Dalbavancin and Selected Comparison Agents Tested Against Indicated Gram-positive Isolates in European Medical Centers (Italy): Results from the DECIDE Program

tetracycline (96.4%) and gentamicin (99.3%). Staphylococci included MRSA (35.7%) and MR-CoNS (68.4%); and MRSA isolates were resistant to levofloxacin (96%) and erythromycin (74%). All clindamycin-susceptible SA had inducible resistance. Dalbavancin (MIC90; 0.047mg/L) was 10-fold more potent than vancomycin (MIC90; 0.5mg/L) against BHS. Erythromycin susceptibility was 82% with a 25% inducible clindamycin resistance. Conclusions: The DECIDE study demonstrated in UK and Ireland that dalbavancin has excellent activity and was more potent when directly compared to vancomycin. Dalbavancin was active against all MRSA, although the current susceptibility profiles for other antimicrobial classes tested were of great concern, particularly inducible clindamycin resistance (100%). Monitoring dalbavancin activity should be continued as this newer long-acting agent is introduced into EU clinical practice

Detecting imipenem resistance in Acinetobacter baumannii by automated systems (BD Phoenix, Microscan WalkAway, Vitek 2); high error rates with Microscan WalkAway

<p>Abstract</p> <p>Background</p> <p>Increasing reports of carbapenem resistant <it>Acinetobacter baumannii </it>infections are of serious concern. Reliable susceptibility testing results remains a critical issue for the clinical outcome. Automated systems are increasingly used for species identification and susceptibility testing. This study was organized to evaluate the accuracies of three widely used automated susceptibility testing methods for testing the imipenem susceptibilities of <it>A. baumannii </it>isolates, by comparing to the validated test methods.</p> <p>Methods</p> <p>Selected 112 clinical isolates of <it>A. baumanii </it>collected between January 2003 and May 2006 were tested to confirm imipenem susceptibility results. Strains were tested against imipenem by the reference broth microdilution (BMD), disk diffusion (DD), Etest, BD Phoenix, MicroScan WalkAway and Vitek 2 automated systems. Data were analysed by comparing the results from each test method to those produced by the reference BMD test.</p> <p>Results</p> <p>MicroScan performed true identification of all <it>A. baumannii </it>strains while Vitek 2 unidentified one strain, Phoenix unidentified two strains and misidentified two strains. Eighty seven of the strains (78%) were resistant to imipenem by BMD. Etest, Vitek 2 and BD Phoenix produced acceptable error rates when tested against imipenem. Etest showed the best performance with only two minor errors (1.8%). Vitek 2 produced eight minor errors(7.2%). BD Phoenix produced three major errors (2.8%). DD produced two very major errors (1.8%) (slightly higher (0.3%) than the acceptable limit) and three major errors (2.7%). MicroScan showed the worst performance in susceptibility testing with unacceptable error rates; 28 very major (25%) and 50 minor errors (44.6%).</p> <p>Conclusion</p> <p>Reporting errors for <it>A. baumannii </it>against imipenem do exist in susceptibility testing systems. We suggest clinical laboratories using MicroScan system for routine use should consider using a second, independent antimicrobial susceptibility testing method to validate imipenem susceptibility. Etest, whereever available, may be used as an easy method to confirm imipenem susceptibility.</p

Daptomycin antimicrobial activity tested against methicillin-resistant staphylococci and vancomycin-resistant enterococci isolated in European medical centers (2005)

BACKGROUND: Daptomycin is a cyclic lipopeptide with potent activity and broad spectrum against Gram-positive bacteria currently used for the treatment of complicated skin and skin structure infections and bacteremia, including right sided endocarditis. We evaluated the in vitro activity of this compound and selected comparator agents tested against clinical strains of staphylococci and enterococci collected in European medical centers in 2005. METHODS: A total of 4,640 strains from 23 medical centers located in 10 European countries, Turkey and Israel (SENTRY Program platform) were tested for susceptibility by reference broth microdilution methods according to Clinical and Laboratory Standards Institute guidelines and interpretative criteria. Mueller-Hinton broth was supplemented to 50 mg/L Ca(++ )for testing daptomycin. Results for oxacillin (methicillin)-resistant staphylococci and vancomycin-resistant enterococci were analyzed separately. RESULTS: Oxacillin resistance rates among Staphylococcus aureus varied from 2.1% in Sweden to 42.5% in the United Kingdom (UK) and 54.7% in Ireland (29.1% overall), while vancomycin resistance rates varied from 0.0% in France, Sweden and Switzerland to 66.7% in the UK and 71.4% in Ireland among Enterococcus faecium (17.9% overall). All S. aureus strains were inhibited at daptomycin MIC of 1 mg/L (MIC(50/90), 0.25/0.5 mg/L; 100.0% susceptible) and only one coagulase-negative staphylococci strain (0.1%) showed an elevated (>1 mg/L) daptomycin MIC value (4 mg/L). Among E. faecalis (MIC(50/90), 0.5/1 mg/L; 100% susceptible) the highest daptomycin MIC value was 2 mg/L; while among E. faecium (MIC(50/90), 2/4 mg/L; 100% susceptible) the highest MIC result was 4 mg/L. CONCLUSION: Daptomycin showed excellent in vitro activity against staphylococci and enterococci collected in European medical centers in 2005 and resistance to oxacillin, vancomycin or quinupristin/dalfopristin did not compromise its activity overall against these pathogens. Based on these results and those of previous publications, daptomycin appears to be an excellent therapeutic option for serious infections caused by oxacillin-resistant staphylococci and vancomycin-resistant enterococci in Europe

Optimization of the formulation of a phase change slurry

Based on a formulation for a Phase Change Slurry (PCS) with 30 wt.% n-octadecane, 7 wt.% emulsifier with an Hydrophilic-Lypophilic-Balance (HLB) of 12 and a nucleating agent an optimization of the composition of the PCS was done. The HLB and the emulsifier concentration as well as the phase change material (PCM)-fraction were modified. An improvement was checked on the basis of the particle size distribution, the viscosity and the phase change behaviour in the differential scanning calorimeter (DSC). To proof thermal-mechanical stability of the emulsion it is cycled in the rheometer over its phase change at a shear stress of 100 1·s-1. By changing the emulsifier concentration and the HLB of the emulsifiers it was possible to formulate PCSs showing low viscosities when cycling it over the phase change region. With the optimized formulation PCM-fractions of up to 45 wt.% of PCM were emulsified resulting in thermally-mechanically stable PCSs

The role of dalbavancin in the multi-disciplinary management of wound infections in orthopaedic surgery

Antimicrobial resistance is continuously increasing among bacterial clinical isolates (especially methicillin resistance in Staphylococcus aureus, MRSA), negatively impacting on outcomes of patients with Surgical Site Infections (SSIs). A multi-disciplinary team work is essential for SSIs prevention and for the choice of antibiotic therapy of orthopaedic SSIs. In particular, an Antibiotic Stewardship (AS) approach is recommended for preserving the activity of old and new antimicrobials. Dalbavancin is a novel antimicrobial agent, belonging to the lipoglycopeptides family, recently approved by FDA for the treatment of ABSSSIs (Acute Bacterial Skin and Skin Structure Infections) and can be considered as a candidate for the treatment of orthopaedic superficial SSIs. An antimicrobial activity directed against MRSA and other multi-resistant Gram-positive pathogens, a bactericidal effect and an extremely extended half-life are among key features of this drug. Dalbavancin gives to clinicians the option to provid..