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AmpC β-lactamase
Beta-lactamases (β-lactamases) are enzymes () produced by bacteria that provide 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, from which the enzyme is thought to have evolved. β-lactam antibiotics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptomyces Albus
''Streptomyces albus'' is a bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...l species from which the pseudodisaccharide aminoglycoside salbostatin was isolated. ''S. albus'' is known to produce white aerial mycelium. References Further reading * External linksType strain of ''Streptomyces albus'' at Bac''Dive'' - the Bacterial Diversity Metadatabase albus {{Streptomyces-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacteria
Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the Crystal violet, crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists of a thin peptidoglycan gram-negative cell wall, cell wall sandwiched between an inner (Cytoplasm, cytoplasmic) Cell membrane, membrane and an Bacterial outer membrane, outer membrane. These bacteria are found in all environments that support life on Earth. Within this category, notable species include the model organism ''Escherichia coli'', along with various pathogenic bacteria, such as ''Pseudomonas aeruginosa'', ''Chlamydia trachomatis'', and ''Yersinia pestis''. They pose significant challenges in the medical field due to their outer membrane, which acts as a protective barrier against numerous Antibiotic, antibiotics (including penicillin), Detergent, detergents that would normally damage the inner cell membrane, and the ... [...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] |
Ceftizoxime
Ceftizoxime is a third-generation cephalosporin available for parenteral administration. Unlike other third-generation cephalosporins, the whole C-3 side chain in ceftizoxime has been removed to prevent deactivation by hydrolytic enzymes. It rather resembles cefotaxime in its properties, but is not subject to metabolism. It was removed from the US Market in 2007. Synthesis Injectable third generation cephalosporin antibiotic related to 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, urin ..., q.v. Exhibits broad spectrum activity and resistance to β-lactamase hydrolysis. References Cephalosporin antibiotics Thiazoles {{antibiotic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteus Mirabilis
''Proteus mirabilis'' is a Gram-negative, facultatively Anaerobic organism, anaerobic, rod-shaped bacterium. It shows swarming motility and urease activity. ''P. mirabilis'' causes 90% of all ''Proteus (bacterium), Proteus'' infections in humans. It is widely distributed in soil and water. ''Proteus mirabilis'' can migrate across the surface of solid media or devices using a type of cooperative group motility called swarming. ''Proteus mirabilis'' is most frequently associated with Urinary tract infection, infections of the urinary tract, especially in complicated or catheter-associated urinary tract infections. Diagnosis An alkaline urine sample is a possible sign of ''P. mirabilis''. It can be diagnosed in the lab due to characteristic swarming motility, and inability to metabolize lactose (on a MacConkey agar plate, for example). Also ''P. mirabilis'' produces a very distinct fishy odor. Disease This rod-shaped bacterium has the ability to produce high levels of urease, whi ... [...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] |
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] |
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] |
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] |
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] |
RNase Z
TRNase Z (, ''3 tRNase'', ''tRNA 3 endonuclease'', ''RNase Z'', ''3' tRNase'') is an enzyme that, among other things, catalyses the reactions involved in the maturation of tRNAs. Here, it endonucleolytically cleaves the RNA and removes extra 3' nucleotides from the tRNA precursor, generating the 3' termini of tRNAs. A 3'-hydroxy group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ... is left at the tRNA terminus and a 5'- phosphoryl group is left at the trailer molecule. Similarly, it processes tRNA-like molecules such as mascRNA. References External links * {{Portal bar, Biology, border=no EC 3.1.26 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
