Nationwide surveillance of resistance rates of Staphylococcus aureus clinical isolates from Greek hospitals, 2012–2013.

DRUG resistance in microorganisms; HOSPITALS; MEDICAL cooperation; RESEARCH; STAPHYLOCOCCUS aureus; STEROIDS; VANCOMYCIN; METHICILLIN-resistant staphylococcus aureus; DESCRIPTIVE statistics; IN vitro studies; LINEZOLID

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]