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65-652: Streptococcus is a genus of gram-positive 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 , thus when growing they tend to form pairs or chains, which 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

130-452: A serotype classification (that is, describing specific carbohydrates present on the bacterial cell wall). The 21 described serotypes are named Lancefield groups A to W (excluding E, I and J). This system of classification was developed by Rebecca Lancefield , a scientist at Rockefeller University . In the medical setting, the most important groups are the alpha-hemolytic streptococci S. pneumoniae and Streptococcus viridans groups, and

195-557: A species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in the nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

260-651: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

325-628: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

390-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

455-650: A strain of Staphylococcus . This is called the CAMP test . Streptococcus agalactiae displays this property. Clostridium perfringens can be identified presumptively with this test. Listeria monocytogenes is also positive on sheep's blood agar. Group A S. pyogenes is the causative agent in a wide range of group A streptococcal infections (GAS). These infections may be noninvasive or invasive. The noninvasive infections tend to be more common and less severe. The most common of these infections include streptococcal pharyngitis (strep throat) and impetigo . Scarlet fever

520-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

585-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

650-435: Is a complex process dependent on the expression of numerous genes. To be capable of transformation a bacterium must enter a special physiologic state referred to as competence . S. pneumoniae , S. mitis and S. oralis can become competent, and as a result actively acquire homologous DNA for transformation by a predatory fratricidal mechanism This fratricidal mechanism mainly exploits non-competent siblings present in

715-620: Is actually a gram-positive bacillus) should not be confused with nonhemolytic streptococci. Group F streptococci were first described in 1934 by Long and Bliss among the "minute haemolytic streptococci". They are also known as Streptococcus anginosus (according to the Lancefield classification system) or as members of the S. milleri group (according to the European system). These streptococci are usually, but not exclusively, beta-hemolytic. Streptococcus dysgalactiae subsp. canis

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780-481: Is also a member of group C, beta-haemolytic streptococci that can cause pharyngitis and other pyogenic infections similar to group A streptococci . Group C streptococcal bacteria are considered zoonotic pathogens, meaning infection can be passed from animal to human. Many former group D streptococci have been reclassified and placed in the genus Enterococcus (including E. faecalis , E. faecium , E. durans , and E. avium ). For example, Streptococcus faecalis

845-440: Is also termed incomplete hemolysis or partial hemolysis because the cell membranes of the red blood cells are left intact. This is also sometimes called green hemolysis because of the color change in the agar. Beta-hemolysis (β-hemolysis), sometimes called complete hemolysis , is a complete lysis of red cells in the media around and under the colonies: the area appears lightened (yellow) and transparent. Streptolysin, an exotoxin,

910-514: Is another example of Group A noninvasive infection. The invasive infections caused by group A beta-hemolytic streptococci tend to be more severe and less common. This occurs when the bacterium is able to infect areas where it is not usually found, such as the blood and organs . The diseases that may be caused include streptococcal toxic shock syndrome , necrotizing fasciitis , pneumonia , and bacteremia . Globally, GAS has been estimated to cause more than 500,000 deaths every year, making it one of

975-612: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

1040-436: Is generally diagnosed with a rapid strep test or by culture. S. agalactiae , or group B streptococcus , GBS , causes pneumonia and meningitis in newborns and the elderly , with occasional systemic bacteremia . Importantly, Streptococcus agalactiae is the most common cause of meningitis in infants from one month to three months old. They can also colonize the intestines and the female reproductive tract, increasing

1105-462: Is not well characterized. Group G streptococci are also considered zoonotic pathogens. Group H streptococci cause infections in medium-sized canines. Group H streptococci rarely cause human illness unless a human has direct contact with the mouth of a canine. One of the most common ways this can be spread is human-to-canine, mouth-to-mouth contact. However, the canine may lick the human's hand and infection can be spread, as well. In clinical practice,

