Treatment of Corynebacterium Infections
Vancomycin is the first-line treatment for invasive Corynebacterium infections due to its 100% susceptibility rate and proven clinical efficacy. 1
Antibiotic Selection Based on Infection Type
Invasive/Severe Infections
First-line:
Alternatives for severe infections:
- Linezolid
- Teicoplanin
- Daptomycin 1
Non-Severe/Mild Infections
- First-line options:
Diphtheria (C. diphtheriae)
- Erythromycin is specifically indicated for infections due to C. diphtheriae, as an adjunct to antitoxin, to prevent establishment of carriers and to eradicate the organism in carriers 2
- Penicillin is also considered a first-line option 3
Erythrasma (C. minutissimum)
- Erythromycin is indicated for infections due to C. minutissimum 2
Antimicrobial Susceptibility Considerations
Highly Effective Antibiotics (>90% susceptibility)
- Vancomycin (100% susceptibility) 4, 1
- Linezolid 1
- Teicoplanin 1
- Piperacillin-tazobactam 1
- Amoxicillin-clavulanate 1
- Doxycycline 4
- Fusidic acid 4
Variable or Limited Efficacy
- Erythromycin: 4% of C. diphtheriae and 2% of C. ulcerans show resistance 3
- Beta-lactams: Resistance is common in some species like C. xerosis and C. minutissimum 4
- Clindamycin: Resistance common in some species 4
- Fluoroquinolones: High degree of resistance reported 1
- Aminoglycosides: Resistance common in some species 4
- Macrolides: Resistance common in some species 1
Combination Therapy Considerations
- Vancomycin + piperacillin-tazobactam: Recommended for severe infections 1
- Erythromycin + rifampicin: Shows synergistic effects 5
- Erythromycin + penicillin: Shows synergistic effects 5
- Penicillin + gentamicin: Shows synergistic effects 5
Combinations to Avoid
- Gentamicin + erythromycin: Shows antagonistic effects 5
- Gentamicin + rifampicin: Shows antagonistic effects 5
Special Considerations
Diagnostic Testing
- Antimicrobial susceptibility testing is essential before treatment initiation due to variable resistance patterns 4
- Gene sequencing methods should be the gold standard for identification of Corynebacterium species, while MALDI-TOF and Vitek systems can be used as alternatives 1
Treatment Monitoring
- Despite appropriate antibiotic treatment, fatal outcomes were reported in approximately 20% of invasive infections 1
- For C. diphtheriae infections, monitoring for toxin-related complications is essential
Common Pitfalls to Avoid
Failure to obtain susceptibility testing: Antimicrobial susceptibilities of Corynebacterium species are unpredictable, making susceptibility tests necessary for selecting optimal treatment 4
Relying on disk diffusion methods alone: Discrepancies between disk diffusion and microdilution methods have been observed, particularly for penicillin susceptibility testing 6
Assuming all Corynebacterium species have similar susceptibility patterns: Significant variations exist between species, with C. jeikeium and C. urealyticum being the most resistant organisms 4
Overlooking the need for toxin neutralization in diphtheria: Antitoxin administration is crucial in addition to antimicrobial therapy for toxigenic C. diphtheriae 2
Using fluoroquinolones empirically: High resistance rates have been reported 1
By following these evidence-based recommendations and considering the specific Corynebacterium species and infection severity, clinicians can optimize treatment outcomes while minimizing the risk of treatment failure due to antimicrobial resistance.