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Lancefield Grouping
Lancefield grouping is a system of classification that classifies catalase-negative Gram-positive cocci based on the carbohydrate composition of bacterial antigens found on their cell walls. The system, created by Rebecca Lancefield, was historically used to organize the various members of the family Streptococcaceae, which includes the genera ''Lactococcus'' and ''Streptococcus'', but now is largely superfluous due to explosive growth in the number of streptococcal species identified since the 1970s. However, it has retained some clinical usefulness even after the taxonomic changes, and as of 2018, Lancefield designations are still often used to communicate medical microbiological test results. Enterococcus, formerly known as Group D Streptococcus, were classified as members of the genus Streptococcus until 1984 and were included in the original Lancefield grouping. Many - but not all - species of streptococcus are beta-hemolytic. Notably, Enterococci and ''Streptococcus bovis' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcal Grouping Kit
''Streptococcus'' is a genus of gram-positive bacteria, 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 coordinate system, axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from Staphylococcus, staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cell (biology), cells. Most streptococci are Oxidase test, oxidase-negative and Catalase#Clinical significance and application, catalase-negative, and many are facultative anaerobic organism, facultative anaerobes (capable of growth both aerobically and anaerobically). The term was coined in 1877 by Viennese surgeon Theodor Billroth, Albert Theodor Billroth (1829–1894), by combining the prefix "strepto-" (from ), together with the suffix "-coccus" (from Mode ... [...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 microbiot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Suis
''Streptococcus suis'' is a peanut-shaped, Gram-positive bacterium, and an important pathogen of pigs. Endemic in nearly all countries with an extensive pig industry, ''S. suis'' is also a zoonotic disease, capable of transmission to humans from pigs. Humans can be infected with ''S. suis'' when they handle infected pig carcasses or meat, especially with exposed cuts and abrasions on their hands. Human infection can be severe, with meningitis, septicaemia, endocarditis, and deafness as possible outcomes of infection. Fatal cases of ''S. suis'' are uncommon, but not unknown. Penicillin is the most common antibiotic used in treatment of ''S. suis'' infection; in cases with cardiac involvement (endocarditis), gentamicin should also be given for synergistic effect. Epidemiology and transmission The natural habitat of ''S. suis'' in pigs is the upper respiratory tract, particularly the tonsils and nasal cavity, and the alimentary and genital tracts. An individual pig can carry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactococcus Lactis
''Lactococcus lactis'' is a Gram-positive bacterium used extensively in the production of buttermilk and cheese, but has also become famous as the first genetically modified organism to be used alive for the treatment of human disease. ''L. lactis'' cells are cocci that group in pairs and short chains, and, depending on growth conditions, appear ovoid with a typical length of 0.5 - 1.5 µm. ''L. lactis'' does not produce spores ( nonsporulating) and are not motile ( nonmotile). They have a homofermentative metabolism, meaning they produce lactic acid from sugars. They've also been reported to produce exclusive L-(+)-lactic acid. However, reported D-(−)-lactic acid can be produced when cultured at low pH. The capability to produce lactic acid is one of the reasons why ''L. lactis'' is one of the most important microorganisms in the dairy industry. Based on its history in food fermentation, ''L. lactis'' has generally recognized as safe (GRAS) status, with few case reports ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Mitis
''Streptococcus mitis'' is a mesophilic alpha-hemolytic species of ''Streptococcus'' that inhabits the oral cavity. It is coccus (spherical shaped), gram-positive, catalase negative, and facultative anaerobe. It was previously classified as ''Streptococcus mitior''. Streptococcus mitis is known to cause several medical conditions one of them being infective endocarditis. Classification Members of the Streptococcus genera belong to lactic acid bacteria defined by the formation of lactic acid as an end-product of carbohydrate metabolism. The family ''Streptococcaceae'' is characterized by based upon its 16S rRNA gene sequence analysis within the low (< 50 mol%) G+C branch. There are over 50 species in the genus which are classified by their 16S rRNA sequences. Habitat ''Streptococcus mitis'' primarily resides in the oral cavity which includes the mouth, nasopharynx, and throat. However, there have also been cases of it in the female genital ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Salivarius
''Streptococcus salivarius'' is a species of spherical, gram-positive, facultative anaerobic lactic acid bacteria that is both catalase and oxidase negative. ''S. salivarius'' colonizes (usually in chains) the oral cavity and upper respiratory tract of humans just a few hours after birth, making further exposure to the bacteria harmless in most circumstances. The bacteria is considered an opportunistic pathogen, rarely finding its way into the bloodstream, where it has been implicated in cases of sepsis in people with neutropenia, (a deficiency in white blood cells). ''S. salivarius'' has distinct characteristics when exposed to different environmental nutrients. For example, in the laboratory, if a growth medium is used that includes sucrose then ''S. salivarius'' is able to use the sucrose to produce a capsule around itself. However, if sucrose is replaced by glucose as on a GYC (glucose, yeast extract, calcium carbonate) plate, ''S. salivarius'' is unable to make a caps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Sanguis
