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Lugdunin
Lugdunin is an investigational antibiotic, classified as a thiazolidine-containing cyclic peptide. It was isolated in 2016 after ''Staphylococcus lugdunensis'' was identified as the species of bacteria from the human nose that suppressed growth of species of disease-causing bacteria in that part of the human microbiome. Lugdunin is a non-ribosomally synthesized cyclic peptide that inhibits growth of ''Staphylococcus aureus'' strains. The lugdunin genes are located on a 30-kbp operon. The genes ''lugA'', ''lugB'', ''lugC'', and ''lugD'' encode four non-ribosomal peptide synthases, which are preceded by a putative regulator gene ''lugR''. Biosynthesis Lugdunin is synthesized by non ribosomal peptide synthetases in ''S. lugdunensis''. The molecule is a cyclic peptide composed of a thiazolidine heterocycle and three D amino acids. The operon responsible for lugdunin synthesis is approximately 30 kb and contains four non ribosomal peptide synthetase genes. The operon contains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lugdunin NRPS
Lugdunin is an investigational antibiotic, classified as a thiazolidine-containing cyclic peptide. It was isolated in 2016 after ''Staphylococcus lugdunensis'' was identified as the species of bacteria from the human nose that suppressed growth of species of disease-causing bacteria in that part of the human microbiome. Lugdunin is a non-ribosomally synthesized cyclic peptide that inhibits growth of ''Staphylococcus aureus'' strains. The lugdunin genes are located on a 30-kbp operon. The genes ''lugA'', ''lugB'', ''lugC'', and ''lugD'' encode four non-ribosomal peptide synthases, which are preceded by a putative regulator gene ''lugR''. Biosynthesis Lugdunin is synthesized by non ribosomal peptide synthetases in ''S. lugdunensis''. The molecule is a cyclic peptide composed of a thiazolidine heterocycle and three D amino acids. The operon responsible for lugdunin synthesis is approximately 30 kb and contains four non ribosomal peptide synthetase genes. The operon contains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Lugdunensis
''Staphylococcus lugdunensis'' is a coagulase-negative member of the genus ''Staphylococcus'', consisting of Gram-positive bacteria with spherical cells that appear in clusters. History It was first described in 1988 after being differentiated through DNA analysis. Its name comes from ''Lugdunum'', the Latin name for Lyon, France, where the organism was first isolated. Description Colonies of ''S. lugdunensis'' are usually hemolytic, sticky, yellow or tan, and about 2–4 mm in diameter after a 48-hour incubation. They also can have a characteristic sweet, hay-like odor. ''S. lugdunensis'' may produce a bound coagulase (that is, the enzyme is bound to the cells), a property it shares with ''S. aureus'', but unlike ''S. aureus'', it does not produce a free coagulase. In the laboratory, it can give a positive slide-coagulase test but a negative tube-coagulase test. It is fairly easy to identify because, unlike the great majority of staphylococci, it decarboxylates ornithin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics. Sometimes, the term ''antibiotic''—literally "opposing life", from the Greek roots ἀντι ''anti'', "against" and βίος ''bios'', "life"—is broadly used to refer to any substance used against microbes, but in the usual medical usage, antibiotics (such as penicillin) are those produced naturally (by one microorganism fighting another), whereas non-antibiotic antibacterials (such as sulfonamides and antiseptics) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiazolidine
Thiazolidine is a heterocyclic organic compound with the formula (CH2)3(NH)S. It is a 5-membered saturated ring with a thioether group and an amine group in the 1 and 3 positions. It is a sulfur analog of oxazolidine. Thiazolidine is a colorless liquid. Derivatives, thiazolidines, are known. For example, the drug pioglitazone contains a thiazolidine ring. Another drug that contains a thiazolidine ring is the antibiotic penicillin. Preparation Thiazolidine is prepared as it was in its first reported synthesis, by the condensation of cysteamine and formaldehyde. Other thiazolidines may be synthesized by similar condensations. A notable derivative is 4-carboxythiazolidine, derived from formaldehyde and cysteine. Derivatives N-Methyl-2-thiazolidinethione is an accelerator for the vulcanization of chloroprene rubbers. Thiazolidines functionalized with carbonyls at the 2 and 4 positions, the thiazolidinediones, are drugs used in the treatment of diabetes mellitus type 2. Rhodanin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Peptide
Cyclic peptides are polypeptide chains which contain a circular sequence of bonds. This can be through a connection between the amino and carboxyl ends of the peptide, for example in cyclosporin; a connection between the amino end and a side chain, for example in bacitracin; the carboxyl end and a side chain, for example in colistin; or two side chains or more complicated arrangements, for example in amanitin. Many cyclic peptides have been discovered in nature and many others have been synthesized in the laboratory. Their length ranges from just two amino acid residues to hundreds. In nature they are frequently antimicrobial or toxic; in medicine they have various applications, for example as antibiotics and immunosuppressive agents. Thin-Layer Chromatography (TLC) is a convenient method to detect cyclic peptides in crude extract from bio-mass. Classification Cyclic peptides can be classified according to the types of bonds that comprise the ring. *Homodetic cyclic peptides, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Nose
