Treatment of Staphylococcus lugdunensis Infections
Treat S. lugdunensis infections aggressively with the same approach as S. aureus infections, using beta-lactam antibiotics based on susceptibility testing, because this organism causes substantially more virulent disease than other coagulase-negative staphylococci with high rates of perivalvular extension, metastatic infection, and mortality. 1
Key Clinical Recognition
S. lugdunensis is NOT a typical coagulase-negative staphylococcus—it behaves like S. aureus:
- When isolated from blood cultures, treat as a true pathogen rather than contamination 2
- This organism causes aggressive infections with valve destruction, abscess formation, and metastatic spread similar to S. aureus 1, 3
- Mortality and complication rates approach those of S. aureus endocarditis 1
- Requires species-level identification through specialized testing (pyrrolidonyl aminopeptidase hydrolysis, MALDI-TOF, or PCR) 1
Antibiotic Selection
First-line therapy: Beta-lactam antibiotics based on susceptibility
- Oxacillin-susceptible strains (majority): Use nafcillin, oxacillin, or cloxacillin at standard S. aureus dosing 1, 4
- Cefazolin is an acceptable alternative 5, 4
- S. lugdunensis remains highly susceptible to most antibiotics (86-96% oxacillin-susceptible) 6, 7, 3, 4
- Beta-lactam therapy shows superior outcomes compared to vancomycin (92% vs 76% treatment success at 2 years for prosthetic joint infections) 4
Avoid vancomycin as first-line therapy unless the patient has a severe beta-lactam allergy or the isolate is methicillin-resistant 5, 4
Treatment Duration by Clinical Scenario
Catheter-Related Bloodstream Infection (CRBSI)
- Manage identically to S. aureus CRBSI: Remove catheter and treat for 4-6 weeks 1, 8
- Do NOT use the short 5-7 day regimen appropriate for other coagulase-negative staphylococci 1, 8
- Obtain transesophageal echocardiography to exclude endocarditis 1
Infective Endocarditis
- Duration: 4-6 weeks of parenteral beta-lactam therapy 1
- Monitor closely for periannular extension and extracardiac spread 1
- High surgical intervention rate due to valve destruction and abscess formation 1, 3
- Do NOT add aminoglycosides—they increase renal toxicity without improving outcomes 5
Prosthetic Joint Infection
- Surgical approach: Two-stage revision achieves 85% cure rate versus 33% for other approaches 9
- Debridement alone or no surgery results in 44-100% relapse rates 9
- Antibiotic duration: Prolonged parenteral beta-lactam therapy (median 38 days in successful cases) 9, 4
- One-stage revision and antibiotic-only approaches have unacceptably high failure rates 9
Skin and Soft Tissue Infections
- Oral antibiotics effective for uncomplicated cases: amoxicillin-clavulanate, cefuroxime axetil, or doxycycline 6, 7
- Treatment duration: Standard course for skin infections (typically 7-14 days) 6, 7
- 100% cure rate reported with appropriate antibiotic therapy 6
- Common presentations: folliculitis, hidradenitis suppurativa, abscesses 6, 7
Critical Monitoring Requirements
All patients require:
- Transesophageal echocardiography to exclude endocarditis, even with apparent localized infection 1
- Serial blood cultures to document clearance 5
- Close surveillance for metastatic complications (vertebral osteomyelitis, epidural abscess, septic arthritis) 1, 3
Common Pitfalls to Avoid
- Do not dismiss as contaminant: Unlike other coagulase-negative staphylococci, S. lugdunensis in blood cultures represents true infection 2, 8
- Do not use short-course therapy: Even for catheter-related infections, treat for 4-6 weeks like S. aureus 1, 8
- Do not rely on vancomycin: Beta-lactams show superior outcomes 4
- Do not attempt conservative management of prosthetic joint infections: Two-stage revision is necessary for cure 9
- Do not skip echocardiography: The aggressive nature of this organism mandates cardiac imaging 1