Gemella | |
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Genus: | Gemella Berger 1960 |
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G. asaccharolytic [2] Contents |
Gemella is a genus of Gram-positive bacteria that thrive best at high partial pressure of CO2.
A Gemella species was first described as Neisseria hemolysans in 1938. [3] It was reclassified as a new genus in 1960 when strains were found to be distinct enough from Neisseria to require a new genus. [4] The name was suggested based on the organism being a diplococcus and gemellus is the diminutive of geminus, [5] which is Latin for twin. They are facultatively anaerobic and give negative reactions to both oxidase and catalase tests. They are obligately fermentative, producing either a mixture of acetic and lactic acids or an equimolar molar mixture of acetic acid and CO2. For example, G. haemolysans ferments glucose forming a mixture of acetic and lactic acids in the absence of oxygen, whereas when oxygen is present, it forms acetic acid and CO2. [6]
Gemella bacteria are primarily found in the mucous membranes of humans and other animals, particularly in the oral cavity and upper digestive tract. Gemella haemolysans has been found to be involved in pulmonary exacerbations of cystic fibrosis patients. [7] As of the year 2000 it had been reported in 15 cases of human endocarditis, mainly in men with underlying valvular disease and/or poor dentition or dental manipulation. Most cases were treated with a combination of penicillin and gentamicin with a favorable outcome. [8] Additionally, Gemella asaccharolytica in bacterial vaginosis is associated with increase risk of HIV infection in unprotected sex.
Lactobacillus is a genus of Gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-spore-forming bacteria. Until March 2020, the genus Lactobacillus comprised over 260 phylogenetically, ecologically, and metabolically diverse species; a taxonomic revision of the genus in 2020 assigned lactobacilli to 25 genera.
A coccus is any bacterium or archaeon that has a spherical, ovoid, or generally round shape. Bacteria are categorized based on their shapes into three classes: cocci (spherical-shaped), bacillus (rod-shaped) and spirochetes (spiral-shaped) cells. Coccus refers to the shape of the bacteria, and can contain multiple genera, such as staphylococci or streptococci. Cocci can grow in pairs, chains, or clusters, depending on their orientation and attachment during cell division. Contrast to many bacilli-shaped bacteria, most cocci bacteria do not have flagella and are non-motile.
Colistin, also known as polymyxin E, is an antibiotic medication used as a last-resort treatment for multidrug-resistant Gram negative infections including pneumonia. These may involve bacteria such as Pseudomonas aeruginosa, Klebsiella pneumoniae, or Acinetobacter. It comes in a form which can be injected into a vein or into a muscle, or inhaled, known as colistimethate sodium and one which is applied to the skin or taken by mouth, known as colistin sulfate. Resistance to colistin began to appear as of 2015.
Lactiplantibacillus plantarum is a widespread member of the genus Lactiplantibacillus and commonly found in many fermented food products as well as anaerobic plant matter. L. plantarum was first isolated from saliva, based on its ability to temporarily persist in plants, the insect intestine and in the intestinal tract of vertebrate animals, it was designated as nomadic organism. L. plantarum is Gram positive, bacilli shaped bacterium. L. plantarum cells are rods with rounded ends, straight, generally 0.9–1.2 μm wide and 3–8 μm long, occurring singly, in pairs or in short chains. L. plantarum has one of the largest genomes known among the lactic acid bacteria and is a very flexible and versatile species. It is estimated to grow between pH 3.4 and 8.8. Lactiplantibacillus plantarum can grow in the temperature range 12 °C to 40 °C.
Pseudomonas aeruginosa is a common encapsulated, Gram-negative, facultatively aerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, P. aeruginosa is a multidrug resistant pathogen recognized for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses – hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes.
Moraxella catarrhalis is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system, and joints of humans. It causes the infection of the host cell by sticking to the host cell using trimeric autotransporter adhesins.
Burkholderia cepacia complex (BCC), or simply Burkholderia cepacia, is a group of catalase-producing, lactose-nonfermenting, Gram-negative bacteria composed of at least 20 different species, including B. cepacia, B. multivorans, B. cenocepacia, B. vietnamiensis, B. stabilis, B. ambifaria, B. dolosa, B. anthina, B. pyrrocinia and B. ubonensis. B. cepacia is an opportunistic human pathogen that most often causes pneumonia in immunocompromised individuals with underlying lung disease. Patients with sickle-cell haemoglobinopathies are also at risk. The species complex also attacks young onion and tobacco plants, and displays a remarkable ability to digest oil.
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.
Gemella morbillorum is a species of bacteria within the genus Gemella. It is a facultative anaerobic Gram positive coccus usually preferring capnophilic or microaerophilic environments. From its discovery in 1917 until 1988, it was known as Streptococcus morbillorum. The name change followed closer examination with DNA filter hybridization which found it was very close to the species Gemella haemolysans.
Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical (cocci) bacteria that share common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and milk products, produce lactic acid as the major metabolic end product of carbohydrate fermentation, giving them the common name lactic acid bacteria (LAB).
