Broad-spectrum activity

Norfloxacin (1, R = C2H5, R = H), a typical example, exhibits broad-spectrum activity and is useful in the treatment of upper respiratory tract and urinary infections [7] Lomefloxacin (2), a very recent introduction, is a third-generation product that, given once daily, is especially useful against pathogens resistant to cephalosponns, penicillins, and aminoglycosides [4] Floxacillin (J) is a stable, orally active antibacterial with improved activity over thenonfluonnated product (cloxacillin) [5]... 

Ampicillin is the standard penicillin that has broad-spectrum activity, and is the drug of choice for enterococci sensitive to penicillin. Amoxicillin is frequently used as well. Increasing E. coli resistance has limited amoxicillin use in acute cystitis. Amoxicillin-clavulanate is empirically preferred due to resistance. 

These agents have broad-spectrum activity, including gram-positive, gram-negative, and anaerobic bacteria. Imipenem and meropenem are active against P. aeruginosa and enterococci, but ertapenem is not. All may be associated with Candida superinfections. Rarely used for UTIs. 

These agents have broad-spectrum activity against both gram-negative and gram-positive bacteria. They provide high urine and tissue concentrations and are actively secreted in reduced renal function. Switch to oral when possible due to excellent bioavailability. 

Spectrum of activity A qualitative term that describes the number of different bacterial species that are susceptible to an antimicrobial regimen. Generally, broad-spectrum activity refers to regimens that possess activity against many bacterial species, whereas narrow-spectrum therapy refers to activity against a few bacterial species. 

Beyer, D., Kroll, H. P., Endermann, R., Schiller, G., Siegel, S., Bauser, M., Pohlmann, J., Brands, M., Ziegelbauer, K., Haebich, D., Eymann, C., and Brotz-Oesterhelt, H. (2004). New class of bacterial phenylalanyl-tRNA synthetase inhibitors with high potency and broad-spectrum activity. Antimicrob. Agents Chemother. 48, 525—532. 

The plant cell is a basic unit for germination, growth and development of plants. The allelochemicals first come in contact with the cell and then allelopathic interactions take place. Some allelochemicals have broad-spectrum activity that extends to the tissues of host plants, where their effects may be either beneficial or deleterious to plant germination, growth, development or yield. Hence, to understand the mechanisms of such intercations interactions the study of the cell and its various processes is very necessary. Therefore, this book has been been prepared (a) to make available all methods for such studies and (b) scientists can understand the scope of allelopathic research in relation to the cell. Hence, we have explained and discussed various techniques to study cell processes etc. 

Since the introduction of nalidixic acid in 1963, structural modifications on the quinolones have been performed to improve either the antibacterial efficacy or pharmacokinetic/toxicologic profiles of these compounds. The newest quinolones possess broad-spectrum activity, favorable pharmacokinetic/toxicologic profiles, and potency against bacterial strains that are resistant to older generations of quinolones. This section describes the synthetic procedures for the new generation of quinolones that were studied during the 1995-2005 period. 

A series of 7-diazabicycloalkyl quinolones has been prepared and found to exhibit excellent broad spectrum activity against important veterinary pathogenic bacteria [105], The structures of several of these interesting bicyclic analogues (76) as well as MIC data are summarized in Table 6.28. Compound (76e) (danofloxacin), which also exhibits excellent p.o. and s.c. activity in a mouse protection model for Pasteurella multocida [ 106], is undergoing development for use in veterinary medicine. It has been shown to exhibit excellent bioavailability properties in cattle, swine and poultry [107] and is efficacious in models for the treatment of respiratory diseases in food-producing animals [108],... 

It is recognized that as wood preservative systems that exhibit broad-spectrum activity are phased out, there will be an increase in the use of systems that are designed to be Tit for purpose . In the area of wood modification, it is well known that some systems perform well in some situations and less well in others. There will need to be a framework of tests that recognize this fact and allow products to be licensed that perform entirely satisfactorily in service, even though they may fail the current tests as they stand at the moment. 

Results from these laboratory studies demonstrated that avermectin Bj had high toxicity for the twospotted spider mite (Tetranychus urticae) on bean plants. When applied in solution directly onto adult and nymphal spider mite populations on foliage, avermectin Bj was shown to be 50-200 times as potent as commercially available acaricides, with an LC q of 0.02-0.03 ppm. Additional tests on foliage with insects in the order Lepidoptera, Coleoptera, Homoptera, Orthoptera, Diptera, Isoptera and Hymenoptera confirmed the broad spectrum activity and potency of the avermectin family of compounds and avermectin Bj in particular. Table II provides LC q values for avermectin Bj for the control of larval forms of several of these insects in foliar residue assays (18). 

Carbosulfan, CGA-73,102, and ONCOL are derivatives of carbofuran (2,3-dihydr0-2,2-dimethylbenzofuran-7-yl methylcarbamate) which have broad spectrum activity similar to that of carbofuran but are substantially less toxic to mammals. CGA-73,102 is particularly effective as a soil insecticide by both contact and systemic action (9). Thiodicarb (10) and U-56,299 (11) are highly effective lepidopterous larvicides but are less toxic to plants and mammals than me thorny 1. U-56,299, with a rat acute... 

Bnilding on the fonndation of these stndies, Haddad et al. used rings I and II of paromomycin (called paromomine) as the minimum structural motif in a computational search of over 273,000 componnds that might bind an A-site template. Results of this search were then narrowed based on steric and energetic demands. Several componnds were snbseqnently synthesized and shown to bind to an RNA model of the A-site, with some of the compounds (e.g., 2) exhibiting broad-spectrum activity in bacteria. X-ray strnctnres with the RNA models and with the 30S ribosome vindicated the design principles. The compounds do bind to the A-site and they do flip the two bases mentioned previously to the extrahelical position, as do other antibiotics of this class. 

Trimethoprim exhibits broad-spectrum activity. It is most commonly used in combination with sulfamethoxazole and is active against most gram-positive and gramnegative organisms, especially the Enterobacteriaceae. There is little activity against anaerobic bacteria P. aeruginosa, enterococci, and methiciUin-resistant staphylococci should be considered resistant to trimethoprim. 

Table V. Broad-Spectrum Activity Among LAB and Eukaryotic Peptides Peptide Organism Peptide Organism...

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