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Francisellaceae
''Francisella'' is a genus of Gram-negative bacteria. They are small coccobacillary or rod-shaped, nonmotile organisms, which are also facultative intracellular parasites of macrophages. Strict aerobes, ''Francisella'' colonies bear a morphological resemblance to those of the genus ''Brucella''. Some ''Francisella'' species are pathogenic bacteria but some others are endosymbionts of ticks. Ticks do not use any other food source than vertebrate blood and therefore ingest high levels of protein, iron and salt, but few vitamins. To overcome these nutritional deficiencies, ticks have evolved obligate interactions with nutritional endosymbionts, including ''Francisella'' endosymbionts. Their experimental elimination typically results in decreased tick survival, molting, fecundity and egg viability, as well as in physical abnormalities, which all are fully restored with an oral supplement of B vitamins. The genome sequencing of ''Francisella'' endosymbionts confirmed that they consist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francisella Novicida
''Francisella novicida'' is a bacterium of the Francisellaceae family, which consist of Gram-negative pathogenic bacteria. These bacteria vary from small Coccus, cocci to rod-shaped, and are most known for their intracellular parasitic capabilities. In this family, six species have been identified; however, the species ''F. novicida'' is under intense scrutiny. Though some believe it should be classified with its own species designation, others argue it should be reclassified as a subspecies under ''F. tularensis''. If it were to be classified as a subspecies, ''F. novicida'' would join the other known subspecies including ''F. t. tularensis'' (type A) and ''F. t. holarctica'' (type B). Biochemical assays for identifying ''F. tularensis'' subtypes and strains are not ideal because the results are often non-definitive and subject to variation, therefore these assays should only be considered as supplementary tests for identification of ''Francisella'' species and subspecies. Several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francisella Piscicida
''Francisella piscicida'' is a bacterium present in Atlantic cod The Atlantic cod (: cod; ''Gadus morhua'') is a fish of the family Gadidae, widely consumed by humans. It is also commercially known as '' cod'' or ''codling''. It is the causative agent of francisellosis, a serious disease present in Norwegian cod farming. References Thiotrichales Bacteria described in 2008 {{gammaproteobacteria-stub ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francisella Tularensis
''Francisella tularensis'' is a pathogenic species of Gram-negative coccobacillus, an aerobic bacterium. It is nonspore-forming, nonmotile, and the causative agent of tularemia, the pneumonic form of which is often lethal without treatment. It is a fastidious, facultative intracellular bacterium, which requires cysteine for growth. Due to its low infectious dose, ease of spread by aerosol, and high virulence, ''F. tularensis'' is classified as a Tier 1 Select Agent by the U.S. government, along with other potential agents of bioterrorism such as ''Yersinia pestis, Bacillus anthracis'', and Ebola virus. When found in nature, ''Francisella tularensis'' can survive for several weeks at low temperatures in animal carcasses, soil, and water. In the laboratory, ''F. tularensis'' appears as small rods (0.2 by 0.2 μm), and is grown best at 35–37 °C. History This species was discovered in ground squirrels in Tulare County, California in 1911. ''Bacterium tularense'' was so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RRNA
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal DNA (rDNA) and then bound to ribosomal proteins to form SSU rRNA, small and LSU rRNA, large ribosome subunits. rRNA is the physical and mechanical factor of the ribosome that forces transfer RNA (tRNA) and messenger RNA (mRNA) to process and Translation (biology), translate the latter into proteins. Ribosomal RNA is the predominant form of RNA found in most cells; it makes up about 80% of cellular RNA despite never being translated into proteins itself. Ribosomes are composed of approximately 60% rRNA and 40% ribosomal proteins, though this ratio differs between Prokaryote, prokaryotes and Eukaryote, eukaryotes. Structure Although the primary structure of rRNA sequences can vary across organisms, Base pair, base-pairing within these sequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
16S Ribosomal RNA
16S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The genes coding for it are referred to as 16S rRNA genes and are used in reconstructing phylogenies, due to the slow rates of evolution of this region of the gene. Carl Woese and George E. Fox were two of the people who pioneered the use of 16S rRNA in phylogenetics in 1977. Multiple sequences of the 16S rRNA gene can exist within a single bacterium. Terminology The descriptor ''16S'' refers to the size of these ribosomal subunits as reflected indirectly by the speed at which they sediment when samples are centrifuged. Thus ''16S'' means 16 Svedburg units. Functions * Like the large (23S) ribosomal RNA, it has a structural role, acting as a scaffold defining the positions of the ribosomal proteins. * The 3-end contains the anti- Shine-Dalgarno sequence, which binds upstream ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sepsis
Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and symptoms include fever, tachycardia, increased heart rate, hyperventilation, increased breathing rate, and mental confusion, confusion. There may also be symptoms related to a specific infection, such as a cough with pneumonia, or dysuria, painful urination with a pyelonephritis, kidney infection. The very young, old, and people with a immunodeficiency, weakened immune system may not have any symptoms specific to their infection, and their hypothermia, body temperature may be low or normal instead of constituting a fever. Severe sepsis may cause organ dysfunction and significantly reduced blood flow. The presence of Hypotension, low blood pressure, high blood Lactic acid, lactate, or Oliguria, low urine output may suggest poor blood flow. Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tularemia
