What is the treatment for Cutibacterium avidum infections?

Treatment of Cutibacterium avidum Infections

For Cutibacterium avidum infections, beta-lactam antibiotics (such as penicillins or cephalosporins) are the preferred first-line agents, with surgical intervention required for implant-associated infections. 1, 2, 3

Antibiotic Selection

First-Line Therapy

• Beta-lactam antibiotics are the treatment of choice, including intravenous cefazolin or penicillin-based agents 1, 3
• For prosthetic joint infections, intravenous cefazolin (n=6 patients) or clindamycin (n=8 patients) were most commonly used as first-line agents 3
• The successful case of intraperitoneal abscess was treated with beta-lactam antibiotics combined with surgical drainage 1

Critical Resistance Considerations

• Avoid clindamycin as empiric therapy - high-level resistance is increasingly common, with 65.9% of strains showing clindamycin resistance 4
• The resistance gene erm(X) is present in 92.6% of clindamycin-resistant strains and appears to be widely disseminated 4
• Multidrug resistance is emerging: 34.1% of strains show ciprofloxacin resistance, with 13 of 14 also resistant to macrolides and clindamycin 4
• Susceptibility testing is mandatory before finalizing antibiotic selection, as resistance patterns are unpredictable 1, 4

Duration of Therapy

Implant-Associated Infections

• Total antibiotic duration: 12 weeks (median range 6-13 weeks) 3
• Intravenous therapy: 4 weeks (median range 2-6 weeks), followed by transition to oral agents 3
• This follows the general principle for implant-related infections requiring 6 weeks of therapy after hardware removal 5

Non-Implant Infections

• For soft tissue abscesses without implants, treatment duration should be guided by clinical response, typically several weeks 1

Surgical Management

Implant Removal is Essential

• All implant-associated C. avidum infections require device removal for cure 2, 3
• For prosthetic joint infections, one-stage exchange arthroplasty was used in 14 of 15 chronic cases 3
• Breast implant infection required complete implant removal to achieve cure 2
• Surgical drainage is necessary for abscesses, even without implants 1

Timing of Surgery

• Early postoperative infections can be managed with excision synovectomy while retaining the implant in select cases 3
• Late chronic infections (the majority of C. avidum cases) require definitive hardware removal 3

High-Risk Patient Populations

Obesity is the single most important risk factor, with all 15 prosthetic hip infections occurring exclusively in obese patients (median BMI 35 kg/m²) 3

Additional risk factors include:

• Hip arthroplasty via anterior surgical approach (13 of 15 cases) 3
• Primary hip arthroplasty rather than revision surgery 3
• Aesthetic surgery involving deep skin folds (gluteal implants, abdominoplasty, liposuction) 6
• Breast implant augmentation 2

Diagnostic Approach

Preoperative Joint Aspiration

• Joint aspiration is the key diagnostic tool - 14 of 15 preoperative aspirates yielded C. avidum in prosthetic joint infections 3
• Do not dismiss C. avidum as a contaminant when clinical signs of infection are present 2

Microbiological Identification

• Identification requires phenotypic methods, MALDI-TOF MS, or 16S rRNA gene sequencing 1
• C. avidum is a slow-growing anaerobic organism requiring prolonged culture incubation 3

Clinical Pitfalls to Avoid

1. Never assume C. avidum is a contaminant - it has recognized virulence factors and pathogenic behavior 2, 6
2. Do not use clindamycin empirically - resistance rates exceed 65% 4
3. Do not attempt medical management alone for implant infections - device removal is mandatory 2, 3
4. Recognize the association with obesity and anterior hip approaches - these patients warrant heightened surveillance 3
5. Ensure adequate culture duration - as a slow-growing anaerobe, standard culture times may miss this organism 3

Treatment Algorithm Summary

1. Obtain cultures via joint aspiration or tissue biopsy before antibiotics
2. Start empiric beta-lactam therapy (avoid clindamycin)
3. Plan surgical intervention - drainage for abscesses, implant removal for device-associated infections
4. Adjust antibiotics based on susceptibility testing results
5. Administer IV therapy for 2-4 weeks until clinically stable
6. Transition to oral therapy to complete 12 weeks total for implant infections
7. Follow for minimum 12 months after treatment completion 5