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β-lactamase
Beta-lactamases (β-lactamases) are enzymes () produced by bacteria that provide Multiple drug resistance, multi-resistance to beta-lactam antibiotics such as penicillins, cephalosporins, cephamycins, monobactams and carbapenems (ertapenem), although carbapenems are relatively resistant to beta-lactamase. Beta-lactamase provides antibiotic resistance by breaking the antibiotics' structure. These antibiotics all have a common element in their molecular structure: a four-atom ring known as a beta-lactam (β-lactam) ring. Through hydrolysis, the enzyme lactamase breaks the β-lactam ring open, deactivating the molecule's antibacterial properties. Beta-lactamases produced by gram-negative bacteria are usually secreted, especially when antibiotics are present in the environment. Structure The structure of a ''Streptomyces'' serine β-lactamase (SBLs) is given by . The alpha-beta fold () resembles that of a DD-Transpeptidase, DD-transpeptidase, from which the enzyme is thoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penicillin
Penicillins (P, PCN or PEN) are a group of beta-lactam antibiotic, β-lactam antibiotics originally obtained from ''Penicillium'' Mold (fungus), moulds, principally ''Penicillium chrysogenum, P. chrysogenum'' and ''Penicillium rubens, P. rubens''. Most penicillins in clinical use are synthesised by ''Penicillium chrysogenum, P. chrysogenum'' using industrial fermentation, deep tank fermentation and then purified. A number of natural penicillins have been discovered, but only two purified compounds are in clinical use: benzylpenicillin, penicillin G (intramuscular injection, intramuscular or Intravenous therapy, intravenous use) and phenoxymethylpenicillin, penicillin V (given by mouth). Penicillins were among the first medications to be effective against many bacterial infections caused by staphylococcus, staphylococci and streptococcus, streptococci. They are still widely used today for various bacterial infections, though many types of bacteria have developed antibiotic res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalosporin
The cephalosporins (sg. ) are a class of β-lactam antibiotics originally derived from the fungus '' Acremonium'', which was previously known as ''Cephalosporium''. Together with cephamycins, they constitute a subgroup of β-lactam antibiotics called cephems. Cephalosporins were discovered in 1945, and first sold in 1964. Discovery The aerobic mold which yielded cephalosporin C was found in the sea near a sewage outfall in Su Siccu, by Cagliari harbour in Sardinia, by the Italian pharmacologist Giuseppe Brotzu in July 1945. Structure Cephalosporin contains a 6-membered dihydrothiazine ring. Substitutions at position 3 generally affect pharmacology; substitutions at position 7 affect antibacterial activity, but these cases are not always true. Medical uses Cephalosporins can be indicated for the prophylaxis and treatment of infections caused by bacteria susceptible to this particular form of antibiotic. First-generation cephalosporins are active predominant ... [...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 pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy, treatment and antibiotic prophylaxis, prevention of such infections. They may either bactericide, kill or bacteriostatic agent, inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the ones which cause the common cold or influenza. Drugs which inhibit growth of viruses are termed antiviral drugs or antivirals. Antibiotics are also not effective against fungi. Drugs which inhibit growth of fungi are called antifungal drugs. Sometimes, the term ''antibiotic''—literally "opposing life", from the Greek language, Greek roots ἀντι ''anti'', "against" and βίος ''bios'', "life"—is broadly used to refer to any substance used against ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbapenem
Carbapenems are a class of very effective antibiotic agents most commonly used for treatment of severe bacterial infections. This class of antibiotics is usually reserved for known or suspected multidrug-resistant (MDR) bacterial infections. Similar to penicillins and cephalosporins The cephalosporins (sg. ) are a class of β-lactam antibiotics originally derived from the fungus ''Acremonium'', which was previously known as ''Cephalosporium''. Together with cephamycins, they constitute a subgroup of β-lactam antibiotic ..., carbapenems are members of the beta-lactam antibiotics drug class, which kill bacteria by binding to penicillin-binding proteins, thus inhibiting bacterial cell wall synthesis. However, these agents individually exhibit a broader spectrum of activity compared to most cephalosporins and penicillins. Furthermore, carbapenems are typically unaffected by emerging antibiotic resistance, even to other beta-lactams. Carbapenem antibiotics were originall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cefotaxime
Cefotaxime is an antibiotic used to treat several bacterial infections in humans, other animals, and plant tissue culture. Specifically in humans it is used to treat joint infections, pelvic inflammatory disease, meningitis, pneumonia, urinary tract infections, sepsis, gonorrhea, and cellulitis. It is given either by injection into a vein or muscle. Common side effects include nausea, allergic reactions, and inflammation at the site of injection. Another side effect may include ''Clostridioides difficile'' diarrhea. It is not recommended in people who have had previous anaphylaxis to a penicillin. It is relatively safe for use during pregnancy and breastfeeding. It is in the third-generation cephalosporin family of medications and works by interfering with the bacteria's cell wall. Cefotaxime was discovered in 1976 and came into commercial use in 1980. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methicillin
Methicillin ( USAN), also known as meticillin ( INN), is a narrow-spectrum β-lactam antibiotic of the penicillin class. Methicillin was discovered in 1960. Medical uses Compared to other penicillins that face antimicrobial resistance due to β-lactamase, it is less active, can be administered only parenterally, and has a higher frequency of interstitial nephritis, an otherwise-rare adverse effect of penicillins. However, selection of methicillin depended on the outcome of susceptibility testing of the sampled infection, and since it is no longer produced, it is also not routinely tested for any more. It also served a purpose in the laboratory to determine the antibiotic sensitivity of ''Staphylococcus aureus'' to other penicillins facing β-lactam resistance; this role has now been passed on to other penicillins, namely '' cloxacillin'', as well as genetic testing for the presence of '' mecA'' gene by '' PCR''. Spectrum of activity At one time, methicillin was u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic 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), 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 overuse, both in medicine and agriculture, which accelerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Delhi Metallo-beta-lactamase 1
NDM-1 is an enzyme that makes bacteria Antibiotic resistance, resistant to a broad range of beta-lactam antibiotics. These include the antibiotics of the carbapenem family, which are a mainstay for the treatment of antibiotic-resistant bacterial infections. The gene for NDM-1 is one member of a large gene family that encodes beta-lactamase enzymes called Beta-lactamase#Carbapenemases, carbapenemases. Bacteria that produce carbapenemases are often referred to in the news media as "Antibiotic resistance, superbugs" because infections caused by them are difficult to treat. Such bacteria are usually sensitive only to polymyxins and tigecycline. NDM-1 was first detected in 2008 in a culture plate of ''Klebsiella pneumoniae'' isolated from a Sweden, Swedish patient of Indian origin. It was later detected in bacteria in India, Pakistan, the United Kingdom, the United States, Canada, Japan, Egypt, and Iraq. The most common bacteria that make this enzyme are Gram-negative bacteria, gram-n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterobacter Cloacae
''Enterobacter cloacae'' is a clinically significant Gram-negative, facultatively-anaerobic, rod-shaped bacterium. Microbiology In microbiology laboratories, ''E. cloacae'' is frequently grown at 30 °C on nutrient agar or at 35 °C in tryptic soy broth. It is a rod-shaped, Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ... bacterium, is facultatively anaerobic, and bears peritrichous flagella. It is oxidase-negative and catalase-positive. Industrial use ''Enterobacter cloacae'' has been used in a bioreactor-based method for the biodegradation of explosives and in the biological control of plant diseases. ''Enterobacter cloacae'' strain MBB8 isolated from the Gulf of Mannar, India was reported to degrade poly vinyl alcohol (PVA). This was the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceftriaxone
Ceftriaxone, sold under the brand name Rocephin, is a third-generation cephalosporin antibiotic used for the treatment of a number of bacterial infections. These include middle ear infections, endocarditis, meningitis, pneumonia, bone and joint infections, intra-abdominal infections, skin infections, urinary tract infections, gonorrhea, and pelvic inflammatory disease. It is also sometimes used before surgery and following a bite wound to try to prevent infection. Ceftriaxone can be given by injection into a vein or into a muscle. Common side effects include pain at the site of injection and allergic reactions. Other possible side effects include ''C. difficile''-associated diarrhea, hemolytic anemia, gall bladder disease, and seizures. It is not recommended in those who have had anaphylaxis to penicillin but may be used in those who have had milder reactions. The intravenous form should not be given with intravenous calcium. There is tentative evidence that ceftriaxone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrobacter Freundii
''Citrobacter'' is a genus of Gram-negative, aerobic, rod-shaped coliform bacteria of the Enterobacteriaceae family. ''Citrobacter'' spp. cause opportunistic infections (including urinary tract infections, gastroenteritis, and bacteremia). Microbiology Microbial biochemistry The species ''C. amalonaticus'', '' C. koseri'', and '' C. freundii'' can use citrate as a sole carbon source. ''Citrobacter'' species are differentiated by their ability to convert tryptophan to indole (''C. koseri'' is the only citrobacter to be commonly indole-positive), ferment lactose (''C. koseri'' is a lactose fermentor), and use malonate. ''Citrobacter'' shows the ability to accumulate uranium by building phosphate complexes. Environmental microbiology These bacteria can be found almost everywhere in soil, water, wastewater, etc. They can also be found in the human intestine. Clinical significance Citrobacter are considered opportunistic nosocomial pathogens, typically associated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