Tularemia, also known as rabbit fever, is an infectious disease caused by the bacterium '' Francisella tularensis''. Symptoms may include fever, skin ulcers, and enlarged lymph nodes. Occasionally, a form that results in pneumonia or a throat infection may occur. The bacterium is typically spread by ticks, deer flies, or contact with infected animals. It may also be spread by drinking contaminated water or breathing in contaminated dust. It does not spread directly between people. Diagnosis is by blood tests or cultures of the infected site. Prevention includes the use of insect repellent and long pants, rapidly removing ticks, and not disturbing dead animals. Treatment is typically with the antibiotic streptomycin. Gentamicin, doxycycline, or ciprofloxacin may also be used. Between the 1970s and 2015, around 200 cases were reported in the United States a year. Males are affected more often than females. It occurs most frequently in the young and the middle aged. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Francis (bacteriologist)
Edward Francis may refer to: * Edward Howel Francis (1924–2014), geologist *Edward Francis, bacteriologist involved in the discovery of '' Francisella'' * Edward Francis (MP), MP for Steyning Steyning ( ) is a town and civil parishes in England, civil parish in the Horsham District, Horsham district of West Sussex, England. It is located at the north end of the River Adur gap in the South Downs, north of the coastal town of Shoreha ... * Ed Francis (1926–2016), wrestler * Eddie Francis (born 1974), Canadian politician * Edward Francis (bishop) (1930–2017), Bishop of Sivagangai 1987–2005 * Edward Francis (priest) (1929–2004), Archdeacon of Bromley * Edward Carey Francis (1897–1966), mathematician and Kenyan educator * Edward Francis (footballer) (born 1999), English footballer See also * * * Francis (surname) {{hndis, Francis, Edward ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbiology
Microbiology () is the branches of science, scientific study of microorganisms, those being of unicellular organism, unicellular (single-celled), multicellular organism, multicellular (consisting of complex cells), or non-cellular life, acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, bacteriology, protistology, mycology, immunology, and parasitology. The organisms that constitute the microbial world are characterized as either prokaryotes or eukaryotes; eukaryote, Eukaryotic microorganisms possess membrane-bound organelles and include fungi and protists, whereas prokaryote, prokaryotic organisms are conventionally classified as lacking membrane-bound organelles and include Bacteria and Archaea. Microbiologists traditionally relied on culture, staining, and microscopy for the isolation and identification of microorganisms. However, less than 1% of the microorganisms present in common environments can be cultured in isolation using c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folate
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and storage. Folate is required for the body to make DNA and RNA and metabolise amino acids necessary for cell division and maturation of blood cells. As the human body cannot make folate, it is required in the diet, making it an essential nutrient. It occurs naturally in many foods. The recommended adult daily intake of folate in the U.S. is 400 micrograms from foods or dietary supplements. Folate in the form of folic acid is used to treat anemia caused by folate deficiency. Folic acid is also used as a supplement by women during pregnancy to reduce the risk of neural tube defects (NTDs) in the baby. NTDs include anencephaly and spina bifida, among other defects. Low levels in early pregnancy are believed to be the cause of more tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riboflavin
Riboflavin, also known as vitamin B2, is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in energy metabolism, cellular respiration, and antibody production, as well as normal growth and development. The coenzymes are also required for the metabolism of Niacin (nutrient), niacin, vitamin B6, vitamin B6, and folate. Riboflavin is prescription drug, prescribed to treat Corneal ectatic disorders, corneal thinning, and taken orally, may reduce the incidence of migraine headaches in adults. Riboflavin deficiency is rare and is usually accompanied by deficiencies of other vitamins and nutrients. It may be prevented or treated by oral supplements or by injections. As a water-soluble vitamin, any riboflavin consumed in excess of nutritional requirements is not stored; it is either not absorbed or is absorbed and quickly clearance (pharma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotin
Biotin (also known as vitamin B7 or vitamin H) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', borrowed from the German , derives from the Ancient Greek word (; 'life') and the suffix "-in" (a suffix used in chemistry usually to indicate 'forming'). Biotin appears as a white, needle-like crystalline solid. Chemical description Biotin is classified as a heterocyclic compound, with a sulfur-containing tetrahydrothiophene ring fused to a ureido group. A C5-carboxylic acid side chain is appended to the former ring. The ureido ring, containing the −N−CO−N− group, serves as the carbon dioxide carrier in carboxylation reactions. Biotin is a coenzyme for five carboxylase enzymes, which are involved in the catabolism of amino acids and fatty acids, synthesis of fatty acids, and gluconeogenesis. Biotinylat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
