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Polymixins
Polymyxins are antibiotics. Polymyxins B and E (also known as colistin) are used in the treatment of Gram-negative bacterial infections. They work mostly by breaking up the bacterial cell membrane. They are part of a broader class of molecules called nonribosomal peptides. They are produced in nature by Gram-positive bacteria such as ''Paenibacillus polymyxa''. Medical use Polymyxin antibiotics are relatively neurotoxic and nephrotoxic, so are usually used only as a last resort if modern antibiotics are ineffective or are contraindicated. Typical uses are for infections caused by strains of multiple drug-resistant ''Pseudomonas aeruginosa'' or carbapenemase-producing Enterobacteriaceae. Polymyxins have less effect on Gram-positive organisms, and are sometimes combined with other agents (as with trimethoprim/polymyxin) to broaden the effective spectrum. Polymyxins B are not absorbed from the gastrointestinal tract, so they are only administered orally if the goal is to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colistin
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 two forms: colistimethate sodium can be injected into a vein, injected into a muscle, or inhaled, and colistin sulfate is mainly applied to the skin or taken by mouth. Colistimethate sodium is a prodrug; it is produced by the reaction of colistin with formaldehyde and sodium bisulfite, which leads to the addition of a sulfomethyl group to the primary amines of colistin. Colistimethate sodium is less toxic than colistin when administered parenterally. In aqueous solutions, it undergoes hydrolysis to form a complex mixture of partially sulfomethylated derivatives, as well as colistin. Resistance to colistin began to appear as of 2015. Common side effects of the injectable form include kidne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Route Of Administration
In pharmacology and toxicology, a route of administration is the way by which a medication, drug, fluid, poison, or other substance is taken into the body. Routes of administration are generally classified by the location at which the substance is applied. Common examples include oral administration, oral and intravenous therapy, intravenous administration. Routes can also be classified based on where the target of action is. Action may be topical medication, topical (local), enteral administration, enteral (system-wide effect, but delivered through the gastrointestinal tract), or #Parenteral, parenteral (systemic action, but is delivered by routes other than the GI tract). Route of administration and dosage form are aspects of drug delivery. Classification Routes of administration are usually classified by application location (or exposition). The route or course the active substance takes from application location to the location where it has its target effect is usually rat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimicrobial Resistance
Antimicrobial resistance (AMR or AR) occurs when microbes evolve mechanisms that protect them from antimicrobials, which are drugs used to treat infections. This resistance affects all classes of microbes, including bacteria (antibiotic resistance), viruses (antiviral resistance), Parasitic disease, parasites (antiparasitic resistance), and fungi (antifungal resistance). Together, these adaptations fall under the AMR umbrella, posing significant challenges to healthcare worldwide. Misuse and improper management of antimicrobials are primary drivers of this resistance, though it can also occur naturally through genetic mutations and the spread of resistant genes. Antibiotic resistance, a significant AMR subset, enables bacteria to survive antibiotic treatment, complicating infection management and treatment options. Resistance arises through spontaneous mutation, horizontal gene transfer, and increased selective pressure from Antibiotic misuse, antibiotic overuse, both in medicin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosynthesis Of Polymyxin D
Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme- catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrates, with conversion by the living organism either into simpler or more complex products. Examples of biosynthetic pathways include those for the production of amino acids, lipid membrane components, and nucleotides, but also for the production of all classes of biological macromolecules, and of acetyl-coenzyme A, adenosine triphosphate, nicotinamide adenine dinucleotide and other key intermediate and transactional molecules needed for metabolism. Thus, in biosynthesis, any of an array of compounds, from simple to complex, are converted into other compounds, and so it includes both the catabolism and anabolism (building up and breaking down) of complex molecules (including macromolecules). Biosynthetic processes are ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-terminus
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amine group is bonded to the carboxylic group of another amino acid, making it a chain. That leaves a free carboxylic group at one end of the peptide, called the C-terminus, and a free amine group on the other end called the N-terminus. By convention, peptide sequences are written N-terminus to C-terminus, left to right (in LTR writing systems). This correlates the translation direction to the text direction, because when a protein is translated from messenger RNA, it is created from the N-terminus to the C-terminus, as amino acids are added to the carboxyl end of the protein. Chemistry Each amino acid has an amine group and a carboxylic group. Amino acids link to one another by peptide bonds which form through a dehydration reaction that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
α,γ-diaminobutyric Acid
