Streptococcus is a genus of gram-positive coccus or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales, 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.
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).
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 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.
Lactobacillus bulgaricus is one of over 200 published species in the Lactobacillus genome complex (LGC) and is the main bacterium used for the production of yogurt. It also plays a crucial role in the ripening of some cheeses, as well as in other processes involving naturally fermented products. It is defined as homofermentive lactic acid bacteria due to lactic acid being the single end product of its carbohydrate digestion. It is also considered a probiotic.
Streptococcus agalactiae is a gram-positive coccus with a tendency to form chains. It is a beta-hemolytic, catalase-negative, and facultative anaerobe.
Peptostreptococcus is a genus of anaerobic, Gram-positive, non-spore forming bacteria. The cells are small, spherical, and can occur in short chains, in pairs or individually. They typically move using cilia. Peptostreptococcus are slow-growing bacteria with increasing resistance to antimicrobial drugs. Peptostreptococcus is a normal inhabitant of the healthy lower reproductive tract of women.
Streptococcus bovis is a species of Gram-positive bacteria that in humans is associated with urinary tract infections, endocarditis, sepsis, and colorectal cancer. S. gallolyticus is commonly found in the alimentary tract of cattle, sheep, and other ruminants, and may cause ruminal acidosis or feedlot bloat. It is also associated with spontaneous bacterial peritonitis, a frequent complication occurring in patients affected by cirrhosis. Equivalence with Streptococcus equinus has been contested.
Rebecca Craighill Lancefield was a prominent American microbiologist. She joined the Rockefeller Institute for Medical Research in New York in 1918, and was associated with that institute throughout her long and outstanding career. Her bibliography comprises more than 50 publications published over 60 years.
Globosides are a sub-class of the lipid class glycosphingolipid with three to nine sugar molecules as the side chain of ceramide. The sugars are usually a combination of N-acetylgalactosamine, D-glucose or D-galactose. One characteristic of globosides is that the "core" sugars consists of Glucose-Galactose-Galactose (Ceramide-βGlc4-1βGal4-1αGal), like in the case of the most basic globoside, globotriaosylceramide (Gb3), also known as pk-antigen. Another important characteristic of globosides is that they are neutral at pH 7, because they usually do not contain neuraminic acid, a sugar with an acidic carboxy-group. However, some globosides with the core structure Cer-Glc-Gal-Gal do contain neuraminic acid, e.g. the globo-series glycosphingolipid "SSEA-4-antigen".
Mycobacterium brumae is a rapidly growing environmental mycobacterial species identified in 1993. Aside from one 2004 report of a catheter related bloodstream infection no other infections by this organism have been reported. It was first isolated from water, soil and one human sputum sample in Spain.
Arcanobacterium haemolyticum is a species of bacteria classified as a gram-positive bacillus. It is catalase-negative, facultative anaerobic, beta-hemolytic, and not motile. It has been known to cause head and neck infections, pharyngitis, and sinusitis.
Delafloxacin sold under the brand name Baxdela among others, is a fluoroquinolone antibiotic used to treat acute bacterial skin and skin structure infections.
Streptococcus intermedius is an aerotolerant anaerobic commensal bacterium and a member of the Streptococcus anginosus group. The S. anginosus group, occasionally termed “Streptococcus milleri group” (SMG) display hemolytic and serologic diversity, yet share core physiological traits. Though the three members of the SMG are phenotypically diverse, one common trait they share is the mechanism of producing the metabolite diacetyl, which contributes to generating a signature caramel odor. Despite being commensal organisms, members of the S. anginosus group display wide pathogenic potential. S. intermedius has been isolated from patients with periodontitis and fatal purulent infections, especially brain and liver abscesses.
Streptococcus anginosus is a species of Streptococcus. 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.
The Streptococcus anginosus group (SAG), also known as the anginosus group streptococci (AGS) or the milleri group streptococci (MGS), are a group of several species of streptococci with clinical similarities. The group is named after a principal member species, Streptococcus anginosus. The older name Streptococcus milleri is now pseudotaxonomic, as the idea that these streptococci constituted a single species was incorrect. The anginosus group streptococci are members of the viridans streptococci group. They have been implicated as etiologic agents in a variety of serious purulent infections, but because of their heterogeneous characteristics, these organisms may be unrecognized or misidentified by clinical laboratorians. The unique characteristic of them from other pathogenic streptococci, such as S. pyogenes and S. agalactiae, is their ability to cause abscesses.
Streptococcus equinus is a Gram-positive, nonhemolytic, nonpathogenic, lactic acid bacterium of the genus Streptococcus. It is the principal Streptococcus found in the alimentary canal of a horse, and makes up the majority of the bacterial flora in horse feces. Equivalence with Streptococcus bovis has been contested.
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 have been most frequently reported.
Tedizolid, is an oxazolidinone-class antibiotic. Tedizolid phosphate is a phosphate ester prodrug of the active compound tedizolid. It was developed by Cubist Pharmaceuticals, following acquisition of Trius Therapeutics, and is marketed for the treatment of acute bacterial skin and skin structure infections.
Arthrobacter bussei is a pink-coloured, aerobic, coccus-shaped, Gram-stain-positive, oxidase-positive and catalase-positive bacterium isolated from cheese made of cow´s milk. A. bussei is non-motile and does not form spores. Rod–coccus life cycle is not observed. Cells are 1.1–1.5 µm in diameter. On trypticase soy agar it forms pink-coloured, raised and round colonies, which are 1.0 mm in diameter after 5 days at 30 °C The genome of the strain A. bussei KR32T has been fully sequenced.
Photobacterium damselae subsp. damselae is a halophilic gram-negative rod-shaped bacterium. Commonly found in marine environments, P.d. subsp. damselae can cause disease in many species marine wildlife and is an emerging threat in aquaculture. In humans Photobacterium damselae subsp. damselae can cause severe infections.The type strain of Photobacterium damselae subsp damselae is ATCC 33539T.