Alcaligenes is a genus of Gram-negative, aerobic, rod-shaped bacteria. The species are motile with amphitrichous flagella and rarely nonmotile. It is a genus of non-fermenting bacteria. Additionally, some strains of Alcaligenes are capable of anaerobic respiration, but they must be in the presence of nitrate or nitrite; otherwise, their metabolism is respiratory and never fermentative; The genus does not use carbohydrates. Strains of Alcaligenes are found mostly in the intestinal tracts of vertebrates, decaying materials, dairy products, water, and soil; they can be isolated from human respiratory and gastrointestinal tracts and wounds in hospitalized patients with compromised immune systems. They are occasionally the cause of opportunistic infections, including nosocomial sepsis.
The Lactobacillaceae are a family of lactic acid bacteria. It is the only family in the Lactic acid bacteria which includes homofermentative and heterofermentative organisms; in the Lactobacillaceae, the pathway used for hexose fermentation is a genus-specific trait. Lactobacillaceae include the homofermentative lactobacilli Lactobacillus, Holzapfelia, Amylolactobacillus, Bombilactobacillus, Companilactobacillus, Lapidilactobacillus, Agrilactobacillus, Schleiferilactobacillus, Loigolactobacillus, Lacticaseibacillus, Latilactobacillus, Dellaglioa, Liquorilactobacillus, Ligilactobacillus, and Lactiplantibacillus; the heterofermentative lactobacilli Furfurilactobacillus, Paucilactobacillus, Limosilactobacillus, Fructilactobacillus, Acetilactobacillus, Apilactobacillus, Levilactobacillus, Secundilactobacillus, and Lentilactobacillus, which were previously classified in the genus Lactobacillus; and the heterofermentative genera Convivina, Frucctobacillus, Leuconostoc, Oenococcus, and Weissella which were previously classified in the Leuconostocaceae.
Food microbiology is the study of the microorganisms that inhibit, create, or contaminate food. This includes the study of microorganisms causing food spoilage; pathogens that may cause disease ; microbes used to produce fermented foods such as cheese, yogurt, bread, beer, and wine; and microbes with other useful roles, such as producing probiotics.
Levilactobacillus brevis is a gram-positive, rod shaped species of lactic acid bacteria which is heterofermentative, creating CO2, lactic acid and acetic acid or ethanol during fermentation. L. brevis is the type species of the genus Levilactobacillus (previously L. brevis group), which comprises 24 species (http://www.lactobacillus.ualberta.ca/, http://www.lactobacillus.uantwerpen.be/). It can be found in many different environments, such as fermented foods, and as normal microbiota. L.brevis is found in food such as sauerkraut and pickles. It is also one of the most common causes of beer spoilage. Ingestion has been shown to improve human immune function, and it has been patented several times. Normal gut microbiota L.brevis is found in human intestines, vagina, and feces.
SCOBY is the commonly used acronym for "symbiotic culture of bacteria and yeast", and is formed after the completion of a unique fermentation process of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast to form several sour foods and beverages such as kombucha and kimchi. Beer and wine also undergo fermentation with yeast, but the lactic acid bacteria and acetic acid bacteria components unique to SCOBY are usually viewed as a source of spoilage rather than a desired addition. Both LAB and AAB enter on the surface of barley and malt in beer fermentation and grapes in wine fermentation; LAB lower the pH of the beer while AAB take the ethanol produced from the yeast and oxidize it further into vinegar, resulting in a sour taste and smell. AAB are also responsible for the formation of the cellulose SCOBY.
Lentilactobacillus buchneri is a gram-positive, non-spore forming, anaerobic, rod prokaryote. L. buchneri is a heterofermentative bacteria that produces lactic acid and acetic acid during fermentation. It is used as a bacterial inoculant to improve the aerobic stability of silage. These bacteria are inoculated and used for preventing heating and spoilage after exposure to air.
Veillonella are Gram-negative bacteria anaerobic cocci, unlike most Firmicutes, which are Gram-positive bacteria. This bacterium is well known for its lactate fermenting abilities. It is a normal bacterium in the intestines and oral mucosa of mammals. In humans they have been implicated in cases of osteomyelitis and endocarditis, for example with the species Veillonella parvula.
Streptococcus constellatus is a species of Streptococcus part of the normal flora in the oral cavity, urogenital region, and intestinal tract. However, it can frequently cause purulent infections in other parts of the body. DNA homology studies and 16S rRNA sequence analysis demonstrate S. constellatus belongs to the Streptococcus anginosus group along with Streptococcus intermedius and Streptococcus anginosus.
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. S. equinus is seldom found in humans. Equivalence with Streptococcus bovis has been contested.
In 1928, Neisseria flavescens was first isolated from cerebrospinal fluid in the midst of an epidemic meningitis outbreak in Chicago. These gram-negative, aerobic bacteria reside in the mucosal membranes of the upper respiratory tract, functioning as commensals. However, this species can also play a pathogenic role in immunocompromised and diabetic individuals. In rare cases, it has been linked to meningitis, pneumonia, empyema, endocarditis, and sepsis.