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Streptolysin
Streptolysins are two hemolytic exotoxins from ''Streptococcus''. Types include streptolysin O (SLO; ''slo''), which is oxygen-labile, and streptolysin S (SLS; ''sagA''), which is oxygen-stable. SLO is part of the thiol-activated cytolysin family. It is hemolytically active only in a reversibly reduced state. It is antigenic, so its antibody antistreptolysin O can be detected in an antistreptolysin O titre. SLS is stable in the presence of oxygen. It is not antigenic due to its small size. It is sometimes considered a bacteriocin due to similarities in the synthesis pathway. Streptolysin O Streptolysin O (SLO; ''slo),'' is a bacterial toxin that has four protein domains which is known to make the plasma membranes in animal cells permeable. It does this by creating pore complexes within the membrane by first binding a monomer to the cholesterol found in the target membrane and then forming an oligomeric transmembrane pore. This toxin excreted by a Gram-positive bacteria ''St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antistreptolysin O
Anti-streptolysin O (ASO or ASLO) is the antibody made against streptolysin O, an immunogenic, oxygen-labile streptococcal hemolytic exotoxin produced by most strains of group A and many strains of groups C and G '' Streptococcus'' bacteria. The "O" in the name stands for ''oxygen-labile''; the other related toxin being oxygen-stable streptolysin-S. The main function of streptolysin O is to cause hemolysis (the breaking open of red blood cells)—in particular, beta-hemolysis. Increased levels of ASO titre in the blood could cause damage to the heart and joints. In most cases, penicillin is used to treat patients with increased levels of ASO titre. Clinical significance When the body is infected with streptococci, it produces antibodies against the various antigens that the streptococci produce. ASO is one such antibody. A raised or rising levels can indicate past or present infection. Historically it was one of the first bacterial markers used for diagnosis and follow up of rhe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antistreptolysin O Titre
Anti-streptolysin O (ASO or ASLO) is the antibody made against streptolysin O, an immunogenic, oxygen-labile streptococcal hemolytic exotoxin produced by most strains of group A and many strains of groups C and G '' Streptococcus'' bacteria. The "O" in the name stands for ''oxygen-labile''; the other related toxin being oxygen-stable streptolysin-S. The main function of streptolysin O is to cause hemolysis (the breaking open of red blood cells)—in particular, beta-hemolysis. Increased levels of ASO titre in the blood could cause damage to the heart and joints. In most cases, penicillin is used to treat patients with increased levels of ASO titre. Clinical significance When the body is infected with streptococci, it produces antibodies against the various antigens that the streptococci produce. ASO is one such antibody. A raised or rising levels can indicate past or present infection. Historically it was one of the first bacterial markers used for diagnosis and follow up of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-streptolysin O
Anti-streptolysin O (ASO or ASLO) is the antibody made against streptolysin O, an immunogenic, oxygen-labile streptococcal hemolytic exotoxin produced by most strains of group A and many strains of groups C and G ''Streptococcus'' bacteria. The "O" in the name stands for ''oxygen-labile''; the other related toxin being oxygen-stable streptolysin-S. The main function of streptolysin O is to cause hemolysis (the breaking open of red blood cells)—in particular, beta-hemolysis. Increased levels of ASO titre in the blood could cause damage to the heart and joints. In most cases, penicillin is used to treat patients with increased levels of ASO titre. Clinical significance When the body is infected with streptococci, it produces antibodies against the various antigens that the streptococci produce. ASO is one such antibody. A raised or rising levels can indicate past or present infection. Historically it was one of the first bacterial markers used for diagnosis and follow up of rhe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcal Proteins
''Streptococcus'' is a genus of gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes (capable of growth both aerobically and anaerobically). The term was coined in 1877 by Viennese surgeon Albert Theodor Billroth (1829–1894), by combining the prefix "strepto-" (from ), together with the suffix "-coccus" (from Modern , from .) In 1984, many bacteria formerly grouped in the genus ''Streptococcus'' were separated out into the genera ''Enterococcus'' and ''Lactococcus''. Currently, over 50 species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Pyogenes
