|
Lecithinase
Lecithinase is a type of phospholipase that acts upon lecithin. It can be produced by ''Clostridium perfringens'', ''Staphylococcus aureus'', ''Pseudomonas aeruginosa'' or ''Listeria monocytogenes''. ''C. perfringens'' alpha toxin (lecithinase) causes myonecrosis and hemolysis Hemolysis or haemolysis (), also known by several other names, is the rupturing ( lysis) of red blood cells (erythrocytes) and the release of their contents ( cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in viv .... The lecithinase of ''S. aureus'' is used in detection of coagulase-positive strains, because of high link between lecithinase activity and coagulase activity. References EC 3.1.4 {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clostridium Perfringens
''Clostridium perfringens'' (formerly known as ''C. welchii'', or ''Bacillus welchii'') is a Gram-positive, rod-shaped, anaerobic, spore-forming pathogenic bacterium of the genus '' Clostridium''. ''C. perfringens'' is ever-present in nature and can be found as a normal component of decaying vegetation, marine sediment, the intestinal tract of humans and other vertebrates, insects, and soil. It has the shortest reported generation time of any organism at 6.3 minutes in thioglycolate medium. ''Clostridium perfringens'' is one of the most common causes of food poisoning in the United States, alongside norovirus, ''Salmonella'', '' Campylobacter'', and ''Staphylococcus aureus''. However, it can sometimes be ingested and cause no harm. Infections due to ''C. perfringens'' show evidence of tissue necrosis, bacteremia, emphysematous cholecystitis, and gas gangrene, also known as clostridial myonecrosis. The specific name ''perfringens'' is derived from the Latin ''per'' (meaning " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phospholipase
A phospholipase is an enzyme that hydrolyzes phospholipids into fatty acids and other lipophilic substances. Acids trigger the release of bound calcium from cellular stores and the consequent increase in free cytosolic Ca2+, an essential step in calcium signaling to regulate intracellular processes. There are four major classes, termed A, B, C, and D, which are distinguished by the type of reaction which they catalyze: *Phospholipase A **Phospholipase A1 – cleaves the ''sn''-1 acyl chain (where ''sn'' refers to stereospecific numbering). **Phospholipase A2 – cleaves the ''sn''-2 acyl chain, releasing arachidonic acid. * Phospholipase B – cleaves both ''sn''-1 and ''sn''-2 acyl chains; this enzyme is also known as a lysophospholipase. *Phospholipase C – cleaves before the phosphate, releasing diacylglycerol and a phosphate-containing head group. PLCs play a central role in signal transduction, releasing the second messenger inositol triphosphate. * Phospholipase D � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lecithin
Lecithin (, from the Greek ''lekithos'' "yolk") is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues which are amphiphilic – they attract both water and fatty substances (and so are both hydrophilic and lipophilic), and are used for smoothing food textures, emulsifying, homogenizing liquid mixtures, and repelling sticking materials. Lecithins are mixtures of glycerophospholipids including phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and phosphatidic acid. Lecithin was first isolated in 1845 by the French chemist and pharmacist Théodore Gobley. In 1850, he named the phosphatidylcholine ''lécithine''. Gobley originally isolated lecithin from egg yolk – λέκιθος ''(lekithos)'' is "egg yolk" in Ancient Greek – and established the complete chemical formula of phosphatidylcholine in 1874; in between, he demonstrated the presence of lecithin in a variety of biologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. Although ''S. aureus'' usually acts as a commensal of the human microbiota, it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. ''S. aureus'' is one of the leading pathogens for deaths associated with antimicrobial resistance and the emergence of antibiotic-resistant strains, such as methicillin-resistant ''S. aureus'' (MRSA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonas Aeruginosa
