In vitro activity of ceftaroline tested against isolates from the Asia-Pacific region and South Africa (2011)

Abstract

During 2011, 29 medical centres in eight Asia-Pacific countries and South Africa submitted a total of 3697 bacterial pathogens for surveillance testing, of which 39.1% were from respiratory tract, 27.9% from skin and skin-structure, 19.2% from bloodstream, 5.1% from urinary tract and 8.7% from miscellaneous infection types. Meticillin-resistant Staphylococcus aureus (MRSA) constituted 38.9% of the 1114 S. aureus. The MRSA rate was 53.5% for respiratory tract infections and 31.8% for skin and skin-structure infections. A total of 86.5% of S. aureus exhibited ceftaroline minimum inhibitory concentrations (MICs) at ≤1μg/mL. Ceftaroline (MIC₉₀, 0.25μg/mL) was eight-fold more active than ceftriaxone (MIC₉₀, 2μg/mL) against Streptococcus pneumoniae; erythromycin and clindamycin susceptibility were severely compromised. Against β-haemolytic streptococci, ceftaroline and other β-lactams were highly active, with MIC₉₀ values at 0.03μg/mL. The extended-spectrum β-lactamase (ESBL) phenotype rate was 57.6% among Escherichia coli, 49.7% among Klebsiella pneumoniae and 23.7% among Klebsiella oxytoca. ESBL phenotype rates for E. coli ranged from a low of 8.3% in South Africa to a high of 77.9% in India. For K. pneumoniae, the ESBL phenotype rate ranged from 20.6% in Australia to 67.8% in India. Ceftaroline was active against non-ESBL-phenotype E. coli and K. pneumoniae (MIC₉₀, 0.25μg/mL) but was not active against ESBL-phenotype strains (MIC₉₀, >32μg/mL). Overall, ceftaroline demonstrated in vitro activity against pathogens isolated from various infection sites, including respiratory tract, bloodstream, and skin and skin-structure infections, across the monitored nations.

Keywords: Meticillin-resistant Staphylococcus aureus; Streptococcus pneumoniae; Surveillance.