Dalfopristin

About: Dalfopristin is a research topic. Over the lifetime, 696 publications have been published within this topic receiving 26621 citations. The topic is also known as: RP-54476 & Dalfopristina.

Mechanisms of action of newer antibiotics for Gram-positive pathogens.

Abstract: Summary Certain Gram-positive bacteria, including meticillin-resistant Staphylococcus aureus , vancomycin-resistant enterococci, and quinolone-resistant Streptococcus pneumoniae have achieved the status of "superbugs", in that there are few or no antibiotics available for therapy against these pathogens. Only a few classes of novel antibiotics have been introduced in the past 40 years, and all since 1999, including the streptogramin combination quinupristin/dalfopristin (Synercid), the oxazolidinone linezolid, and the lipopeptide daptomycin. This review discusses the mechanisms of antibiotic action against Gram-positive pathogens, and resistance counter-mechanisms developed by Gram-positive bacteria, with emphasis on the newer agents.

Antibiotic treatment of gram-positive bone and joint infections.

Abstract: Gram-positive organisms, particularly staphylococci and streptococci, are responsible for the majority of bone and joint infections. Treatment of these infections can be difficult, usually involving a prolonged course of antibiotics, often with surgical intervention. The selection of antibiotics depends on sensitivity profile, patient tolerance and long-term goals, e.g. cure or suppression, but there are few randomized con- trolled trials in patients comparing efficacy of different antibiotics. Different degrees of bone penetration and clinical outcome for specific antibiotics, e.g. the β-lactams, clindamycin and quinolones, have been described, although the methodology in these studies is not standardized and findings cannot always be applied directly to patients. The effect of attaining minimum serum bactericidal concentrations in patients has also been studied but this is no longer routinely recommended in clinical practice. Comparative clinical trials are few but have demonstrated efficacy of oral fluoroquinolones in combination with either rifampicin or fusidic acid for selected Gram-positive infections. In the past decade, increasingly resistant organisms, e.g. methicillin- resistant Staphylococcus aureus and vancomycin-resistant enterococci have been recognized as causes of orthopaedic infection. Individual case reports describe successful treatment using the newer antibiotics, e.g. linezolid and quinupristin/dalfopristin, but results of clinical trials are awaited.

Staphylococcus epidermidis: Emerging Resistance and Need for Alternative Agents

Abstract: Previously, Staphylococcus epidermidis and other coagulase-negative staphylococci isolated from the blood of hospitalized patients were often considered contaminants. Now, coagulase-negative staphylococci are among the leading causes of nosocomial blood infections. Multidrug resistance could predict a true nosocomial infection rather than a blood culture contaminant. Recent studies indicated the emergence of resistance to the quinolones, particularly to ciprofloxacin. Tolerance and occasional resistance to vancomycin have been reported recently. In addition, several reports indicated that vancomycin and other glycopeptide antibiotics lose their effectiveness against S. epidermidis organisms embedded in the biofilm environment on the surface of medical devices. Alternative agents have been proposed in the prevention and treatment of device-related and glycopeptide-tolerant S. epidermidis infections. These agents include minocycline, rifampin, and, more recently, quinupristin/dalfopristin and the oxazolidinones.

Increasing prevalence of antimicrobial resistance among isolates of Streptococcus pneumoniae from the PROTEKT surveillance study, and compatative in vitro activity of the ketolide, telithromycin

Abstract: The prevalence of resistance to a range of antimicrobials was determined for isolates of Streptococcus pneumoniae examined in the PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) surveillance study (1999-2000) using NCCLS testing methods and interpretative criteria. Of 3362 pneumococcal isolates collected from 69 centres in 25 countries, 22.1% overall were resistant to penicillin G, with the highest rates of resistance found among isolates from Asia (53.4%), France (46.2%) and Spain (42.1%). Erythromycin A resistance occurred in 31.1% of isolates overall with the highest rates found in Asia (79.6%), France (57.6%), Hungary (55.6%) and Italy (42.9%). Marked geographical differences in the prevalence of both penicillin G (the Netherlands 0%; South Korea 71.5%) and erythromycin A (Sweden 4.7%; South Korea 87.6%) resistance were observed. Asia was characterized by the highest prevalence of resistance, overall, with only eight of 19 antimicrobials (co-amoxiclav, linezolid, vancomycin, teicoplanin, quinupristin/dalfopristin, levofloxacin, moxifloxacin and telithromycin) retaining high activity against isolates of S. pneumoniae from this region. Notable rates of resistance to clarithromycin, azithromycin, co-trimoxazole and tetracycline were observed in the majority of countries submitting isolates of S. pneumoniae to the PROTEKT surveillance study. Fluoroquinolone resistance was low (1%), overall, although 14.3% of 70 isolates from Hong Kong were resistant to levofloxacin and moxifloxacin, all but one of these isolates belonging to a single clone of the 23F serotype. Although, at present, apparently limited to pockets of clonal spread, continued vigilance with regard to the evolution of fluoroquinolone resistance is indicated. Telithromycin (MIC(90) 0.12 mg/L; 99.9% of isolates susceptible) and lin- ezolid (MIC(90) 2 mg/L; 100% of isolates susceptible) were the two most active oral agents tested, both compounds retaining activity against isolates of fluoroquinolone-resistant S. pneumoniae. The results of the PROTEKT surveillance study 1999-2000 emphasize the widespread evolution of resistance to a variety of antimicrobials amongst isolates of S. pneumoniae and demonstrate the potential of telithromycin as a therapeutic option for the treatment of community-acquired respiratory tract infections caused by this organism.