The antimicrobial activity of ceftobiprole against Methicillin-resistant Staphylococcus aureus and multi-drug resistant Pseudomonas aeruginosa : A large tertiary care university hospital experience in Riyadh, Saudi Arabia

OBJECTIVES: To assess the antibacterial activity of ceftobiprole against Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) from various body specimen types and different patterns of resistance. METHODS: A retrospective cohort study with a total of 49 MRSA and 99 P. aeruginosa isolated in the Microbiology Laboratory at King Saud University Medical City, Riyadh, Saudi Arabia, between 2018-2019, were used. Isolates were randomly selected from various specimen types. The minimum inhibition concentration (MIC) of ceftobiprole was determined by E-test. Breakpoints carried out by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) were used to assess antibiotic susceptibility. RESULTS: Approximately 100% of the MRSA isolates were susceptible with MIC50/90 value of 1/1.5 mg/L while 69.8% of multi-drug resistant (MDR) P. aeruginosa isolates were resistant with MIC50/90 value of 16/32 mg/L. CONCLUSION: The excellent activity of ceftobiprole against MRSA would have major implications in management of the patients with serious infections, as an empirical treatment or alternative to vancomycin. Ceftobiprole has a very low activity against MDR P. aeruginosa, and its susceptibility should be tested prior to use for treatment.