Antimicrobial activity spectrum

Tetracyclines are produced by various Streptomyces strains and are extensively applied in human and veterinary medicine. They display a broad spectrum of antimicrobial activity in combination with low toxicity and can be applied orally. The most commonly prescribed tetracycline drugs are tetracycline itself and oxytetracycline, an oxygenated derivative, which are directly isolated from fermentation liquors, and doxycycline whose partial synthesis from oxy-... 

Lomefloxacin, difluoroquinolone with wide spectrum of antimicrobial activity 98MI3. 

Widespread clinical acceptance continues to be accorded to the cephalosporins, and the field is extremely active as firms search for the ultimate contender. Among the characteristics desired is retention of the useful features of the older members (relatively broad spectrum, less antigenicity than the penicillins, relative insensitivity toward 3-lactamases, and convenience of administration) while adding better oral activity and broader antimicrobial activity (particularly potency against Pseudomonas, anaerobes, meningococci, cephalosporinase-carrying organisms, and the like). To a considerable extent these objectives have been met, but the price to the patient has been dramatically increased. 

The magaiitins are a class of hnear, cationic, faciaUy amphipathic and hehcal antibacterial peptides derived from frog skin [51]. The magaiitins exhibit highly selective and potent antimicrobial activity against a broad spectrum of organisms [52, 53]. As these peptides are faciaUy amphipathic, the magainins have a cationic heli-... 

Phenoxyethanol (2-phenoxyethanol). Typical in-use concentration 1%. It is more active against Ps. aeruginosa than against other bacteria and is usually combined with other preservatives such as the hydroxybenzoates to broaden the spectrum of antimicrobial activity. 

Hoover WW, Gerlach EH, Hoban DJ, Eliopou-los GM, Pfaller MA, Jones RN Antimicrobial activity and spectrum of rifaximin, a new topical rifamycin derivative. Diagn Microbiol Infect Dis 1993 16 111-118. 

Rifaximin is a synthetic rifamycin derivative, which acts by inhibiting bacterial ribonucleic acid (RNA) synthesis [48]. It is virtually unabsorbed after oral administration and is, therefore, used primarily to treat gastrointestinal infections. Rifaximin possesses a broad spectrum of antimicrobial activity, covering Gram-positive and Gram-negative bacteria, both arerobic and anaerobic [49], Several studies [44, 49-62] have shown that in patients with HE rifaximin displays an efficacy similar to that of lactulose and neomycin (table 1). A recently published study [62] compared the efficacy and safety of... 

Potential therapeutic applications of host defense peptides also include the lantibiotic nisin. Indeed, nisin has had an impressive history as a food preservative with FDA approval in 1988 for use in pasteurized, processed cheese spreads. The attractiveness of nisin as a potential therapeutic is also enhanced due to its relative resistance to proteases and broad spectrum Gram-positive antimicrobial activity including multidrug-resistant strains. Biosynexus Inc. has licensed the use of nisin for human clinical applications and Immucell Corp. has licensed the use of Mast Out, an antimastitic nisin-containing product, to Pfizer Animal Health." Indeed, nisin formulations have been used as an active agent in the topical therapies Mast Out and Wipe-Out for bovine mastitis, an inflammatory disorder of the udder that is the most persistent disease in dairy cows." ... 

Sader HS, Fedler KA, Rennie RP, Stevens S, Jones RN. (2004) Omiganan pentahydrochloride (MBI 226), a topical 12-amino-acid cationic peptide Spectrum of antimicrobial activity and measurements of bactericidal activity. Antimicrob Agents Chemother 48 3112-3118. 

The first completely synthetic monocyclic beta-lactam antibiotic was aztreonam. The antimicrobial activity of this drug is exhibited mainly with respect to a broad spectrum of aerobic Gram-negative bacteria. It is resistant to beta-lactamases and does not induce their formation. The mechanism of its action is identical to that of other beta-lactam antibiotics with respect to Gram-negative bacteria. PBP are inactivated in the presence of aztreonam. 

Chloramphenicol has a broad spectrum of antimicrobial activity, including Gram-positive, Gram-negative, aerobic, and anaerobic bacteria, spirochaeta, mycoplasma, chlamydia, and so on however, it can cause pronounced suppression of blood flow, which is accompanied by reticulocytopenia, granulocytopenia, and in severe cases, aplastic anemia. 

Sulfouamides have a broad spectrum of antimicrobial activity, including Staphylococcus aureus, nonenterococcal types of Streptococcus, Listeria monocytogenes, Nocardia, Neisseria, Haemophilius influenzae, enteric Gram-negative types of E. coli, Proteus mirabilis, and a few forms of anaerobic bacteria. Above all, sulfonamides are used for treating uncomplicated infections of the urinary tract, infections caused by Nocardia asteroids, streptococcal pharyngitis, menigococcal diseases, toxoplasmosis, and others. 

Sulfalene is also a very long-lasting bacteriostatic sulfanilamide with a broad spectrum of antimicrobial activity. It is used for the same indications as sulfadoxine. Its half-life is about 150-200 h. This drug binds to proteins in the plasma to a lesser degree than other sulfanilamides, which ensures its high concentration in the blood in a free form. Therefore, only one dose of sulfalene needs to be taken one time per week. Synonyms of this drug are celfizin, sulfamethopyrazine, sulfamethoxypyrazine, and others. 

Trimethoprim has a broad spectrum of antimicrobial activity. It is 20-100 times more active than sulfamethoxazole with respect to most bacterial forms. Trimethoprim is active with respect to Gram-positive, aerobic bacteria such as Staphylococcus aureus, Staphylococcus epidermidis, and various types of Streptococcus and Listeria monocytogenes. Trimethoprim is inferior to sulfonamides against forms of Nocardia. It is active... 

Triclosan is a broad-spectrum antimicrobial compound. It was originally used in soaps, antiperspirants, and cosmetic toiletries as a germicide. Today, triclosan is incorporated into toothpaste because of its wide spectrum of antimicrobial activities and low toxicity. 

The penicillins are a large group of bactericidal compounds. They can be subdivided and classified by their chemical structure and spectrum of activity. The structure common to all penicillins is a (3-lactam ring fused with a thiazolidine nucleus (Fig. 45.1).The antimicrobial activity of penicillin resides in the (3-lactam ring. Splitting of the (3-lactam ring by either acid hydrolysis or (3-lactamases results in the formation of penicilloic acid, a product without antibiotic activity. Addition of various side chains (R) to the basic penicillin molecule... 

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