Comparison of epidemiologic markers for Staphylococcus epidermidis.

Area of Science:

• Microbiology
• Epidemiology
• Molecular Biology

Background:

• Staphylococcus epidermidis is a common bacterium found on human skin and mucous membranes.
• Accurate identification of bacterial strains is crucial for epidemiological studies and understanding infection transmission.

Purpose of the Study:

• To evaluate the effectiveness of different methods for identifying Staphylococcus epidermidis strains.
• To determine the most reliable parameters for establishing the identity of bacterial cultures from the same individual.

Main Methods:

• Comparison of antimicrobial phenotype, Staph-Ident profile number, phage typing, and plasmid profiling.
• Analysis of Staphylococcus epidermidis cultures isolated from the eyes and nose of the same individuals.

Main Results:

• No single method (antimicrobial phenotype, Staph-Ident, phage type, or plasmid profile) was sufficient for definitive strain identification.
• The most conclusive identification was achieved when cultures shared the same long phage type and had identical or similar plasmid profiles.
• Unusual plasmid profiles sometimes raised doubts about the reliability of plasmid profiling alone in epidemiological studies.

Conclusions:

• A combination of long phage type and similar plasmid profiles provides the most compelling data for identifying Staphylococcus epidermidis strains.
• Relying solely on plasmid profiles may not be sufficient for accurate strain identification in epidemiological investigations.
• Multiple discriminatory techniques are essential for robust bacterial strain typing.