In vitro activity of ceftaroline against bacterial pathogens isolated from skin and soft tissue infections in Europe, Russia and Turkey in 2012: results from the Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) surveillance programme

Objectives: The objective of this study was to analyse antimicrobial susceptibility testing data generated by the Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) global surveillance programme for pathogens causing skin and soft tissue infections (SSTIs) in European countries in 2012.

Methods: Confirmation of pathogen identity by MALDI-TOF and antimicrobial susceptibility testing following the CLSI broth microdilution method were performed by a central laboratory.

Results: Using CLSI breakpoint criteria, ceftaroline was active against MSSA (n = 1116; MIC90, 0.25 mg/L; 99.8% susceptible), MRSA (n = 1467; MIC90, 1 mg/L; 92.2% susceptible) and Streptococcus pyogenes (n = 312; MIC90, 0.008 mg/L; 100% susceptible). By CLSI interpretative criteria, two S. aureus isolates (2/2583, 0.08%) were ceftaroline resistant (MIC, ≥4 mg/L) and 114 isolates (114/2583, 4.4%) were ceftaroline intermediate (2 mg/L). By EUCAST interpretative criteria (MIC, >1 mg/L), 4.5% (116/2583) of S. aureus isolates were ceftaroline resistant. Most ceftaroline-non-susceptible isolates (81.0%, 94/116) were from Russia, Turkey, Italy and Hungary. Ceftaroline susceptibility was equal to or exceeded 99% for S. aureus isolates submitted by 7 of 17 countries. Against Escherichia coli (n = 349), Klebsiella pneumoniae (n = 215), Klebsiella oxytoca (n = 74) and Proteus mirabilis (n = 121), ceftaroline activity was dependent upon ESBL production. For ESBL-negative E. coli, K. pneumoniae, K. oxytoca and P. mirabilis, 87.5% (MIC90, 1 mg/L), 92.3% (MIC90, 0.5 mg/L), 93.2% (MIC90, 0.5 mg/L) and 85.1% (MIC90, 2 mg/L) of isolates were susceptible to ceftaroline, respectively.

Conclusions: Ceftaroline demonstrated potent in vitro activity against a contemporary collection of bacterial pathogens from patients with SSTIs in European countries, Russia and Turkey. Surveillance programmes such as AWARE are essential to global efforts to improve antimicrobial stewardship.