''Streptococcus sanguinis'', formerly known as ''Streptococcus sanguis'', is a Gram-positive facultative anaerobic coccus species of bacteria and a member of the Viridans Streptococcus group. ''S. sanguinis'' is a normal inhabitant of the healthy human mouth where it is particularly found in dental plaque, where it modifies the environment to make it less hospitable for other strains of Streptococcus that cause cavities, such as ''Streptococcus mutans''. Pathogenicity ''S. sanguinis'' may gain entrance to the bloodstream when opportunity presents (dental cleanings and surgeries) and colonize the heart valves, particularly the mitral and aortic valves, where it is the most common cause of subacute bacterial endocarditis. For this reason, oral surgeons often prescribe a short course of antibiotics to be taken a few days before to a few days after oral surgery. Once an infection has occurred, treatment is much more complicated and generally involves the administration of several w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Anginosus
''Streptococcus anginosus'' is a species of ''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 ...''. This species, '' Streptococcus intermedius'', and '' Streptococcus constellatus'' constitute the ''anginosus'' group, which is sometimes also referred to as the ''milleri'' group after the previously assumed but later refuted idea of a single species ''Streptococcus milleri''. Phylogenetic relatedness of ''S. anginosus, S. constellatus, and S. intermedius'' has been confirmed by rRNA sequence analysis. General characteristics The majority of ''Streptococcus anginosus'' strains produce acetoin from glucose, ferment lactose, trehalose, salicin, and sucrose, and hydrolyze esculin and arginine. Carbon dioxide can stimulate growth or is even required for growth in certain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterococcus Durans
''Enterococcus durans'' is a species of ''Enterococcus''. It is a gram-positive, catalase- and oxidase-negative, coccus bacterium. The organism is also a facultative anaerobic organism. Prior to 1984, it was known as ''Streptococcus durans''. Certain strains have also been identified as producers of anti-inflammatory Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs remedy pain by reducing inflammation as o ... agents, which are being studied in medical research.Carasi, P., Racedo, S. M., Jacquot, C., Elie, A. M., Serradell, M. de los Á., & Urdaci, M. C. (2017). Enterococcus durans EP1 a Promising Anti-inflammatory Probiotic Able to Stimulate sIgA and to Increase Faecalibacterium prausnitzii Abundance. Frontiers in Immunology, 8, 88. http://doi.org/10.3389/fimmu.2017.00088 References Further reading * External links Ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterococcus Faecium
''Enterococcus faecium'' is a Gram-positive, gamma-hemolytic or non- hemolytic bacterium in the genus ''Enterococcus''. It can be commensal (innocuous, coexisting organism) in the gastrointestinal tract of humans and animals, but it may also be pathogenic, causing diseases such as neonatal meningitis or endocarditis. Vancomycin-resistant ''E. faecium'' is often referred to as VRE. Pathogenic properties This bacterium has developed multi-drug antibiotic resistance and uses colonization and secreted factors in virulence (enzymes capable of breaking down fibrin, protein and carbohydrates to regulate adherence bacteria to inhibit competitive bacteria). The enterococcal surface protein (Esp) allows the bacteria to aggregate and form biofilms. Additional virulence factors include aggregation substance (AS), cytosolin, and gelantinase. AS allows the microbe to bind to target cells and it facilitates the transfer of genetic material between cells. By producing the enterocins A, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterococcus Faecalis
''Enterococcus faecalis'' – formerly classified as part of the group D ''Streptococcus'' system – is a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans. Like other species in the genus ''Enterococcus'', ''E. faecalis'' is found in healthy humans and can be used as a probiotic. The probiotic strains such as Symbioflor1 and EF-2001 are characterized by the lack of specific genes related to drug resistance and pathogenesis. As an opportunistic pathogen, ''E. faecalis'' can cause life-threatening infections, especially in the nosocomial (hospital) environment, where the naturally high levels of antibiotic resistance found in ''E. faecalis'' contribute to its pathogenicity. ''E. faecalis'' has been frequently found in reinfected, root canal-treated teeth in prevalence values ranging from 30% to 90% of the cases. Re-infected root canal-treated teeth are about nine times more likely to harbor ''E. faecalis'' than cases of primary infections. Physi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Dysgalactiae
''Streptococcus dysgalactiae'' is a gram positive, beta-haemolytic, coccal bacterium belonging to the family ''Streptococcaceae''. It is capable of infecting both humans and animals, but is most frequently encountered as a commensal of the alimentary tract, genital tract, or less commonly, as a part of the skin flora. The clinical manifestations in human disease range from superficial skin-infections and tonsillitis, to severe necrotising fasciitis and bacteraemia. The incidence of invasive disease has been reported to be rising. Several different animal species are susceptible to infection by ''S. dysgalactiae'', but bovine mastitis and infectious arthritis in lambs (joint ill) have been most frequently reported. ''Streptococcus dysgalactiae'' is currently divided into the subspecies '' Streptococcus dysgalactiae subspecies equisimilis'' and '' Streptococcus dysgalactiae subspecies dysgalactiae''; the former mostly associated with human disease, and the latter almost exclusi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
