Streptococcus is a lagenus of spherical Gram-positive bacteria, belonging to the phylum Firmicutes^[1] and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek streptos, meaning easily bent or twisted, like a chain. Contrast this with staphylococci, which divide along multiple axes and generate grape-like clusters of cells. For other uses, see Genus (disambiguation). ... For other uses, see Sphere (disambiguation). ... Gram-positive bacteria are those that are stained dark blue or violet by gram staining, in contrast to gram-negative bacteria, which are not affected by the stain. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Phylum (plural: phyla) is a taxon used in the classification of animals, adopted from the Greek phylai the clan-based voting groups in Greek city-states. ... Classes Bacilli Clostridia Mollicutes The Firmicutes are a division of bacteria, most of which have Gram-positive cell wall structure. ... Species L. acidophilus L. bulgaricus L. plantarum L.reuteri etc. ... This does not adequately cite its references or sources. ... A coordinate axis is one of a set of vectors that defines a coordinate system. ... Species S. aureus S. caprae S. epidermidis S. haemolyticus S. hominis S. lugdunensis S. pettenkoferi S. saprophyticus S. warneri S. xylosus Staphylococcus (in Greek staphyle means bunch of grapes and coccos means granule) is a genus of Gram-positive bacteria. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the...

Streptococci are oxidase– and catalase–negative. An oxidase is any enzyme that catalyzes an oxidation/reduction reaction involving molecular oxygen (O2) as the electron acceptor. ... Catalase (human erythrocyte catalase: PDB 1DGF, EC 1. ...

Pathogenesis

In addition to strep throat , certain Streptococcus species are responsible for many cases of meningitis, bacterial pneumonia, endocarditis, erysipelas and necrotizing fasciitis (the 'flesh-eating' bacterial infections). However, many streptococcal species are non-pathogenic. Streptococci are also part of the normal commensal flora of the mouth, skin, intestine, and upper respiratory tract of humans. Strep throat (or Streptococcal pharyngitis, or Streptococcal Sore Throat) is a form of Group A streptococcal infection that affects the pharynx. ... Meningitis is the inflammation of the protective membranes covering the central nervous system, known collectively as the meninges. ... Bacterial pneumonia is an infection of the lungs by bacteria. ... Endocarditis is an inflammation of the inner layer of the heart, the endocardium. ... Necrotizing fasciitis or fasciitis necroticans, commonly known as flesh-eating bacteria, is a rare infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissue. ... Commensalism is a term employed in ecology to describe a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. ... In microbiology, flora (plural: floras or floræ) refers to the collective bacteria and other microorganisms in an ecosystem (usually an animal host or a single part of its body). ...

As a rule, individual species of Streptococcus are classified based on their hemolytic properties (breakdown of red blood cells in a laboratory).^[2] Alpha hemolysis is caused by a reduction of iron in hemoglobin, giving it a greenish color on blood agar. Beta-only hemolysis is complete rupture of red blood cells, giving distinct, wide, clear areas around bacterial colonies on blood agar. Other streptococci are labeled as gamma hemolytic, actually a misnomer, as no hemolysis takes place. Examples of alpha (top), beta (middle), and gamma (bottom) hemolysis on sheep blood agar plates Hemolysis is used in the empirical identification of microorganisms based on the ability of bacterial colonies grown on agar plates to break down red blood cells in the culture. ...

Beta-hemolytic streptococci are further characterised via the Lancefield serotyping - based on specific carbohydrates in the bacterial cell wall.^[3] These are named Lancefield groups A to T, although some species, such as S. pneumoniae, do not express Lancefield antigens. See the related article on Rebecca Lancefield. In the medical setting, the most important groups are the alpha-hemolytic streptococci, S. pneumoniae and Streptococcus Viridans-group, and the beta-hemolytic streptococci of Lancefield groups A and B (also known as “Group A Strep” and “Group B Strep”). A serovar or serotype is a grouping of microorganisms or viruses based on their cell surface antigens. ... Rebecca Craighill Lancefield (January 5, 1895 - March 3, 1981) was a prominent American microbiologist. ...

