[Relationship between an offensive smell given off from human foot and Staphylococcus epidermidis]

Area of Science:

• Microbiology
• Dermatology
• Biochemistry

Background:

• Foot odor is a common concern, often linked to microbial activity on the skin.
• Gram-positive bacteria, particularly Staphylococcus species, are frequently found on human skin.
• Identifying the specific microorganisms responsible for foot odor is crucial for developing effective treatments.

Purpose of the Study:

• To identify the bacteria responsible for the offensive smell of human feet.
• To investigate the potential role of Staphylococcus epidermidis in producing foot odor.
• To evaluate the efficacy of a deoxycholic acid lotion in reducing S. epidermidis and foot odor.

Main Methods:

• Swab samples were collected from the foot skins of 17 volunteers.
• Bacteria were isolated and identified using an ID-kit SP-18.
• S. epidermidis was incubated on agar plates with oleic acid and Tween 80 to assess odor production.
• A lotion containing deoxycholic acid was applied to volunteers' feet, and bacterial counts and odor were compared to controls.

Main Results:

• The predominant bacteria isolated were gram-positive cocci, identified as Staphylococcus epidermidis.
• S. epidermidis produced an offensive smell similar to human foot odor when incubated under specific conditions.
• Other staphylococcal species and yeasts isolated did not produce a similar offensive smell.
• Application of the deoxycholic acid lotion significantly decreased S. epidermidis counts and inhibited foot odor.

Conclusions:

• Staphylococcus epidermidis is likely the primary source of the offensive smell associated with human feet.
• Inhibiting the growth of S. epidermidis can effectively reduce foot odor.
• Deoxycholic acid demonstrates potential as a targeted treatment for foot odor by reducing S. epidermidis populations.