|
Spheroplast
A spheroplast (or sphaeroplast in British usage) is a microbial cell from which the cell wall has been almost completely removed, as by the action of penicillin or lysozyme. According to some definitions, the term is used to describe Gram-negative bacteria. According to other definitions, the term also encompasses yeasts. The name spheroplast stems from the fact that after the microbe's cell wall is digested, membrane tension causes the cell to acquire a characteristic spherical shape. Spheroplasts are osmotically fragile, and will lyse if transferred to a hypotonic solution. When used to describe Gram-negative bacteria, the term spheroplast refers to cells from which the peptidoglycan component but not the outer membrane component of the cell wall has been removed. Spheroplast formation Antibiotic-induced spheroplasts Various antibiotics convert Gram-negative bacteria into spheroplasts. These include peptidoglycan synthesis inhibitors such as fosfomycin, vancomycin, moenomycin, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penicillin Spheroplast Generation
Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using deep tank fermentation and then purified. A number of natural penicillins have been discovered, but only two purified compounds are in clinical use: penicillin G (intramuscular or intravenous use) and penicillin V (given by mouth). Penicillins were among the first medications to be effective against many bacterial infections caused by staphylococci and streptococci. They are still widely used today for different bacterial infections, though many types of bacteria have developed resistance following extensive use. 10% of the population claims penicillin allergies but because the frequency of positive skin test results decreases by 10% with each year of avoidance, 90% of these patients can tolerate penicillin. Additionally, those with p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penicillin
Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using deep tank fermentation and then purified. A number of natural penicillins have been discovered, but only two purified compounds are in clinical use: penicillin G (intramuscular or intravenous use) and penicillin V (given by mouth). Penicillins were among the first medications to be effective against many bacterial infections caused by staphylococci and streptococci. They are still widely used today for different bacterial infections, though many types of bacteria have developed resistance following extensive use. 10% of the population claims penicillin allergies but because the frequency of positive skin test results decreases by 10% with each year of avoidance, 90% of these patients can tolerate penicillin. Additionally, those with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
β-lactam Antibiotic
β-lactam antibiotics (beta-lactam antibiotics) are antibiotics that contain a beta-lactam ring in their chemical structure. This includes penicillin derivatives (penams), cephalosporins and cephamycins (cephems), monobactams, carbapenems and carbacephems. Most β-lactam antibiotics work by inhibiting cell wall biosynthesis in the bacterial organism and are the most widely used group of antibiotics. Until 2003, when measured by sales, more than half of all commercially available antibiotics in use were β-lactam compounds. The first β-lactam antibiotic discovered, penicillin, was isolated from a rare variant of ''Penicillium notatum'' (since renamed ''Penicillium chrysogenum)''. Bacteria often develop resistance to β-lactam antibiotics by synthesizing a β-lactamase, an enzyme that attacks the β-lactam ring. To overcome this resistance, β-lactam antibiotics can be given with β-lactamase inhibitors such as clavulanic acid. Medical use β-lactam antibiotics are indicated for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fosfomycin
Fosfomycin, sold under the brand name Monurol among others, is an antibiotic primarily used to treat lower UTI. It is not indicated for kidney infections. Occasionally it is used for prostate infections. It is generally taken by mouth. Common side effects include diarrhea, nausea, headache, and vaginal yeast infections. Severe side effects may include anaphylaxis and ''Clostridium difficile''-associated diarrhea. While use during pregnancy has not been found to be harmful, such use is not recommended. A single dose when breastfeeding appears safe. Fosfomycin works by interfering with the production of the bacterial cell wall. Fosfomycin was discovered in 1969 and approved for medical use in the United States in 1996 . It is on the World Health Organization's List of Essential Medicines. The World Health Organization classifies fosfomycin as critically important for human medicine. It is available as a generic medication. It was originally produced by certain types of ''Stre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysozyme
Lysozyme (EC 3.2.1.17, muramidase, ''N''-acetylmuramide glycanhydrolase; systematic name peptidoglycan ''N''-acetylmuramoylhydrolase) is an antimicrobial enzyme produced by animals that forms part of the innate immune system. It is a glycoside hydrolase that catalyzes the following process: : Hydrolysis of (1→4)-β-linkages between ''N''-acetylmuramic acid and ''N''-acetyl-D-glucosamine residues in a peptidoglycan and between ''N''-acetyl-D-glucosamine residues in chitodextrins Peptidoglycan is the major component of gram-positive bacterial cell wall. This hydrolysis in turn compromises the integrity of bacterial cell walls causing lysis of the bacteria. Lysozyme is abundant in secretions including tears, saliva, human milk, and mucus. It is also present in cytoplasmic granules of the macrophages and the polymorphonuclear neutrophils (PMNs). Large amounts of lysozyme can be found in egg white. C-type lysozymes are closely related to α-lactalbumin in sequence and structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysis
Lysis ( ) is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" ) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a ''lysate''. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles. Many species of bacteria are subject to lysis by the enzyme lysozyme, found in animal saliva, egg white, and other secretions. Phage lytic enzymes (lysins) produced during bacteriophage infection are responsible for the ability of these viruses to lyse bacterial cells. Penicillin and related β-lactam antibiotics cause the death of bacteria through enzyme-mediated lysis that occurs after the drug causes the bacterium to form a defective cell wall. If the cell wall is completely lost and the penicillin was used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zymolyase
