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Alpha Toxin (other)
Alpha toxin or alpha-toxin refers to several different protein toxins produced by bacteria, including: * ''Staphylococcus aureus'' alpha toxin, a membrane-disrupting toxin that creates pores causing hemolysis and tissue damage * ''Clostridium perfringens'' alpha toxin, a membrane-disrupting toxin with phospholipase C activity, which is directly responsible for gas gangrene and myonecrosis *''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. aerugi ...'' alpha toxin {{disambig Bacterial toxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Aureus Alpha Toxin
Alpha-toxin, also known as alpha-hemolysin (Hla), is the major cytotoxic agent released by bacterium '' Staphylococcus aureus'' and the first identified member of the pore forming beta-barrel toxin family. This toxin consists mostly of beta-sheets (68%) with only about 10% alpha-helices. The ''hly'' gene on the ''S. aureus'' chromosome encodes the 293 residue protein monomer, which forms heptameric units on the cellular membrane to form a complete beta-barrel pore. This structure allows the toxin to perform its major function, development of pores in the cellular membrane, eventually causing cell death. Function Alpha-toxin has been shown to play a role in pathogenesis of disease, as ''hly'' knockout strains show reductions in invasiveness and virulence. The dosage of toxin can result in two different modes of activity. Low concentrations of toxin bind to specific, but unidentified, cell surface receptors and form the heptameric pores. This pore allows the exchange of monovale ... [...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] |
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] |