1170-439: Is now Enterococcus faecalis . E. faecalis is sometimes alpha-hemolytic and E. faecium is sometimes beta hemolytic. The remaining nonenterococcal group D strains include Streptococcus gallolyticus , Streptococcus bovis , Streptococcus equinus and Streptococcus suis . Nonhemolytic streptococci rarely cause illness. However, weakly hemolytic group D beta-hemolytic streptococci and Listeria monocytogenes (which

1235-417: Is particularly useful in classifying streptococcal species. A substance that causes hemolysis is called a hemolysin . 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

1300-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

1365-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

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1430-446: Is the enzyme produced by the bacteria which causes the complete lysis of red blood cells. There are two types of streptolysin: Streptolysin O (SLO) and streptolysin S (SLS). Streptolysin O is an oxygen-sensitive cytotoxin, secreted by most group A Streptococcus (GAS), and interacts with cholesterol in the membrane of eukaryotic cells (mainly red and white blood cells, macrophages, and platelets), and usually results in beta-hemolysis under

1495-453: Is the predominant subspecies encountered. It is a particularly common GGS in humans, although it is typically found on animals. S. phocae is a GGS subspecies that has been found in marine mammals and marine fish species. In marine mammals it has been mainly associated with meningoencephalitis , sepsis , and endocarditis , but is also associated with many other pathologies. Its environmental reservoir and means of transmission in marine mammals

1560-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

1625-824: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

1690-510: The S. mitis and S. pyogenes groups, respectively, while the causative agent of dental caries , Streptococcus mutans , is basal to the Streptococcus group. Recent technological advances have resulted in an increase of available genome sequences for Streptococcus species, allowing for more robust and reliable phylogenetic and comparative genomic analyses to be conducted. In 2018, the evolutionary relationships within Streptococcus

1755-694: The commensal human microbiota of the mouth, skin, intestine, and upper respiratory tract. Streptococci are also a necessary ingredient in producing Emmentaler ("Swiss") cheese . Species of streptococci are classified based on their hemolytic properties. Alpha-hemolytic species cause oxidization of iron in hemoglobin molecules within red blood cells, giving it a greenish color on blood agar. Beta-hemolytic species cause complete rupture of red blood cells. On blood agar, this appears as wide areas clear of blood cells surrounding bacterial colonies. Gamma-hemolytic species cause no hemolysis. Beta-hemolytic streptococci are further classified by Lancefield grouping ,

1820-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

1885-660: The "Mitis-Suis" and "Pyogenes-Equinus-Mutans" clades. The "Mitis-Suis" main clade comprises the Suis subclade and the Mitis clade, which encompasses the Angiosus, Pneumoniae, Gordonii and Parasanguinis subclades. The second main clade, the "Pyogenes-Equinus-Mutans", includes the Pyogenes, Mutans, Salivarius, Equinus, Sobrinus, Halotolerans, Porci, Entericus and Orisratti subclades. In total, 14 distinct subclades have been identified within

1950-485: The Cp (Complutense phage 1, officially Streptococcus virus Cp1 , Picovirinae ) family was discovered with Cp-1 as its first member. Dp-1 and Cp-1 infect both S. pneumoniae and S. mitis . However, the host ranges of most Streptococcus phages have not been investigated systematically. Natural genetic transformation involves the transfer of DNA from one bacterium to another through the surrounding medium. Transformation

2015-473: The French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or the scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of

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2080-446: The administration of intrapartum antibiotics to 15–20% of pregnant women and the prevention of 65–70% of cases of early onset GBS sepsis. This group includes S. equi , which causes strangles in horses, and S. zooepidemicus — S. equi is a clonal descendant or biovar of the ancestral S. zooepidemicus — which causes infections in several species of mammals, including cattle and horses. S. dysgalactiae subsp. dysgalactiae

