From the Guidelines
Ceftriaxone is the preferred choice for treating Pasteurella multocida infections, while azithromycin is not recommended due to its poor activity against this organism. According to the most recent guidelines 1, ceftriaxone is effective against Pasteurella species and is typically dosed at 1g IV every 12 hours. Pasteurella multocida is highly susceptible to beta-lactam antibiotics, including ceftriaxone, which inhibits bacterial cell wall synthesis. Azithromycin, a macrolide antibiotic, does not reliably cover Pasteurella and should not be used as monotherapy for these infections.
Key Points to Consider
- The guidelines recommend ceftriaxone as a third-generation cephalosporin option for animal bites, which are commonly associated with Pasteurella multocida infections 1.
- Azithromycin is not listed as a recommended option for Pasteurella multocida infections in the guidelines, suggesting its poor activity against this organism.
- Other options like amoxicillin-clavulanate may be considered for less severe infections, but ceftriaxone is preferred for more serious infections requiring parenteral therapy.
- Prompt initiation of appropriate antibiotics is essential for treating suspected Pasteurella infections, as they can progress rapidly, particularly in immunocompromised patients.
Treatment Considerations
- Ceftriaxone dosing: 1g IV every 12 hours, depending on infection severity.
- Alternative options: amoxicillin-clavulanate for less severe infections, but ceftriaxone is preferred for more serious infections.
- Azithromycin is not recommended due to its poor activity against Pasteurella multocida.
From the Research
Antibiotic Coverage for Pasteurella multocida
- Azithromycin: The in vitro activity of azithromycin against Pasteurella multocida has been studied, with an MIC90 of 1.0 microgram/mL 2. Another study found that 90.5% of Pasteurella isolates showed intermediate susceptibility to azithromycin 3.
- Ceftriaxone: Ceftriaxone has been shown to have excellent in vitro activity against Pasteurella multocida, with an MIC of less than or equal to 0.098 4. It is a third-generation cephalosporin with a broad spectrum of activity against Gram-positive and Gram-negative bacteria 5.
Susceptibility of Pasteurella multocida to Antibiotics
- Pasteurella multocida isolates are generally susceptible to most widely used commercial antimicrobial agents, but resistance to certain antibiotics such as sulphonamides, tetracyclines, and aminoglycosides has been reported 6.
- The majority of Pasteurella multocida strains are susceptible to penicillin, macrolides, fluoroquinolones, and cephalosporins 2, 6, 3.
Alternative Therapeutic Options
- Trimethoprim-sulfamethoxazole and ciprofloxacin could be proposed as therapeutic alternatives in case of pasteurellosis following animal bites 3.
- Ceftriaxone may be an effective option for the treatment of serious infections due to multidrug-resistant Gram-negative bacteria, including Pasteurella multocida 5.