The human nose is the most protruding part of the face. It bears the nostrils and is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones and the nasal cartilages, including the nasal septum which separates the nostrils and divides the nasal cavity into two. On average the nose of a male is larger than that of a female. The nose has an important function in breathing. The nasal mucosa lining the nasal cavity and the paranasal sinuses carries out the necessary conditioning of inhaled air by warming and moistening it. Nasal conchae, shell-like bones in the walls of the cavities, play a major part in this process. Filtering of the air by nasal hair in the nostrils prevents large particles from entering the lungs. Sneezing is a reflex to expel unwanted particles from the nose that irritate the mucosal lining. Sneezing can transmit infections, because aerosols are created in w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbiome
A microbiome () is the community of microorganisms that can usually be found living together in any given habitat. It was defined more precisely in 1988 by Whipps ''et al.'' as "a characteristic microbial community occupying a reasonably well-defined habitat which has distinct physio-chemical properties. The term thus not only refers to the microorganisms involved but also encompasses their theatre of activity". In 2020, an international panel of experts published the outcome of their discussions on the definition of the microbiome. They proposed a definition of the microbiome based on a revival of the "compact, clear, and comprehensive description of the term" as originally provided by Whipps ''et al.'', but supplemented with two explanatory paragraphs. The first explanatory paragraph pronounces the dynamic character of the microbiome, and the second explanatory paragraph clearly separates the term ''microbiota'' from the term ''microbiome''. The microbiota consists of all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles Times
The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the United States. The publication has won more than 40 Pulitzer Prizes. It is owned by Patrick Soon-Shiong and published by the Times Mirror Company. The newspaper’s coverage emphasizes California and especially Southern California stories. In the 19th century, the paper developed a reputation for civic boosterism and opposition to labor unions, the latter of which led to the bombing of its headquarters in 1910. The paper's profile grew substantially in the 1960s under publisher Otis Chandler, who adopted a more national focus. In recent decades the paper's readership has declined, and it has been beset by a series of ownership changes, staff reductions, and other controversies. In January 2018, the paper's staff voted to unionize and final ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. Although ''S. aureus'' usually acts as a commensal of the human microbiota, it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. ''S. aureus'' is one of the leading pathogens for deaths associated with antimicrobial resistance and the emergence of antibiotic-resistant strains, such as methicillin-resistant ''S. aureus'' (MRSA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operon
In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splicing to create monocistronic mRNAs that are translated separately, i.e. several strands of mRNA that each encode a single gene product. The result of this is that the genes contained in the operon are either expressed together or not at all. Several genes must be ''co-transcribed'' to define an operon. Originally, operons were thought to exist solely in prokaryotes (which includes organelles like plastids that are derived from bacteria), but since the discovery of the first operons in eukaryotes in the early 1990s, more evidence has arisen to suggest they are more common than previously assumed. In general, expression of prokaryotic operons leads to the generation of polycistronic mRNAs, while eukaryotic operons lead to monocistronic mRNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonribosomal Peptide
Nonribosomal peptides (NRP) are a class of peptide secondary metabolites, usually produced by microorganisms like bacteria and fungi. Nonribosomal peptides are also found in higher organisms, such as nudibranchs, but are thought to be made by bacteria inside these organisms. While there exist a wide range of peptides that are not synthesized by ribosomes, the term ''nonribosomal peptide'' typically refers to a very specific set of these as discussed in this article. Nonribosomal peptides are synthesized by nonribosomal peptide synthetases, which, unlike the ribosomes, are independent of messenger RNA. Each nonribosomal peptide synthetase can synthesize only one type of peptide. Nonribosomal peptides often have cyclic and/or branched structures, can contain non-proteinogenic amino acids including D-amino acids, carry modifications like '' N''-methyl and ''N''-formyl groups, or are glycosylated, acylated, halogenated, or hydroxylated. Cyclization of amino acids against the peptide " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonribosomal Peptide Synthetase
Nonribosomal peptides (NRP) are a class of peptide secondary metabolites, usually produced by microorganisms like bacteria and fungi. Nonribosomal peptides are also found in higher organisms, such as nudibranchs, but are thought to be made by bacteria inside Inside may refer to: * Insider, a member of any group of people of limited number and generally restricted access Film * ''Inside'' (1996 film), an American television film directed by Arthur Penn and starring Eric Stoltz * ''Inside'' (2002 f ... these organisms. While there exist a wide range of peptides that are not synthesized by ribosomes, the term ''nonribosomal peptide'' typically refers to a very specific set of these as discussed in this article. Nonribosomal peptides are synthesized by nonribosomal peptide synthetases, which, unlike the ribosomes, are independent of messenger RNA. Each nonribosomal peptide synthetase can synthesize only one type of peptide. Nonribosomal peptides often have cyclic compound, cyclic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
