Where is Staphylococcus lugdunensis typically found on the human body?

Where Staphylococcus lugdunensis is Found

Staphylococcus lugdunensis is primarily found as normal skin flora in the groin, perineum, lower extremities, and especially the nail beds of the toes, with distinctly different colonization patterns compared to S. aureus. 1

Primary Colonization Sites on the Human Body

Lower Body Predominance

• The groin and perineal region are the most common colonization sites, with S. lugdunensis frequently isolated from these areas in healthy individuals 1, 2
• The nail bed of the first toe is a particularly common niche, yielding S. lugdunensis more frequently than other body sites 1
• Lower extremities overall serve as a primary reservoir for this organism 1

Less Common Sites

• The axilla can harbor S. lugdunensis, though less frequently than lower body sites 1
• Nasal colonization is rare, which distinguishes S. lugdunensis from S. aureus (which commonly colonizes the nose) 3, 1
• The breast and other upper body sites are less commonly colonized 1

Prevalence in Normal Flora

• In one study of 75 healthy subjects, S. lugdunensis was isolated from 50 individuals (67%), making it more prevalent than S. aureus in the overall skin flora 1
• This high colonization rate explains why it can cause skin and soft tissue infections, as it transitions from commensal to pathogen 4, 5

Clinical Significance of Colonization Patterns

Why Location Matters

• The predominant colonization of lower body sites explains why S. lugdunensis is an uncommon blood culture contaminant (unlike S. epidermidis which colonizes areas near common venipuncture sites) 1
• When S. lugdunensis is isolated from blood cultures, it should be taken seriously as a true pathogen rather than dismissed as contamination 3, 6

Infection Patterns Reflect Colonization

• Skin and soft tissue infections are the most common clinical manifestation (55.4% of cases), reflecting its role as skin flora 7
• The organism causes folliculitis, pustulosis, abscesses, and cellulitis, particularly on the back and digits 4, 5

Critical Distinction from Other Staphylococci

• Unlike S. aureus (which primarily colonizes the nose), S. lugdunensis colonizes the groin and lower extremities 1
• This distinct ecological niche is important for understanding transmission patterns and infection risk 1
• At least two independent blood culture sets are necessary to differentiate contamination from true infection when S. lugdunensis is isolated from blood 6