Staphylococcus lugdunensis in several niches of the normal skin flora

Area of Science:

• Microbiology
• Dermatology
• Infectious Diseases

Background:

• Staphylococcus lugdunensis, a coagulase-negative staphylococcus (CNS), exhibits pathogenicity and virulence comparable to Staphylococcus aureus.
• S. lugdunensis is associated with severe infections like endocarditis and prolonged skin/soft-tissue infections, yet its normal habitat remains poorly understood.
• Its infrequent detection in blood cultures raises questions about its role as an integral part of the normal skin flora.

Purpose of the Study:

• To determine if S. lugdunensis is a part of the normal skin flora.
• To compare the ecological niches of S. lugdunensis and S. aureus on human skin.

Main Methods:

• Collected 525 swabs from multiple body sites (nose, axilla, perineum, groin, breast, toe, nail bed) of 75 healthy subjects.
• Cultured and identified S. lugdunensis and S. aureus from collected samples.
• Analyzed the distribution and prevalence of both bacterial species across different skin niches.

Main Results:

• S. lugdunensis was isolated from significantly more subjects (50/75) and samples (525) than S. aureus (16/75).
• S. aureus was frequently found in nasal swabs, whereas S. lugdunensis was rare in the nose.
• S. lugdunensis predominantly colonized the groin and lower extremities, particularly the first toenail bed, while S. aureus was less common in these areas.

Conclusions:

• Staphylococcus lugdunensis is an integral component of the normal human skin microbiota.
• Its primary colonization sites are the lower abdomen and extremities, differing significantly from S. aureus niches.
• The specific habitat of S. lugdunensis explains its low rate of occurrence as a blood culture contaminant.