Evaluating the antibacterial activity of ceftaroline against clinical isolates of methicillin-susceptible and- resistant Staphylococcus aureus in Kuwait hospitals

Abstract

Ceftaroline fosamil has been approved by the US Food and Drug Administration for the treatment of skin and soft tissue infections, including those caused by methicillin-resistant Staphylococcus aureus and community-acquired bacterial pneumonia. We evaluated the in-vitro activity of not-in-use ceftaroline against clinical isolates of methicillin- resistant (MRSA) and methicillin-susceptible (MSSA) S. aureus isolates. A total of 453 single-patient S. aureus isolates were tested for susceptibility to ceftaroline. The minimum inhibitory concentration (MIC) was determined using the MIC Evaluator. Disk diffusion test was performed using 30 μg ceftaroline disk according to the Clinical Laboratory Standards Institute criteria. In total, 410 (90.5%) of the 453 strains were susceptible to ceftaroline at MIC of 1 mg/L while 9.8% isolates had MIC of 2-3 mg/L. Among the MSSA, 92.5% of the isolates were susceptible with MIC: 1 mg/L while 36 (7.9%) strains expressed intermediate resistance (MIC range of 2-3 mg/L). None of the strains was resistant (MIC: 4 mg/L). Ceftaroline showed good in-vitro activity against MSSA and MRSA which can serve as an effective alternative to vancomycin in treating infections caused by MRSA.

Keywords: Ceftaroline; Methicillin-resistant S. aureus (MRSA); S. aureus.