Broad-spectrum antibiotic

Antibiotic broad-spectrum agent inhibits protein synthesis (SOS) uses restricted to backup drug for bacterial meningitis, infections due to anaerobes, salmonella. Tox reversible myelosuppression, aplastic anemia, gray baby syndrome. 

Tetracyclines are broad-spectrum antibiotics. effective against Gram-positive and Gram-negative bacteria, also against Rickettsiae (typhus fever) and certain other organisms. 

Before the discovery of streptomycin, pyrazinamide (126) was one of the front runners in the treatment of tuberculosis. A broad spectrum of biological activity has been associated with pyrazine derivatives, ranging from the herbicidal activity of (127) to antibiotic activity... 

The tetracyclines are valuable orally active broad-spectrum antibiotics prepared by isolation from the fermentation liquors of various strains of Streptomyces or by chemical transformation of fermentation-derived substances. The basic ring system and numbering pattern is as follows ... 

One of the most popular orally active penicillins in present clinical use is amoxicillin (12). Its oral effectiveness and broad spectrum of activity against common pathogens as well as its better absorption than its closest precedent competitor, ampicillin (14), largely accounts for this. Higher blood and tissue levels of antibiotics is another means of dealing with resistance. In an attempt to achieve yet further improvements in oral bioavailability and hence blood and ti.ssue levels of amoxicillin, the prodmg fumoxicillin (13) is prepared from amoxicillin (12) by treatment with furfural [3]. The imine moiety is less basic than the primary amine so that the isoelectric point of fumoxicillin is more on the acid side than is that of amoxicillin. 

Chloramphenicol, a powerful antibiotic isolated in 1949 from the Streptomyces venezuelae bacterium, is active against a broad spectrum of bacterial infections and is particularly valuable against typhoid fever. Assign R,S configurations to the chirality centers in chloramphenicol. 

Erylhronoljde B is the biological precursor of erythromycin, a broad-spectrum antibiotic. How many chirality centers does erythronolide B have ... 

Azirinomycin (129 Scheme 11.19) was isolated as a broad-spectrum antibiotic from Streptomyces aureus by workers at Merck, Sharp, and Dohme in 1971 [192,... 

Promoting Optimal Response to Therapy The results of a culture and sensitivity test take several days because time must be allowed for the bacteria to grow on the culture media However, infections are treated as soon as possible In a few instances, the primary health care provider may determine that a penicillin is the treatment of choice until the results of the culture and sensitivity tests are known. In many instances, the primary health care provider selects a broad-spectrum antibiotic (ie, an antibiotic that is effective against many types or strains of bacteria) for initial treatment because of the many penicillin-resistant strains of microorganisms. 

Imidazolidinyl urea kills gram-negative bacteria. It acts synergistically with parabens to provide a broad-spectrum antibiotic that is effective against mold, yeast, and bacteria. The combination of the two chemicals constitutes the most widely used preservative in cosmetics. 

Polypropionate chains with alternating methyl and hydroxy substituents are structural elements of many natural products with a broad spectrum of biological activities (e.g. antibiotic, antitumor). The anti-anti stereotriad is symmetric but is the most elusive one. Harada and Oku described the synthesis and the chemical desymmetrization of meso-polypropionates [152]. More recently, the problem of enantiotopic group differentiation was solved by enzymatic transesterification. The synthesis of the acid moiety of the marine polypropionate dolabriferol (Figure 6.58a) and the elaboration of the C(19)-C(27) segment of the antibiotic rifamycin S (Figure 6.58b) involved desymmetrization of meso-polypropionates [153,154]. 

When treating acne vulgaris, topical and systemic therapies (if indicated) are initiated 2 to 4 weeks prior to peeling. Topical antibiotics and benzoyl peroxide based products can be used daily and discontinued 1 or 2 days prior to peeling. However, unless a deeper peel is desired, retinoids should be discontinued 7-10 days prior to salicylic acid peeling. Broad-spectrum sunscreens (UVA and UVB) should be worn daily (see Photo damage. Sunscreen section). 

Acylation of 6-APA with appropriate substances results in new penicillins being produeed whieh differ only in the nature of the side chain (Table 5.1 Fig. 5.2). Some of these penieillins have considerable activity against Gram-negative as well as Grampositive baeteria, and are thus broad-spectrum antibiotics. Pharmacokinetic properties may also be altered. 

The olivanic acids (general structure, Fig. 5.5D) are naturally-occurring /3-lactam antibiotics which have, with some difficulty, been isolated from culture fluids of Strep, olivaceus. They are broad-spectrum antibiotics and are potent inhibitors of various types of/3-lactamases. 

Thienamycin (Fig. 5.5E) is a broad-spectrum /3-lactam antibiotic with high /3-lactamase resistance. Unfortunately, it is chemically unstable, although the TV-formimidoyl derivative, imipenem, overcomes this defect. Imipenem (Fig. 5.5E) is stable to most/3-lactamases but it readily hydrolysed by kidney dehydropeptidase and is administered with a dehydropeptidase inhibitor, cilastatin. Meropenem, which has yet to be marketed, is more stable than imipenem to this enzyme and may thus be administered without cilastatin. Its chemical structure is depicted in Fig. 5.5F. 

Schouten A, G van den Berg, C Edel-Hermann, C Steinberg, N Gautheron, C Alabouvette, CH de Vos, P Lemanceau, JM Raaijmakers (2004) Defense responses of Fusarium oxysporum to 2,4-diacetylphlo-roglucinol, a broad-spectrum antibiotic produced by Pseudomonas fluorescens. Mol Plant-Microbe Interact 17 1201-1211. 

A broad-spectrum antimicrobial target must be conserved across all pathogens of interest within a therapeutic product profile, essential for bacterial growth, and either absent, substantially different or non-essential in humans. PDF meets all of these criteria and is one of the most promising unexploited bacterial targets in the search for new antibiotics with a novel mode of action. 

If the presence of SBP is suspected, empiric antibiotic therapy with a broad-spectrum anti-infective agent should be initiated until cultures and susceptibilities are available (Fig. 19-5).45,46 In the setting of presumed infection, delaying... 

It is often difficult to narrow the spectrum of activity of the antibiotic choice since the infections are usually polymicrobial. As such, patients may receive long courses of broad-spectrum antibiotics such as imipenem/cilastatin and... 

Penicillins (amoxicillin, ampicillin) Broad-spectrum antibiotics may alter intestinal flora, Decrease efficacy of COCs, although the... 

Treat acute bacterial conjunctivitis with broad-spectrum antibiotics. Although the condition is usually self-limiting, antibiotic treatment decreases the spread of disease to other people and prevents extraocular infection. Additionally, treatment may help decrease the risk of corneal ulceration or other complications that affect sight. Finally, treatment speeds recovery.14... 

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