Effect of growth medium on hydrophobicity of Staphylococcus epidermidis.

This research investigates how different growth mediums affect the hydrophobicity of the bacteria Staphylococcus epidermidis, finding that the horse blood agar growth medium produced the most hydrophobic bacteria.

Research Background

• The objective of this study was to determine how the growth medium—the substance in which bacteria are cultivated in the lab—impacts the hydrophobicity, or water-repelling properties, of Staphylococcus epidermidis.
• Staphylococcus epidermidis is a type of bacteria usually found on the skin. It is mostly harmless but can cause infection in immunocompromised individuals or when it enters the body through medical devices. Hydrophobicity plays a significant role in the bacteria’s ability to adhere to surfaces and form biofilms, which are protective colonies that contribute to infection.

Research Methodology

• The researchers used 24 different strains of Staphylococcus epidermidis, which had previously been identified as hydrophobic through an n-hexadecane adherence assay (HAA).
• Five different growth mediums were tested, namely horse blood agar (HBA), brain heart infusion agar (BHIA), brain heart infusion broth (BHIB), tryptic soy broth (TSB), and proteose peptone broth (PPB).

Findings

• All the bacterial strains exhibited hydrophobicity when grown on the horse blood agar medium.
• However, when the bacteria were grown in the other mediums, fewer strains displayed hydrophobic traits: 20 out of 24 in BHIA, 19 in BHIB, 15 in TSB, and 13 in PPB.

Conclusion

• The study concluded that horse blood agar was the most suitable medium for promoting hydrophobicity in Staphylococcus epidermidis. The brain heart infusion agar and brain heart infusion broth mediums were the next best options.
• This work provides important insights for research into Staphylococcus epidermidis. It highlights the need to consider the growth medium when studying hydrophobicity and other properties of bacteria, as the medium can significantly affect the results.