|
Quinolone Antibiotic
Quinolone antibiotics constitute a large group of broad-spectrum bacteriocidals that share a bicyclic core structure related to the substance 4-quinolone. They are used in human and veterinary medicine to treat bacterial infections, as well as in animal husbandry, specifically poultry production. Quinolone antibiotics are classified into four generations based on their spectrum of activity and chemical modifications. The first-generation quinolones, such as nalidixic acid, primarily target Gram-negative bacteria and are mainly used for urinary tract infections. Second-generation quinolones introduced fluorine atoms into their structure, creating fluoroquinolones, which significantly expanded their antibacterial activity to include some Gram-positive bacteria. Third-generation fluoroquinolones further improved Gram-positive coverage, while fourth-generation fluoroquinolones offer broad-spectrum activity, including anaerobic bacteria. Only quinolone antibiotics in generat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-Quinolone
4-Quinolone is an organic compound derived from quinoline. It and 2-quinolone are the two most important parent (meaning simplified) quinolones. 4-Quinolone exists in equilibrium with a minor tautomer, 4-hydroxyquinoline (CAS#611-36-9). Aside from pedagogical interest, 4-quinolone is of little intrinsic value but its derivatives, the Quinolone antibiotic, 4-quinolone antibiotics, represent a large class of important drugs. Synthesis The chemical synthesis of quinolones often involves ring-closing reactions.{{cite journal, title=Co(III)-Catalyzed Enaminone-Directed C-H Amidation for Quinolone Synthesis, author=Shi, Pengfei, author2=Wang, Lili, author3=Chen, Kehao, author4=Wang, Jie, author5=Zhu, Jin, journal= Organic Letters, year=2017, volume=19, issue=9, pages=2418–2421, pmid=28425721, doi=10.1021/acs.orglett.7b00968 Such reactions often install a hydroxyl group (an –OH functional group) on the carbon across from the ring nitrogen (i.e., the C-4 positions). An example o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multidrug Resistance
Multiple drug resistance (MDR), multidrug resistance or multiresistance is antimicrobial resistance shown by a species of microorganism to at least one antimicrobial drug in three or more antimicrobial categories. Antimicrobial categories are classifications of antimicrobial agents based on their mode of action and specific to target organisms. The MDR types most threatening to public health are MDR bacteria that resist multiple antibiotics; other types include MDR viruses, parasitism, parasites (resistant to multiple antifungal, antiviral drug, antiviral, and antiparasitic drugs of a wide chemical variety). Recognizing different degrees of MDR in bacteria, the terms ''extensively drug-resistant'' (''XDR'') and ''pandrug-resistant'' (''PDR'') have been introduced. ''Extensively drug-resistant (XDR)'' is the non-susceptibility of one bacteria species to all antimicrobial agents except in two or less antimicrobial categories. Within XDR, ''pandrug-resistant (PDR)'' is the non-sus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daptomycin
Daptomycin, sold under the brand name Cubicin among others, is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms. Daptomycin was removed from the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines in 2019. The World Health Organization classifies daptomycin as critically important for human medicine. Medical uses In the United States, daptomycin is Indication (medicine), indicated for use in adults for skin and skin structure infections caused by Gram-positive infections, ''S. aureus'' bacteraemia, and right-sided ''S. aureus'' endocarditis. It binds avidly to pulmonary surfactant, so cannot be used in the treatment of pneumonia. There seems to be a difference in working daptomycin on hematogenous pneumonia. Adverse effects Common adverse drug reactions associated with daptomycin therapy include: * Cardiovascular: hypotension, low blood pressure, hypertens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetracycline
Tetracycline, sold under various brand names, is an antibiotic in the tetracyclines family of medications, used to treat a number of infections, including acne, cholera, brucellosis, plague, malaria, and syphilis. It is available in oral and topical formulations. Common side effects include vomiting, diarrhea, rash, and loss of appetite. Other side effects include poor tooth development if used by children less than eight years of age, kidney problems, and sunburning easily. Use during pregnancy may harm the baby. It works by inhibiting protein synthesis in bacteria. Tetracycline was patented in 1953 and was approved for prescription use in 1954. It is on the World Health Organization's List of Essential Medicines. Tetracycline is available as a generic medication. Tetracycline was originally made from bacteria of the genus ''Streptomyces''. Medical uses Spectrum of activity Tetracyclines have a broad spectrum of antibiotic action. Originally, they possessed some lev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycopeptide Antibiotics
Glycopeptide antibiotics are a class of drugs of microbial origin that are composed of glycosylated cyclic or polycyclic nonribosomal peptides. Significant glycopeptide antibiotics include the anti-infective antibiotics vancomycin, teicoplanin, telavancin, ramoplanin, avoparcin and decaplanin, corbomycin, complestatin and the antitumor antibiotic bleomycin. Vancomycin is used if infection with methicillin-resistant Staphylococcus aureus, methicillin-resistant ''Staphylococcus aureus'' (MRSA) is suspected. Mechanism and classification Some members of this class of drugs inhibit the synthesis of cell walls in susceptible microbes by inhibiting peptidoglycan synthesis. The core class (including vancomycin) binds to acyl-D-alanyl-D-alanine in lipid II, preventing the addition of new units to the peptidoglycan. Of this core class, one may distinguish multiple generations: the first generation includes vancomycin and teicoplanin, while the semisynthetic second generation incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofilm
A biofilm is a Syntrophy, syntrophic Microbial consortium, community of microorganisms in which cell (biology), cells cell adhesion, stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric combination of extracellular polysaccharides, proteins, lipids and DNA. Because they have a three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes". Biofilms may form on living (biotic) or non-living (abiotic) surfaces and can be common in natural, industrial, and hospital settings. They may constitute a microbiome or be a portion of it. The microbial cells growing in a biofilm are physiology, physiologically distinct from planktonic cells of the same organism, which, by contrast, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetracyclines
Tetracyclines are a group of broad-spectrum antibiotic compounds that have a common basic structure and are either isolated directly from several species of ''Streptomyces'' bacteria or produced semi-synthetically from those isolated compounds. Tetracycline molecules comprise a linear fused tetracyclic nucleus (rings designated A, B, C and D) to which a variety of functional groups are attached. Tetracyclines are named after their four ("tetra-") hydrocarbon rings ("-cycl-") derivation ("-ine"). They are defined as a subclass of polyketides, having an octahydrotetracene-2-carboxamide skeleton and are known as derivative (chemistry), derivatives of polycyclic naphthacene carboxamide. While all tetracyclines have a common structure, they differ from each other by the presence of chloro, methyl, and hydroxyl groups. These chemical modification, modifications do not change their broad antibacterial activity, but do affect pharmacological properties such as half-life and binding to pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelation
Chelation () is a type of bonding of ions and their molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are called chelants, chelators, chelating agents, or sequestering agents. They are usually organic compounds, but this is not a necessity. The word ''chelation'' is derived from Greek χηλή, ''chēlē'', meaning "claw"; the ligands lie around the central atom like the claws of a crab. The term ''chelate'' () was first applied in 1920 by Sir Gilbert T. Morgan and H. D. K. Drew, who stated: "The adjective chelate, derived from the great claw or ''chele'' (Greek) of the crab or other crustaceans, is suggested for the caliperlike groups which function as two associating units and fasten to the central atom so as to produce heterocyclic rings." Chelation is useful in applications such as providing nutritional supplements, in chel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmonella
''Salmonella'' is a genus of bacillus (shape), rod-shaped, (bacillus) Gram-negative bacteria of the family Enterobacteriaceae. The two known species of ''Salmonella'' are ''Salmonella enterica'' and ''Salmonella bongori''. ''S. enterica'' is the type species and is further divided into six subspecies that include over 2,650 serotypes. ''Salmonella'' was named after Daniel Elmer Salmon (1850–1914), an American veterinary surgeon. ''Salmonella'' species are non-Endospore, spore-forming, predominantly motility, motile enterobacteriaceae, enterobacteria with cell diameters between about 0.7 and 1.5 micrometre, μm, lengths from 2 to 5 μm, and peritrichous flagella (all around the cell body, allowing them to move). They are chemotrophs, obtaining their energy from Redox, oxidation and reduction reactions, using organic sources. They are also facultative aerobic organism, facultative anaerobes, capable of generating adenosine triphosphate with oxygen ("aerobically") ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteomyelitis
Osteomyelitis (OM) is the infectious inflammation of bone marrow. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The feet, spine, and hips are the most commonly involved bones in adults. The cause is usually a bacterial infection, but rarely can be a fungal infection. It may occur by spread from the blood or from surrounding tissue. Risks for developing osteomyelitis include diabetes, intravenous drug use, prior splenectomy, removal of the spleen, and trauma to the area. Diagnosis is typically suspected based on symptoms and basic laboratory tests as C-reactive protein and erythrocyte sedimentation rate. This is because plain radiographs are unremarkable in the first few days following acute infection. Diagnosis is further confirmed by blood tests, medical imaging, or bone biopsy. Treatment of bacterial osteomyelitis often involves both antimicrobials and surgery. Treatment outcomes of bacterial osteomyelitis are generally good when t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sickle-cell Disease
Sickle cell disease (SCD), also simply called sickle cell, is a group of inherited haemoglobin-related blood disorders. The most common type is known as sickle cell anemia. Sickle cell anemia results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. This leads to the red blood cells adopting an abnormal sickle-like shape under certain circumstances; with this shape, they are unable to deform as they pass through capillaries, causing blockages. Problems in sickle cell disease typically begin around 5 to 6 months of age. A number of health problems may develop, such as attacks of pain (known as a sickle cell crisis) in joints, anemia, swelling in the hands and feet, bacterial infections, dizziness and stroke. The probability of severe symptoms, including long-term pain, increases with age. Without treatment, people with SCD rarely reach adulthood but with good healthcare, median life expectancy is between 58 and 66 years. All of the majo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