2145-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

2210-475: The beta-hemolytic streptococci of Lancefield groups A and B (also known as "group A strep" and "group B strep"). Table: Medically relevant streptococci When alpha-hemolysis (α-hemolysis) is present, the agar under the colony will appear dark and greenish due to the conversion of hemoglobin to green biliverdin . Streptococcus pneumoniae and a group of oral streptococci ( Streptococcus viridans or viridans streptococci) display alpha-hemolysis. Alpha-hemolysis

2275-498: The body. This "cross-reaction" causes the body to essentially attack itself and leads to the damage above. A similar autoimmune mechanism initiated by Group A beta-hemolytic streptococcal (GABHS) infection is hypothesized to cause pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) , wherein autoimmune antibodies affect the basal ganglia, causing rapid onset of psychiatric, motor, sleep, and other symptoms in pediatric patients. GAS infection

2340-575: The cell wall. Treatment most often occurs as a 10-day oral antibiotic cycle. For patients with penicillin allergies and those suffering from skin infections, clindamycin can be used. Clindamycin works by disrupting protein synthesis within the cell. Streptococci have been divided into six groups on the basis of their 16S rDNA sequences: S. anginosus, S. gallolyticus, S. mitis, S. mutans, S. pyogenes and S. salivarius . The 16S groups have been confirmed by whole genome sequencing (see figure). The important pathogens S. pneumoniae and S. pyogenes belong to

2405-439: The colonies: the area appears lightened (yellow) and transparent. Streptolysin , an exotoxin, is the enzyme produced by the bacteria which causes the complete lysis of red blood cells. There are two types of streptolysin: Streptolysin O (SLO) and streptolysin S (SLS). Streptolysin O is an oxygen-sensitive cytotoxin, secreted by most Group A streptococcus (GAS) and Streptococcus dysgalactiae , and interacts with cholesterol in

2470-400: 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 (β-hemolysis), sometimes called complete hemolysis , is a complete lysis of red cells in the media around and under

2535-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

2600-737: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

2665-574: The genus Streptococcus were separated out into the genera Enterococcus and Lactococcus . Currently, over 50 species are recognised in this genus. This genus has been found to be part of the salivary microbiome . In addition to streptococcal pharyngitis (strep throat), certain Streptococcus species are responsible for many cases of pink eye , meningitis , bacterial pneumonia , endocarditis , erysipelas , and necrotizing fasciitis (the 'flesh-eating' bacterial infections). However, many streptococcal species are not pathogenic, and form part of

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2730-574: The genus Streptococcus , each supported by reliable branching patterns in phylogenetic trees and by the presence of multiple conserved signature indels in different proteins that are distinctive characteristics of the members of these 14 clades. A summary diagram showing the overall relationships among the Streptococcus based on these studies is depicted in a figure on this page. The genomes of hundreds of species have been sequenced. Most Streptococcus genomes are 1.8 to 2.3 Mb in size and encode 1,700 to 2,300 proteins. Some important genomes are listed in

2795-610: The host immune system from clearing infection. Streptococcus pyogenes , or Group A beta-hemolytic Strep (GAS), displays beta hemolysis. The hemolysis of some weakly beta-hemolytic organisms is enhanced when streaked close to certain beta hemolytic strains of Staphylococcus aureus . This phenomenon is the mechanism behind the CAMP test , a test that was historically used for the identification of Streptococcus agalactiae and Listeria monocytogenes . A modified version of this test, utilizing S. agalactiae instead of S. aureus, called

2860-432: The idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of the same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but

2925-486: The infant. Group III polysaccharide vaccines have been proven effective in preventing the passing of GBS from mother to infant. The United Kingdom has chosen to adopt a risk factor-based protocol, rather than the culture-based protocol followed in the US. Current guidelines state that if one or more of the following risk factors is present, then the woman should be treated with intrapartum antibiotics: This protocol results in

2990-633: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

3055-425: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Beta-hemolysis 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

