovered in commercial chicken wastes, can produce ethanol from a single carbon sources, including Syngas, a mixture of carbon dioxide and hydrogen can be generated from the partial combustion of biomass and therefore fossil fuel. The use of these bacteria to produce ethanol and is a project in various power plants.
* 1. C. aerotolerans
* 2. C. butyricum
* 3. C. colicanis
* 4. C. formicaceticum
* 5. C. Laramie
* 6. C. novyi
* 7. C. piliform
* 8. C. sporogenes
* 9. C. tyrobutyricum
Gender heliobacterium
Anaerobic sensitive to oxygen and does not tolerate sulfur. Flagellum, rod-shaped curves. Heliophilum is especially interesting because its coconut-shaped cells are grouped in clusters, moving as a unit.
Produces a unique form of a pigment called bacteriochlorophyll is important to make the necessary photoreactions and has an absorption spectrum.
It draws power heterotrophic as light or chemicals but does not release oxygen. Fixes nitrogen and it is this very important activity in the fertilization of rice fields. However, we can develop in the dark by fermentation of pyruvate.
Some are extremophiles as heliobacterium modesticaldum, alkaliphiles and heliorestis.
They are Gram positive, but are similar in the absence of an outer membrane and the ability to form endospores. Is at the membrane where they perform photosynthesis. They are the only group associated with Gram-positive bacteria that perform photosynthesis.
They are common in soil, mainly in agricultural soils, particularly where rice is harvested, apparently not water. Suggests that can grow under a carpet of cyanobacteria.
It is important in the evolution of photosynthesis and that could explain the unusually high and low light pigment containing heliobacteria and reveal new mechanisms of power generation.
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