 |
CAMP Test
The CAMP test (Christie–Atkins–Munch-Peterson) is a test to identify group B β-hemolytic streptococci (''Streptococcus agalactiae'') based on their formation of a substance (CAMP factor) that enlarges the area of hemolysis formed by the β-hemolysin elaborated from ''Staphylococcus aureus''. CAMP factor Although the test is usually used to identify group B streptococcus, there is some evidence that the CAMP factor gene is present in several groups of streptococci, including group A. A similar factor has been identified in ''Bartonella henselae''. Uses The CAMP test can be used to identify ''Streptococcus agalactiae''. Though not strongly beta-hemolytic on its own, group B strep presents with wedge-shaped colonies in the presence of ''Staphylococcus aureus''. It can also be used to identify ''Listeria monocytogenes'' which produces a positive CAMP reaction. Setup # Streak a beta-lysin–producing strain of ''aureus'' down the center of a sheep blood agar plate. # The te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
 |
Hemolysis (microbiology)
Hemolysis (from Greek αιμόλυση, meaning 'blood breakdown') is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly useful in classifying streptococcal species. A substance that causes hemolysis is a '' hemolysin''. Types Alpha-hemolysis When alpha-hemolysis (α-hemolysis) is present, the agar under the colony is light and greenish. ''Streptococcus pneumoniae'' and a group of oral streptococci ( ''Streptococcus'' viridans or viridans streptococci) display alpha hemolysis. This is sometimes called ''green hemolysis'' because of the color change in the agar. Other synonymous terms are ''incomplete hemolysis'' and ''partial hemolysis''. Alpha hemolysis is caused by hydrogen peroxide produced by the bacterium, oxidizing hemoglobin producing the green oxidized derivative methemoglobin. Beta-hemolysis Beta-hemolysis (β-hemolysis), sometimes called ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
 |
Streptococci
''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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
 |
Streptococcus Agalactiae
''Streptococcus agalactiae'' (also known as group B streptococcus or GBS) is a gram-positive coccus (round bacterium) with a tendency to form chains (as reflected by the genus name ''Streptococcus''). It is a beta-hemolytic, catalase-negative, and facultative anaerobe. ''S. agalactiae'' is the most common human pathogen of streptococci belonging to group B of the Rebecca Lancefield classification of streptococci. GBS are surrounded by a bacterial capsule composed of polysaccharides (exopolysacharide). The species is subclassified into ten serotypes (Ia, Ib, II–IX) depending on the immunologic reactivity of their polysaccharide capsule. The plural term group B streptococci (referring to the serotypes) and the singular term group B streptococcus (referring to the single species) are both commonly encountered (even though ''S. halichoeri'' and ''S. pseudoporcinus'' are also group B Streptococci). In general, GBS is a harmless commensal bacterium being part of the human microbio ... [...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 solu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
 |
Hemolysin
Hemolysins or haemolysins are lipids and proteins that cause lysis of red blood cells by disrupting the cell membrane. Although the lytic activity of some microbe-derived hemolysins on red blood cells may be of great importance for nutrient acquisition, many hemolysins produced by pathogens do not cause significant destruction of red blood cells during infection. However, hemolysins are often capable of lysing red blood cells ''in vitro''. While most hemolysins are protein compounds, some are lipid biosurfactants. Properties Many bacteria produce hemolysins that can be detected in the laboratory. It is now believed that many clinically relevant fungi also produce hemolysins. Hemolysins can be identified by their ability to lyse red blood cells ''in vitro''. Not only are the erythrocytes affected by hemolysins, but there are also some effects among other blood cells, such as leucocytes (white blood cells). ''Escherichia coli'' hemolysin is potentially cytotoxic to monocyt ... [...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. aureu ... [...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] |
|
|
Bartonella Henselae
''Bartonella henselae'', formerly ''Rochalimæa henselae'', is a bacterium that is the causative agent of cat-scratch disease (bartonellosis). ''Bartonella henselae'' is a member of the genus ''Bartonella'', one of the most common types of bacteria in the world. It is a facultative intracellular microbe that targets red blood cells. One study showed it invaded the mature blood cells of humans. It infects the host cell by sticking to it using trimeric autotransporter adhesins. In the United States, about 22,000 people(per year?)are diagnosed, most under the age of 20. Most often, it is transmitted from kittens. Diagnosis ''Bartonella henselae'' is a Gram-negative rod. It can be cultured in a lysis-centrifugation blood culture. The presence of bacteria can be detected by Warthin-Starry stain, or by a similar silver stain In pathology, silver staining is the use of silver to selectively alter the appearance of a target in microscopy of histological sections; in temperature gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
|
_409-14%2C_Figure_1.png "Click for more on -> Listeria Monocytogenes") |
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 Bacillot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
 |
Dash
The dash is a punctuation mark consisting of a long horizontal line. It is similar in appearance to the hyphen but is longer and sometimes higher from the Baseline (typography), baseline. The most common versions are the endash , generally longer than the hyphen but shorter than the minus sign; the emdash , longer than either the en dash or the minus sign; and the horizontalbar , whose length varies across typefaces but tends to be between those of the en (typography), en and Em (typography), em dashes. History In the early 1600s, in Nicholas Okes, Okes-printed play (theatre), plays of William Shakespeare, dashes are attested that indicate a thinking pause, interruption, mid-speech realization, or change of subject. The dashes are variously longer (as in King Lear reprinted 1619) or composed of hyphens (as in Othello printed 1622); moreover, the dashes are often, but not always, prefixed by a comma, colon, or semicolon. In 1733, in Jonathan Swift's ''On Poetry'', the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
 |
Hyphen
The hyphen is a punctuation mark used to join words and to separate syllables of a single word. The use of hyphens is called hyphenation. ''Son-in-law'' is an example of a hyphenated word. The hyphen is sometimes confused with dashes ( figure dash , en dash , em dash , horizontal bar ), which are longer and have different uses, or with the minus sign , which is also longer and more vertically centred in some typefaces. Although hyphens are not to be confused with en dashes, there are some overlaps in usage (in which either a hyphen or an en dash may be acceptable, depending on user preference, as discussed below). In addition, the hyphen often substitutes for the en dash elsewhere in informal writing. As an orthographic concept, the hyphen is a single entity. In terms of character encoding and display, it is represented by any of several characters and glyphs, including the Unicode hyphen (shown at the top of the infobox on this page), the hyphen-minus, the soft ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |