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Narrow-spectrum Antibiotic
A narrow-spectrum antibiotic is an antibiotic that is only able to kill or inhibit limited species of bacteria. Examples of narrow-spectrum antibiotics include fidaxomicin and sarecycline. Advantages * Narrow-spectrum antibiotic allow to kill or inhibit only those bacteria species that are unwanted (i.e. causing disease). As such, it leaves most of the beneficial bacteria unaffected, hence minimizing the collateral damage on the microbiota. *Low propensity for bacterial resistance development. Disadvantages Often, the exact species of bacteria causing the illness is unknown, in which case narrow-spectrum antibiotics can't be used, and broad-spectrum antibiotics are used instead. To know the exact species of bacteria causing the illness, clinical specimens need to be taken for antimicrobial susceptibility testing in a clinical microbiology laboratory. See also * Broad-spectrum antibiotic A broad-spectrum antibiotic is an antibiotic that acts on the two major bacterial groups, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimicrobial Spectrum
The antimicrobial spectrum of an antibiotic means the range of microorganisms it can kill or inhibit. Antibiotics can be divided into broad-spectrum antibiotics, extended-spectrum antibiotics and narrow-spectrum antibiotics based on their spectrum of activity. Detailedly, broad-spectrum antibiotics can kill or inhibit a wide range of microorganisms; extended-spectrum antibiotic can kill or inhibit Gram positive bacteria and some Gram negative bacteria; narrow-spectrum antibiotic can only kill or inhibit limited species of bacteria. Currently no antibiotic's spectrum can completely cover all types of microorganisms. Determination The antimicrobial spectrum of an antibiotic can be determined by testing its antimicrobial activity against a wide range of microbes ''in vitro ''. Nonetheless, the range of microorganisms which an antibiotic can kill or inhibit ''in vivo'' may not always be the same as the antimicrobial spectrum based on data collected in vitro. Significance Narrow-spec ... [...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] |
Fidaxomicin
Fidaxomicin, sold under the brand name Dificid among others, is the first member of a class of narrow spectrum macrocyclic antibiotic drugs called tiacumicins. It is a fermentation product obtained from the actinomycete ''Dactylosporangium aurantiacum'' subspecies ''hamdenesis''. Fidaxomicin is minimally absorbed into the bloodstream when taken orally, is bactericidal, and selectively eradicates pathogenic ''Clostridioides difficile'' with relatively little disruption to the multiple species of bacteria that make up the normal, healthy intestinal microbiota. The maintenance of normal physiological conditions in the colon may reduce the probability of recurrence of ''Clostridioides difficile'' infection. It is marketed by Merck, which acquired Cubist Pharmaceuticals in 2015, and had in turn bought the originating company, Optimer Pharmaceuticals. It is used for the treatment of ''Clostridioides difficile'' infection, which is also known as ''Clostridioides difficile''-associate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarecycline
Sarecycline is a narrow-spectrum tetracycline-derived antibiotic. It is specifically designed for the treatment of acne, and was approved by the FDA in October 2018 for the treatment of inflammatory lesions of non-nodular moderate to severe acne vulgaris in patients 9 years of age and older. Two randomized and well-controlled clinical trials reported efficacy data on both facial and truncal acne (back and chest). Efficacy was assessed in a total of 2002 subjects 9 years of age and older. Unlike other tetracycline-class antibiotics, sarecycline has a long C7 moiety that extends into and directly interact with the bacterial messenger RNA (mRNA). The spectrum of activity is limited to clinically relevant Gram-positive bacteria, mainly ''Cutibacterium acnes'', with little or no activity against Gram-negative bacterial microflora commonly found in the human gastrointestinal tract. Sarecycline has not been tested in spirochetes A spirochaete () or spirochete is a member of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Microbiome
The human microbiome is the aggregate of all microbiota that reside on or within human tissues and biofluids along with the corresponding anatomical sites in which they reside, including the skin, mammary glands, seminal fluid, uterus, ovarian follicles, lung, saliva, oral mucosa, conjunctiva, biliary tract, and gastrointestinal tract. Types of human microbiota include bacteria, archaea, fungi, protists and viruses. Though micro-animals can also live on the human body, they are typically excluded from this definition. In the context of genomics, the term ''human microbiome'' is sometimes used to refer to the collective genomes of resident microorganisms; however, the term '' human metagenome'' has the same meaning. Humans are colonized by many microorganisms, with approximately the same order of magnitude of non-human cells as human cells. Some microorganisms that colonize humans are commensal, meaning they co-exist without harming humans; others have a mutualistic relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimicrobial Resistance
Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. Protozoa evolve antiprotozoal resistance, and bacteria evolve antibiotic resistance. Those bacteria that are considered extensively drug resistant (XDR) or totally drug-resistant (TDR) are sometimes called "superbugs".A.-P. Magiorakos, A. Srinivasan, R. B. Carey, Y. Carmeli, M. E. Falagas, C. G. Giske, S. Harbarth, J. F. Hinndler ''et al''Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria... Clinical Microbiology and Infection, Vol 8, Iss. 3 first published 27 July 2011 ia Wiley Online Library Retrieved 28 August 2020 Although antimicrobial resistance is a naturally-occurring process, it is often the result of improper usage of the drugs and management of the infections. Antibiotic resistance is a major subset o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Microbiology
Medical microbiology, the large subset of microbiology that is applied to medicine, is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. In addition, this field of science studies various clinical applications of microbes for the improvement of health. There are four kinds of microorganisms that cause infectious disease: bacteria, fungi, parasites and viruses, and one type of infectious protein called prion. A medical microbiologist studies the characteristics of pathogens, their modes of transmission, mechanisms of infection and growth. The academic qualification as a clinical/Medical Microbiologist in a hospital or medical research centre generally requires a Masters in Microbiology along with Ph.D. in any of the life-sciences (Biochem, Micro, Biotech, Genetics, etc.). Medical microbiologists often serve as consultants for physicians, providing identification of pathogens and suggesting treatment options. Using this infor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broad-spectrum Antibiotic
A broad-spectrum antibiotic is an antibiotic that acts on the two major bacterial groups, Gram-positive and Gram-negative, or any antibiotic that acts against a wide range of disease-causing bacteria. These medications are used when a bacterial infection is suspected but the group of bacteria is unknown (also called empiric therapy) or when infection with multiple groups of bacteria is suspected. This is in contrast to a narrow-spectrum antibiotic, which is effective against only a specific group of bacteria. Although powerful, broad-spectrum antibiotics pose specific risks, particularly the disruption of native, normal bacteria and the development of antimicrobial resistance. An example of a commonly used broad-spectrum antibiotic is ampicillin. Bacterial targets Antibiotics are often grouped by their ability to act on different bacterial groups. Although bacteria are biologically classified using taxonomy, disease-causing bacteria have historically been classified by their micro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