''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aeruginosa'' is a multidrug resistant pathogen recognized for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses – hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes. The organism is considered opportunistic insofar as serious infection often occurs during existing diseases or conditions – most notably cystic fibrosis and traumatic burns. It generally affects the immunocompromised but can also infect the immunocompetent as in hot tub folliculitis. Treatment of ''P. aeruginosa'' infections can be difficult due to its natural resistance to antibiotics. When more advanced antibiotic drug regimens are needed adverse effects may re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Listeria Monocytogenes
''Listeria monocytogenes'' is the species of pathogenic bacteria that causes the infection listeriosis. It is a facultative anaerobic bacterium, capable of surviving in the presence or absence of oxygen. It can grow and reproduce inside the host's cells and is one of the most virulent foodborne pathogens: 20 to 30% of foodborne listeriosis infections in high-risk individuals may be fatal. Responsible for an estimated 1,600 illnesses and 260 deaths in the United States annually, listeriosis ranks third in total number of deaths among foodborne bacterial pathogens, with fatality rates exceeding even '' Salmonella'' spp. and ''Clostridium botulinum''. In the European Union, listeriosis follows an upward trend that began in 2008, causing 2,161 confirmed cases and 210 reported deaths in 2014, 16% more than in 2013. Listeriosis mortality rates are also higher in the EU than for other foodborne pathogens. ''Listeria monocytogenes'' is a Gram-positive bacterium, in the phylum Bacillota, n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clostridium Perfringens Alpha Toxin
''Clostridium perfringens'' alpha toxin is a toxin produced by the bacterium ''Clostridium perfringens'' (''C. perfringens'') and is responsible for gas gangrene and myonecrosis in infected tissues. The toxin also possesses hemolytic activity. Clinical significance This toxin has been shown to be the key virulence factor in infection with ''C. perfringens''; the bacterium is unable to cause disease without this toxin. Further, vaccination against the alpha toxin toxoid protects mice against ''C. perfringens'' gas gangrene. As a result, knowledge about the function of this particular protein greatly aids understanding of myonecrosis. Structure and homology The alpha toxin has remarkable similarity to toxins produced by other bacteria as well as natural enzymes. There is significant homology with phospholipase C enzymes from ''Bacillus cereus'', ''C. bifermentans'', and ''Listeria monocytogenes''. The C terminal domain shows similarity with non-bacterial enzymes such as pancreati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myonecrosis
Gas gangrene (also known as clostridial myonecrosis and myonecrosis) is a bacterial infection that produces tissue gas in gangrene. This deadly form of gangrene usually is caused by ''Clostridium perfringens'' bacteria. About 1,000 cases of gas gangrene are reported yearly in the United States. Myonecrosis is a condition of necrotic damage, specific to muscle tissue. It is often seen in infections with ''C. perfringens'' or any of myriad soil-borne anaerobic bacteria. Bacteria cause myonecrosis by specific exotoxins. These microorganisms are opportunistic and, in general, enter the body through significant skin breakage. Gangrenous infection by soil-borne bacteria was common in the combat injuries of soldiers well into the 20th century, because of non-sterile field surgery and the basic nature of care for severe projectile wounds. Other causes of myonecrosis include envenomation by snakes of the genus ''Bothrops'' (family Viperidae), ischemic necrosis, caused by vascular blockage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemolysis
Hemolysis or haemolysis (), also known by several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo or in vitro. One cause of hemolysis is the action of hemolysins, toxins that are produced by certain pathogenic bacteria or fungi. Another cause is intense physical exercise. Hemolysins damage the red blood cell's cytoplasmic membrane, causing lysis and eventually cell death. Etymology From hemo- + -lysis, from , "blood") + , "loosening"). Inside the body Hemolysis inside the body can be caused by a large number of medical conditions, including some parasites (''e.g.'', ''Plasmodium''), some autoimmune disorders (''e.g.'', autoimmune haemolytic anaemia, drug-induced hemolytic anemia, atypical hemolytic uremic syndrome (aHUS)), some genetic disorders (''e.g.'', Sickle-cell disease or G6PD deficiency), or blood with too low a solute conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_409-14%2C_Figure_1.png "Click for more on -> Listeria Monocytogenes")
