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PurposeTo evaluate thein vitroefficacy of several anti-staphylococcal agents against a nationwide collection of contemporaryStaphylococcus aureusclinical isolates from several healthcare centres in Greece.MethodsThirty hospitals throughout Greece (18 in Attica) provided all clinical isolates ofS.aureusfrom April 2012 to May 2013 to a central lab to be re-submitted to susceptibility testing. The MICs were evaluated by Vitek® 2 with the exception of ceftaroline (OXOID M.I.C. Evaluator™). Vancomycin and daptomycin MICs were also evaluated by Etest®. Heterogeneously vancomycin-intermediate strains (hVISA) were detected by the Etest® GRD. VISA phenotype was confirmed by PAP-AUC.ResultsA total of 1005 isolates (39% MRSA) were studied. Susceptibility rates were: erythromycin 66.5%, clindamycin 79.2%, SXT 98.9%, rifampicin 97.3%, fusidic acid 67%, moxifloxacin 78.8%, vancomycin 99.9%, ceftaroline 92.9% and linezolid, tigecycline and daptomycin 100%. For mupirocin, high level resistance could be excluded for 98.9% of isolates. Vancomycin Etest® MIC50/90were 1.5/1.5 mg/L, 58.5% of isolates exhibited a MIC > 1 and 8.7% a MIC of 2 mg/L, while Vitek® MIC50/90were 1/1 and 3.1% showed MIC > 1 mg/L. One VISA strain was detected. Among the selected 175 isolates that were screened for hVISA phenotype, six (3.4%) were positive. In 315 bloodstream isolates, 64.1% had a vancomycin Etest® MIC > 1 mg/L.ConclusionsThis multi-centre surveillance study revealed that a significant percentage of contemporaryS.aureusisolates from Greek patients have a vancomycin MIC (> 1 mg/L) that may compromise the clinical efficacy of the drug for the treatment of serious infections. Thein vitroactivity of SXT, rifampicin, mupirocin, linezolid, tigecycline, daptomycin and ceftaroline remains excellent. [ABSTRACT FROM PUBLISHER]

Abstract: A total of 10420 Gram-positive cocci (including staphylococci, enterococci and various groups of streptococci) collected from clinically significant specimens in ten Greek hospitals during 2006–2007 were tested for their susceptibility to daptomycin. The minimum inhibitory concentration (MIC) was determined by the broth microdilution method. Daptomycin demonstrated very high activity against Enterococcus faecalis (MIC at which 50% of the isolates were inhibited (MIC50)=1mg/L and MIC at which 90% of the isolates were inhibited (MIC90)=1.36mg/L), Enterococcus faecium (MIC50 =1.36mg/L and MIC90 =1.90mg/L), Streptococcus pyogenes (MIC50 =0.12mg/L and MIC90 =0.50mg/L), Streptococcus agalactiae (MIC50 =0.09mg/L and MIC90 =0.12mg/L), Streptococcus pneumoniae (MIC50 =0.24mg/L and MIC90 =0.5mg/L) and viridans group streptococci (MIC50 =0.50mg/L and MIC90 =0.89mg/L). Resistance to linezolid and vancomycin for enterococci and to penicillin for streptococci appears to be independent of reduced susceptibility to daptomycin. On the other hand, daptomycin was also active against meticillin-resistant Staphylococcus aureus (MIC50 =0.44mg/L and MIC90 =0.78mg/L) and meticillin-resistant coagulase-negative staphylococci (MIC50 =0.24mg/L and MIC90 =0.44mg/L); however, 0.9% of the staphylococci tested had an MIC>1mg/L, which is the Clinical and Laboratory Standards Institute breakpoint proposed for susceptibility. For all tested organism groups, resistance to daptomycin was not associated with glycopeptide resistance. [Copyright &y& Elsevier]

Introduction. Dalbavancin was approved in Europe in 2015 for skin and soft tissue infections. Hypothesis/Gap Statement. Data on methicillin-resistant coagulase-negative staphylococci (MR-CNS) dalbavancin susceptibility are scarce. Aim. To assess the susceptibility of MR-CNS to dalbavancin and other anti-staphylococcal agents. Methodology. A total of 443 MR-CNS clinical isolates from patients hospitalized in a Greek university hospital during a 2.5-year period (January 2018 to June 2020) were included. The MICs for vancomycin, teicoplanin, linezolid and daptomycin were investigated by Etest and the MIC for dalbavancin was determined according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines in 196 isolates. The consumption of the aforementioned antimicrobials was calculated. Results. In total, 51 isolates were resistant to teicoplanin (11.5 %) and 211 (47.6 %) to linezolid; all were susceptible to vancomycin and daptomycin. Among 196 isolates tested, 32 (16.3 %) were resistant to dalbavancin. A significant increase of MIC during the study period was found for vancomycin, teicoplanin and daptomycin, while a decrease in linezolid's MIC was observed. Dalbavancin's MIC remained stable. No difference in consumption was observed among the studied anti-staphylococcal agents. Conclusion. An increase of vancomycin, teicoplanin and daptomycin MICs among MR-CNS was observed, whereas 47.6 % of isolates were non-susceptible to linezolid. Dalbavancin retains excellent potency against MR-CNS, even in the presence of non-susceptibility to other anti-staphylococcal antibiotics.