Alpha-Hemolytic Streptococcus

Pneumococci

• S. pneumoniae, a leading cause of bacterial pneumonia, otitis media and meningitis.

Binomial name (Klein 1884) Chester 1901 Streptococcus pneumoniae, or pneumococcus, is a Gram-positive, alpha-hemolytic diplococcus bacterium and a member of the genus Streptococcus. ... This article is about human pneumonia. ... Meningitis is the inflammation of the protective membranes covering the central nervous system, known collectively as the meninges. ...

Viridans and Others

• S. mutans, a contributor to dental caries
• S. viridans, a cause of endocarditis and dental abscesses
• S. thermophilus, used in the manufacture of some cheeses and yogurts
• S. constellatus, occasional human pathogen, notable as colonies grown on blood agar smell strongly of caramel

Binomial name Streptococcus mutans Clarke 1924 Streptococcus mutans is a Gram-positive, facultatively anaerobic bacteria commonly found in the human oral cavity and is a significant contributor to tooth decay. ... Streptococcus viridans is a large group of generally non-pathogenic Streptococcus that are all alpha hemolytic and produce a green (hence the name) coloration on blood agar. ... Endocarditis is an inflammation of the inner layer of the heart, the endocardium. ... A tooth abscess or root abscess is pus enclosed in the tissues of the jaw bone at the tip of an infected tooth. ... This article belongs in one or more categories. ... This does not adequately cite its references or sources. ...

Beta-Hemolytic Streptococci

Group A

S. pyogenes (also known as GAS) is the causative agent in Group A streptococcal infections, (GAS) including streptococcal pharyngitis ("strep throat"), acute rheumatic fever, scarlet fever, acute glomerulonephritis and necrotizing fasciitis. If strep throat is not treated, it can develop into rheumatic fever, a disease that affects the joints and heart valves. Other Streptococcus species may also possess the Group A antigen, but human infections by non-S. pyogenes GAS strains (some S. dysgalactiae subsp. equisimilis and S. anginosus Group strains) appear to be uncommon. Binomial name Rosenbach 1884 Streptococcus pyogenes is a spherical gram-positive bacteria that grows in long chains [1] and is the cause of Group A streptococcal infections. ... The group A streptococcus bacterium (Streptococcus pyogenes, or GAS) is a form of Streptococcus bacteria responsible for most cases of streptococcal illness. ... Rheumatic fever is an inflammatory disease which may develop after a Group A streptococcal infection (such as strep throat or scarlet fever) and can involve the heart, joints, skin, and brain. ... Glomerulonephritis, also known as glomerular nephritis and abbreviated GN, is a primary or secondary immune-mediated renal disease characterized by inflammation of the glomeruli, or small blood vessels in the kidneys. ... Necrotizing fasciitis or fasciitis necroticans, commonly known as flesh-eating bacteria, is a rare infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissue. ... Strep throat (or Streptococcal pharyngitis, or Streptococcal Sore Throat) is a form of Group A streptococcal infection that affects the pharynx. ... Rheumatic fever is an inflammatory disease which may develop after a Group A streptococcal infection (such as strep throat or scarlet fever) and can involve the heart, joints, skin, and brain. ... For other uses, see Joint (disambiguation). ... Grays Fig. ...

Group A Strep infection is generally diagnosed with a Rapid Strep Test or by culture.

