Is Pseudomonas fluorescens in breast milk susceptible to Augmentin (amoxicillin-clavulanate)?

Pseudomonas fluorescens in Breast Milk and Augmentin Susceptibility

Pseudomonas fluorescens in breast milk is not susceptible to Augmentin (amoxicillin-clavulanate) and alternative antibiotics should be used for treatment. 1

Understanding P. fluorescens and Augmentin

Pseudomonas fluorescens belongs to a complex of environmental and occasionally opportunistic pathogens that demonstrate intrinsic resistance to many antibiotics. The evidence specifically indicates that Pseudomonas species, including P. fluorescens, are typically resistant to Augmentin because:

• The beta-lactamases produced by Pseudomonas species are less susceptible to clavulanic acid (the beta-lactamase inhibitor in Augmentin) 1
• P. fluorescens has both intrinsic and acquired resistance mechanisms that limit effectiveness of many common antibiotics 2

Appropriate Antibiotic Options for P. fluorescens

When treating P. fluorescens in breast milk, consider the following options:

1. Colistin - Research demonstrates P. fluorescens sensitivity to colistin at low concentrations (0.076 μg/ml) 3
2. Aminoglycosides - Kanamycin shows high effectiveness against P. fluorescens (MIC 0.366 μg/ml) 3
3. Tetracycline - Effective against P. fluorescens (MIC 0.305 μg/ml) 3
4. Chloramphenicol - Shows good activity against P. fluorescens (MIC 0.732 μg/ml) 3

Treatment Algorithm for P. fluorescens in Breast Milk

1. First-line therapy: Colistin (most recent evidence shows highest effectiveness)
2. Alternative options:
   • Aminoglycosides (e.g., tobramycin)
   • Tetracycline (if not breastfeeding)
   • Chloramphenicol

Breastfeeding Considerations During Treatment

If the mother is breastfeeding, special considerations apply:

• Continue breastfeeding during antibiotic treatment when using breastfeeding-compatible antibiotics 4
• Aminoglycosides like tobramycin may be used while breastfeeding, as evidence shows minimal to no detection in breast milk 5
• Avoid tetracyclines during breastfeeding due to potential effects on infant development 4
• Monitor the infant for potential side effects such as diarrhea, rash, unusual fussiness, or lethargy 4

Important Clinical Caveats

1. Antibiotic combination therapy: Consider synergistic combinations of antibiotics with antimicrobial peptides for resistant strains 3
2. Diagnostic considerations: P. fluorescens can be differentiated from P. aeruginosa in milk-based media by pigment production patterns 6
3. Resistance monitoring: P. fluorescens may develop resistance during treatment, particularly to beta-lactam antibiotics 2
4. Breast health: Continue frequent and complete emptying of the affected breast during treatment 4

Conclusion

For P. fluorescens infections in breast milk, Augmentin is not an appropriate choice due to intrinsic resistance. Instead, use colistin as first-line therapy, with aminoglycosides as an alternative that remains compatible with continued breastfeeding.