Ceftobiprole Susceptibility Testing 

Ceftobiprole is a fifth-generation cephalosporin with broad-spectrum activity against both Gram-positive and Gram-negative bacteria. It is unique for its potent activity against methicillin-resistant Staphylococcus aureus (MRSA) due to its ability to bind to the altered penicillin-binding protein (PBP2a). It is approved for the treatment of complicated skin and soft tissue infections (cSSTIs) and community-acquired pneumonia (CAP). Susceptibility testing for ceftobiprole is essential to guide its appropriate use and monitor emerging resistance.

Content:

• Testing Methods:
  • Disk Diffusion (Kirby-Bauer Method):
    • Disks containing ceftobiprole (30 µg) are placed on Mueller-Hinton agar plates inoculated with the bacterial isolate.
    • After incubation, the diameter of the inhibition zone is measured and interpreted using EUCAST or CLSI guidelines.
  • Minimum Inhibitory Concentration (MIC) Testing:
    • MIC is determined using broth microdilution, agar dilution, or automated systems.
    • The MIC is the lowest concentration of ceftobiprole that inhibits visible bacterial growth.
• • Automated Systems:
    • Systems like Vitek or Phoenix may include ceftobiprole in their susceptibility panels, although validation for this agent may vary.

Application:

• Clinical Use:
  • Ceftobiprole is approved for:
    • Complicated skin and soft tissue infections (cSSTIs), including those caused by MRSA and susceptible Gram-negative pathogens.
    • Community-acquired pneumonia (CAP) caused by susceptible organisms, including Streptococcus pneumoniae.
    • Off-label use in treating healthcare-associated pneumonia (HAP) and multidrug-resistant Gram-positive infections.
• Antimicrobial Stewardship:
  • Promotes the targeted use of ceftobiprole in MRSA and other resistant infections to reduce reliance on glycopeptides (e.g., vancomycin) or other broad-spectrum agents.
• Epidemiological Surveillance:
  • Monitors resistance trends in MRSA, Streptococcus pneumoniae, and Pseudomonas aeruginosa.

Ceftobiprole susceptibility testing is essential for guiding therapy in infections caused by multidrug-resistant Gram-positive and Gram-negative bacteria, including MRSA and Pseudomonas aeruginosa. Standardized methods, such as MIC testing and disk diffusion, ensure reliable results.