Group B

S. agalactiae, or GBS, causes pneumonia and meningitis in neonates and the elderly, with occasional systemic bacteremia. They can also colonize the intestines and the female reproductive tract, increasing the risk for premature rupture of membranes and transmission to the infant. The American College of Obstetricians and Gynecologists, American Academy of Pediatrics and the Centers for Disease Control recommend all pregnant women between 35 and 37 weeks gestation should be tested for GBS. Women who test positive should be given prophylactic antibiotics during labor, which will usually prevent transmission to the infant.^[4] In the UK, clinicians have been slow to implement the same standards as the US, Australia and Canada. In the UK, only 1% of maternity units test for the presence of Group B Strep.^[5] Although The Royal College of Obstetricians and Gynaecologists issued risk-based guidelines in 2003 (due for review 2006), the implentation of these guidelines has been patchy. Some groups feel that as a result over 75 infants in the UK die each year of GBS related disease and another 600 or so suffer serious infection, most of which could be prevented ^[6] however this is yet to be substantiated by RCT in the UK setting and, given the evidence for the efficacy of testing and treating from other countries, it may be that the large-scale trial necessary would receive neither funding nor ethics approval.^[7] Binomial name Lehmann and Neumann, 1896 Streptococcus agalactiae also known as Group B Streptococcus is a gram-positive streptococcus characterized by the presence of group B Lancefield antigen. ... This article is about human pneumonia. ... Meningitis is the inflammation of the protective membranes covering the central nervous system, known collectively as the meninges. ... A human infant The word Infant derives from the Latin in-fans, meaning unable to speak. ... Old age consists of ages nearing the average lifespan of human beings, and thus the end of the human life cycle. ... Bacteremia (Bacteræmia in British English, also known as blood poisoning or toxemia) is the presence of bacteria in the blood. ... The Centers for Disease Control and Prevention (CDC) in Atlanta is recognized as the lead United States agency for protecting the public health and safety of people by providing credible information to enhance health decisions, and promoting health through strong partnerships with state health departments and other organizations. ... Motto: (traditional) In God We Trust (official, 1956–present) Anthem: The Star-Spangled Banner Capital Washington, D.C. Largest city New York City Official language(s) None at the federal level; English de facto Government Federal Republic  - President George W. Bush (R)  - Vice President Dick Cheney (R) Independence - Declared - Recognized...

Group C

Includes S. equi, which causes strangles in horses,^[8] and S. zooepidemicus, which causes infections in several species of mammals including cattle and horses. This can also cause death in chickens and moose. Many mountaineers from Canada have found corpses of moose lying in the middle of the road; post-mortem tests have found group c streptococcus in their blood. Strangles is a contagious, upper respiratory tract infection of horses and other equines caused by a bacterium, Streptococcus equi. ...

Group D (Enterococci) *variable in hemolysis

Many former Group D streptococci have been reclassified and placed in the genus Enterococcus (includes S. faecalis, S. faciem, S. durans, and S. avium).^[9] For example, Streptococcus faecalis is now Enterococcus faecalis. Species E. faecalis etc. ... Enterococci, traditionally viewed as Gram-positive commensal bacteria inhabiting the alimentary canals of humans and animals, are now acknowledged to be organisms capable of causing life-threatening infections in humans, especially in the nosocomial (hospital) environment. ...

The remaining non-enterococcal Group D strains include Streptococcus bovis and Streptococcus equinus. Streptococcus bovis is a rare cause of neonatal septicaemia and meningitis. ...

Non-Hemolytic Streptococci

Non-hemolytic streptococci rarely cause disease. However, weakly hemolytic group D beta-hemolytic streptococci and Listeria monocytogenes should not be confused with non-hemolytic streptococci. Binomial name Murray (1926) Listeria monocytogenes is a Gram-positive bacterium, in the division Firmicutes, named for Joseph Lister. ...

References

HTML, an initialism of HyperText Markup Language, is the predominant markup language for web pages. ... HTML, an initialism of HyperText Markup Language, is the predominant markup language for web pages. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 9th day of the year in the Gregorian calendar. ... HTML, an initialism of HyperText Markup Language, is the predominant markup language for web pages. ...

External links

• Prevention of Perinatal Group B Streptococcal Disease August 16, 2002 MMWR 2000;49:228-232.
• The Canadian Strep B Foundation
• The UK Group B Strep Support charity