3120-409: The membrane of eukaryotic cells (mainly red and white blood cells, macrophages, and platelets), and usually results in β-hemolysis under the surface of blood agar. Streptolysin S is an oxygen-stable cytotoxin also produced by most GAS strains which results in clearing on the surface of blood agar. SLS affects immune cells, including polymorphonuclear leukocytes and lymphocytes, and is thought to prevent

3185-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

3250-526: The most common groups of Streptococcus can be distinguished by simple bench tests, such as the PYR test for group A streptococcus . There are also latex agglutination kits which can distinguish each of the main groups seen in clinical practice. Streptococcal infections can be treated with antibiotics from the penicillin family. Most commonly, penicillin or amoxicillin is used to treat strep infection. These antibiotics work by disrupting peptidoglycan production in

3315-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

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3380-541: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

3445-489: The reverse CAMP test can also be used to identify Clostridium perfringens . If an organism does not induce hemolysis, the agar under and around the colony is unchanged, and the organism is called non-hemolytic or said to display gamma-hemolysis (γ-hemolysis). Enterococcus faecalis (formerly called "Group D Strep"), Staphylococcus saprophyticus , and Staphylococcus epidermidis display gamma hemolysis. When some otherwise non-hemolytic bacteria, such as strains of

3510-505: The risk for premature rupture of membranes during pregnancy, and transmission of the organism 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 to be tested for GBS. Women who test positive should be given prophylactic antibiotics during labor, which will usually prevent transmission to

3575-631: The same niche Among highly competent isolates of S. pneumoniae , Li et al. showed that nasal colonization fitness and virulence (lung infectivity) depend on an intact competence system. Competence may allow the streptococcal pathogen to use external homologous DNA for recombinational repair of DNA damages caused by the host's oxidative attack. Genus The composition of a genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including

3640-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

3705-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

3770-462: The surface of blood agar. Streptolysin S is an oxygen-stable cytotoxin also produced by most GAS strains which results in clearing on the surface of blood agar. SLS affects immune cells, including polymorphonuclear leukocytes and lymphocytes, and is thought to prevent the host immune system from clearing infection. Streptococcus pyogenes , or GAS, displays beta hemolysis. Some weakly beta-hemolytic species cause intense hemolysis when grown together with

3835-476: The table. The four species shown in the table ( S. pyogenes, S. agalactiae, S. pneumoniae , and S. mutans ) have an average pairwise protein sequence identity of about 70%. Bacteriophages have been described for many species of Streptococcus . 18 prophages have been described in S. pneumoniae that range in size from 38 to 41 kb in size, encoding from 42 to 66 genes each. Some of the first Streptococcus phages discovered were Dp-1 and ω1 (alias ω-1). In 1981

3900-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

3965-576: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

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4030-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

4095-435: The world's leading pathogens . Additional complications may be caused by GAS, namely acute rheumatic fever and acute glomerulonephritis . Rheumatic fever , a disease that affects the joints , kidneys , and heart valves , is a consequence of untreated strep A infection caused not by the bacterium itself, but due to the antibodies created by the immune system to fight off the infection cross-reacting with other proteins in

4160-462: Was coined in 1877 by Viennese surgeon Albert Theodor Billroth (1829–1894), by combining the prefix "strepto-" (from Ancient Greek : στρεπτός , romanized :  streptós , lit.   'easily twisted, pliant'), together with the suffix "-coccus" (from Modern Latin : coccus , from Ancient Greek: κόκκος , romanized:  kókkos , lit.   'grain, seed, berry'.) In 1984, many bacteria formerly grouped in

4225-445: Was re-examined by Patel and Gupta through the analysis of comprehensive phylogenetic trees constructed based on four different datasets of proteins and the identification of 134 highly specific molecular signatures (in the form of conserved signature indels ) that are exclusively shared by the entire genus or its distinct subclades. The results revealed the presence of two main clades at the highest level within Streptococcus , termed

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