''Streptococcus pyogenes'' is a species of Gram-positive, aerotolerant bacteria in the genus '' Streptococcus''. These bacteria are extracellular, and made up of non-motile and non-sporing cocci (round cells) that tend to link in chains. They are clinically important for humans, as they are an infrequent, but usually pathogenic, part of the skin microbiota that can cause Group A streptococcal infection. ''S. pyogenes'' is the predominant species harboring the Lancefield group A antigen, and is often called group A ''Streptococcus'' (GAS). However, both '' Streptococcus dysgalactiae'' and the '' Streptococcus anginosus'' group can possess group A antigen as well. Group A streptococci, when grown on blood agar, typically produce small (2–3 mm) zones of beta-hemolysis, a complete destruction of red blood cells. The name group A (beta-hemolytic) ''Streptococcus'' (GABHS) is thus also used. The species name is derived from Greek words meaning 'a chain' () of berri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus
''Streptococcus'' is a genus of gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes (capable of growth both aerobically and anaerobically). The term was coined in 1877 by Viennese surgeon Albert Theodor Billroth (1829–1894), by combining the prefix "strepto-" (from ), together with the suffix "-coccus" (from Modern , from .) In 1984, many bacteria formerly grouped in the genus ''Streptococcus'' were separated out into the genera '' Enterococcus'' and '' Lactococcus''. Currently, over 50 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group A Streptococcal Infection
Group A streptococcal infections are a number of infections with ''Streptococcus pyogenes'' a group A streptococcus (GAS). ''S. pyogenes'' is a species of beta-hemolytic gram-positive bacteria that is responsible for a wide range of infections that are mostly common and fairly mild. If the bacteria enter the bloodstream an infection can become severe and life-threatening, and is called an invasive GAS (iGAS). Infection of GAS may spread through direct contact with mucus or sores on the skin. GAS infections can cause over 500,000 deaths per year. Despite the emergence of antibiotics as a treatment for group A streptococcus, cases of iGAS are an increasing problem, particularly on the continent of Africa. There are many other species of ''Streptococcus'', including Group B streptococcus ''Streptococcus agalactiae'', and ''Streptococcus pneumoniae'', which cause other types of infections. Several virulence factors contribute to the pathogenesis of GAS, such as M protein, hemolysin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiol-activated Cytolysin
The thiol-activated Cholesterol-dependent Cytolysin (CDC) familyTC# 1.C.12 is a member of the MACPF superfamily. Cholesterol dependent cytolysins are a family of β-barrel pore-forming exotoxins that are secreted by gram-positive bacteria. CDCs are secreted as water-soluble monomers of 50-70 kDa, that when bound to the target cell, form a circular homo-oligomeric complex containing as many as 40 (or more) monomers. Through multiple conformational changes, the β-barrel transmembrane structure (~250 Å in diameter depending on the toxin) is formed and inserted into the target cell membrane. The presence of cholesterol in the target membrane is required for pore formation, though the presence of cholesterol is not required by all CDCs for binding. For example, intermedilysin (ILYTC# 1.C.12.1.5 secreted by '' Streptococcus intermedius'' will bind only to target membranes containing a specific protein receptor, independent of the presence of cholesterol, but cholesterol is required by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligomeric
In chemistry and biochemistry, an oligomer () is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers.Quote: ''Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular mass.'' The name is composed of Greek elements '' oligo-'', "a few" and '' -mer'', "parts". An adjective form is ''oligomeric''. The oligomer concept is contrasted to that of a polymer, which is usually understood to have a large number of units, possibly thousands or millions. However, there is no sharp distinction between these two concepts. One proposed criterion is whether the molecule's properties vary significantly with the removal of one or a few of the units. An oligomer with a specific number of units is referred to by the Greek prefix denoting that number, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