2,4-Diaminobutyric acid, also known as DABA, is GABA-T non-competitive inhibitor and a GABA reuptake inhibitor. Mechanism of action DABA's main action is being an inhibitor of GABA transaminase, an enzyme that converts GABA back to glutamate. When the enzyme is inhibited, this conversion cannot happen, therefore, GABA levels are elevated. It has also been observed that 2,4-diaminobutyric acid is a GABA reuptake inhibitor. This action further elevates levels of GABA. Toxicity In addition to being a neurotoxin, DABA can also cause liver damage. Its potential as an anticonvulsant is unclear, it has been shown to have anticonvulsant properties against picrotoxin Picrotoxin, also known as cocculin, is a poisonous crystalline plant compound. It was first isolated by the French pharmacist and chemist Pierre François Guillaume Boullay (1777–1869) in 1812. The name "picrotoxin" is a combination of the Gree ..., but over the long term, it could paradoxically cause convulsions. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life. Amino acids can be classified according to the locations of the core structural functional groups ( alpha- , beta- , gamma- amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type ( aliphatic, acyclic, aromatic, polar, etc.). In the form of proteins, amino-acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life on Earth and its emergence. Amino acids are formally named by the IUPAC- IUBMB Joint Commi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paenibacillus
''Paenibacillus'' is a genus of facultative anaerobic, endospore-forming bacteria, originally included within the genus ''Bacillus'', and then reclassified as a separate genus in 1993.Ash C, Priest FG, Collins MD: Molecular identification of rRNA group 3 bacilli (Ash, Farrow, Wallbanks and Collins) using a PCR probe test. Proposal for the creation of a new genus Paenibacillus. Antonie van Leeuwenhoek 1993, 64:253-260. Bacteria belonging to this genus have been detected in a variety of environments, such as soil, water, rhizosphere, vegetable matter, forage, and insect larvae, as well as clinical samples. The name reflects: Latin ''paene'' means almost, so the paenibacilli are literally "almost bacilli". The genus includes '' P. larvae'', which causes American foulbrood in honeybees, '' P. polymyxa'', which is capable of fixing nitrogen, so is used in agriculture and horticulture, the ''Paenibacillus'' sp. JDR-2 which is a rich source of chemical agents for biotechnology applicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymyxin Structure Schematic
Polymyxins are antibiotics. Polymyxins B and E (also known as colistin) are used in the treatment of Gram-negative bacterial infections. They work mostly by breaking up the bacterial cell membrane. They are part of a broader class of molecules called nonribosomal peptides. They are produced in nature by Gram-positive bacteria such as ''Paenibacillus polymyxa''. Medical use Polymyxin antibiotics are relatively neurotoxic and nephrotoxic, so are usually used only as a last resort if modern antibiotics are ineffective or are contraindicated. Typical uses are for infections caused by strains of multiple drug-resistant ''Pseudomonas aeruginosa'' or carbapenemase-producing Enterobacteriaceae. Polymyxins have less effect on Gram-positive organisms, and are sometimes combined with other agents (as with trimethoprim/polymyxin) to broaden the effective spectrum. Polymyxins B are not absorbed from the gastrointestinal tract, so they are only administered orally if the goal is to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mcr-1
The mobilized colistin resistance (''mcr'') gene confers plasmid-mediated resistance to colistin, one of a number of last-resort antibiotics for treating Gram-negative infections. ''mcr-1'', the original variant, is capable of horizontal transfer between different strains of a bacterial species. After discovery in November 2015 in ''E. coli'' (strain SHP45) from a pig in China it has been found in ''Escherichia coli'', ''Salmonella enterica'', ''Klebsiella pneumoniae'', '' Enterobacter aerogenes'', and ''Enterobacter cloacae''. , it has been detected in more than 30 countries on 5 continents in less than a year. Description The "mobilized colistin resistance" (''mcr-1'') gene confers plasmid-mediated resistance to colistin, a polymyxin and one of a number of last-resort antibiotics for treating infections. The gene is found in no less than ten species of the Enterobacteriaceae: ''Escherichia coli'', ''Salmonella'', ''Klebsiella pneumoniae'', '' Enterobacter aerogenes'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimicrobial Resistance
Antimicrobial resistance (AMR or AR) occurs when microbes evolve mechanisms that protect them from antimicrobials, which are drugs used to treat infections. This resistance affects all classes of microbes, including bacteria (antibiotic resistance), viruses (antiviral resistance), Parasitic disease, parasites (antiparasitic resistance), and fungi (antifungal resistance). Together, these adaptations fall under the AMR umbrella, posing significant challenges to healthcare worldwide. Misuse and improper management of antimicrobials are primary drivers of this resistance, though it can also occur naturally through genetic mutations and the spread of resistant genes. Antibiotic resistance, a significant AMR subset, enables bacteria to survive antibiotic treatment, complicating infection management and treatment options. Resistance arises through spontaneous mutation, horizontal gene transfer, and increased selective pressure from Antibiotic misuse, antibiotic overuse, both in medicin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detergent
A detergent is a surfactant or a mixture of surfactants with Cleanliness, cleansing properties when in Concentration, dilute Solution (chemistry), solutions. There are a large variety of detergents. A common family is the alkylbenzene sulfonates, which are soap-like compounds that are more soluble than soap in hard water, because the polar sulfonate is less likely than the polar carboxylate of soap to bind to calcium and other ions found in hard water. Definitions The word ''detergent'' is derived from the Latin adjective , from the verb , meaning to wipe or polish off. Detergent can be defined as a surfactant or a mixture of surfactants with cleansing properties when in Concentration, dilute Solution (chemistry), solutions. However, conventionally, detergent is used to mean synthetic cleaning compounds as opposed to ''soap'' (a salt of the natural fatty acid), even though soap is also a detergent in the true sense. In domestic contexts, the term ''detergent'' refers to househ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
