Cefpodoxime Susceptibility Testing 

Cefpodoxime is an oral third-generation cephalosporin antibiotic with activity against a broad spectrum of Gram-positive and Gram-negative bacteria. It is commonly used for treating respiratory tract infections, urinary tract infections (UTIs), and uncomplicated skin infections. Susceptibility testing for cefpodoxime is essential to guide its appropriate use, especially due to the rising prevalence of beta-lactamase-mediated resistance in Enterobacterales and other pathogens.

Content:

• Testing Methods:
  • Disk Diffusion (Kirby-Bauer Method):
    • Disks containing cefpodoxime (10 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 CLSI or EUCAST guidelines.
  • Minimum Inhibitory Concentration (MIC) Testing:
    • MIC is determined using broth microdilution, agar dilution, or automated systems.
    • The MIC is the lowest concentration of cefpodoxime that inhibits visible bacterial growth.
• • Automated Systems:
    • Platforms like Vitek, Phoenix, or MicroScan may include cefpodoxime in their susceptibility testing panels.

Application:

• Clinical Use:
  • Cefpodoxime is used for:
    • Respiratory tract infections: e.g., sinusitis, bronchitis, community-acquired pneumonia.
    • Uncomplicated urinary tract infections (UTIs) caused by susceptible E. coli or Klebsiella pneumoniae.
    • Uncomplicated skin and soft tissue infections.
    • Otitis media and pharyngitis caused by Streptococcus pyogenes or Haemophilus influenzae.
• Antimicrobial Stewardship:
  • Promotes the targeted use of cefpodoxime, reducing reliance on broader-spectrum antibiotics.
  • Avoids inappropriate use in resistant infections, preserving its efficacy.
• Epidemiological Surveillance:
  • Tracks resistance trends in Enterobacterales and Streptococcus pneumoniae.
  • Monitors the prevalence of ESBL-producing and AmpC-producing organisms.

Cefpodoxime susceptibility testing is crucial for guiding therapy against infections caused by Gram-positive and Gram-negative bacteria. Standardized methods, including MIC testing and disk diffusion, provide reliable results.