Zymolyase (also known as lyticase) is an enzyme mixture used to degrade the cell wall of yeast and form spheroplasts. Essential activities of zymolyase include β-1,3-glucan laminaripentao-hydrolase activity and β-1,3-glucanase activity. A common source of zymolyase is the Actinobacteria ''Arthrobacter luteus''. Commercial sources of zymolyase may have some residual protease activity. Fungi susceptible to zymolyase can be found in the order Saccharomycetales. Saccharomycetales genera that zymolyase is known to have activity against include: '' Eremothecium'', '' Candida'', ''Debaryomyces'', '' Eremothecium'', ''Endomyces'', ''Hansenula'', ''Hanseniaspora'', ''Kloekera'', ''Kluyveromyces'', '' Lipomyces'', ''Metschikowia'', ''Pichia'', ''Pullularia'', ''Saccharomyces'', ''Saccharomycopsis'', ''Schizosaccahromyces'', ''Torulopsis ''Candida'' is a genus of yeasts and is the most common cause of fungal infections worldwide. Many species are harmless Commensalism, commensals or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfamethoxazole
Sulfamethoxazole (SMZ or SMX) is an antibiotic. It is used for bacterial infections such as urinary tract infections, bronchitis, and prostatitis and is effective against both gram negative and positive bacteria such as ''Listeria monocytogenes'' and ''E. coli''. Common side effects include nausea, vomiting, loss of appetite, and skin rashes. It is a sulfonamide and bacteriostatic. It resembles a component of folic acid. It prevents folic acid synthesis in the bacteria that must synthesize their own folic acid. Mammalian cells, and some bacteria, do not synthesize but require preformed folic acid (vitamin B9); they are therefore insensitive to sulfamethoxazole. It was introduced to the United States in 1961. It is now mostly used in combination with trimethoprim (abbreviated SMX-TMP). The SMX-TMP combination is on the WHO Model List of Essential medicines as a first-choice treatment for urinary tract infections. Other names include: sulfamethalazole, sulfisomezole,PubChem"Sul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactoferrin
Lactoferrin (LF), also known as lactotransferrin (LTF), is a multifunctional protein of the transferrin family. Lactoferrin is a globular glycoprotein with a molecular mass of about 80 kDa that is widely represented in various secretory fluids, such as milk, saliva, tears, and nasal secretions. Lactoferrin is also present in secondary granules of PMNs and is secreted by some acinar cells. Lactoferrin can be purified from milk or produced recombinantly. Human colostrum (''"first milk"'') has the highest concentration, followed by human milk, then cow milk (150 mg/L). Lactoferrin is one of the components of the immune system of the body; it has antimicrobial activity (bacteriocide, fungicide) and is part of the innate defense, mainly at mucoses. In particular, lactoferrin provides antibacterial activity to human infants. Lactoferrin interacts with DNA and RNA, polysaccharides and heparin, and shows some of its biological functions in complexes with these ligands. Lactoferri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethylenediaminetetraacetic Acid
Ethylenediaminetetraacetic acid (EDTA) is an aminopolycarboxylic acid with the formula H2N(CH2CO2H)2sub>2. This white, water-soluble solid is widely used to bind to iron (Fe2+/Fe3+) and calcium ions (Ca2+), forming water-soluble complexes even at neutral pH. It is thus used to dissolve Fe- and Ca-containing scale as well as to deliver iron ions under conditions where its oxides are insoluble. EDTA is available as several salts, notably disodium EDTA, sodium calcium edetate, and tetrasodium EDTA, but these all function similarly. Uses Textile industry In industry, EDTA is mainly used to sequester (bind or confine) metal ions in aqueous solution. In the textile industry, it prevents metal ion impurities from modifying colours of dyed products. In the pulp and paper industry, EDTA inhibits the ability of metal ions, especially Mn2+, from catalysing the disproportionation of hydrogen peroxide, which is used in chlorine-free bleaching. In a similar manner, EDTA is added to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Candida Albicans
''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is usually a commensal organism, but it can become pathogenic in immunocompromised individuals under a variety of conditions. It is one of the few species of the genus '' Candida'' that causes the human infection candidiasis, which results from an overgrowth of the fungus. Candidiasis is, for example, often observed in HIV-infected patients. ''C. albicans'' is the most common fungal species isolated from biofilms either formed on (permanent) implanted medical devices or on human tissue. ''C. albicans'', ''C. tropicalis'', ''C. parapsilosis'', and ''C. glabrata'' are together responsible for 50–90% of all cases of candidiasis in humans. A mortality rate of 40% has been reported for patients with systemic candidiasis due to ''C. albicans''. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Outer Membrane
The bacterial outer membrane is found in gram-negative bacteria. Its composition is distinct from that of the inner cytoplasmic cell membrane - among other things, the outer leaflet of the outer membrane of many gram-negative bacteria includes a complex lipopolysaccharide whose lipid portion acts as an endotoxin - and in some bacteria such as ''E. coli'' it is linked to the cell's peptidoglycan by Braun's lipoprotein. Porins can be found in this layer. Clinical significance If lipid A, part of the lipopolysaccharide, enters the circulatory system it causes a toxic reaction by activating toll like receptor TLR 4. Lipid A is very pathogenic and not immunogenic. However, the polysaccharide component is very immunogenic, but not pathogenic, causing an aggressive response by the immune system. The sufferer will have a high temperature and respiration rate and a low blood pressure. This may lead to endotoxic shock, which may be fatal. The bacterial outer membrane is physiologicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
