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Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
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Bacterial insertion sequence IS256 as a potential molecular marker to discriminate invasive strains from commensal

J Gu1, H Li, M Li

  • 1Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, People's Republic of China.

The Journal of Hospital Infection
|October 26, 2005
PubMed

Insights

Distinguishing invasive Staphylococcus epidermidis from commensal strains is vital. The study found polysaccharide intercellular adhesion (PIA) production was not a reliable marker, but the insertion sequence element IS256 was more frequent in invasive strains, suggesting it as a novel diagnostic marker.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genomics

Background:

  • Staphylococcus epidermidis is a common cause of hospital-acquired infections, often linked to medical devices.
  • Differentiating between invasive and commensal S. epidermidis is critical for effective clinical management.
  • The ica gene locus, encoding polysaccharide intercellular adhesion (PIA), has been proposed as a marker for infectivity, but results are controversial.

Purpose of the Study:

  • To identify novel genetic markers that can reliably distinguish invasive S. epidermidis strains from commensal strains.
  • To investigate the utility of the ica gene locus and polysaccharide intercellular adhesion (PIA) production as discriminators.

Main Methods:

  • Comparative analysis of genome sequences from clinical and commensal Staphylococcus epidermidis strains.
  • Evaluation of polysaccharide intercellular adhesion (PIA) production in clinical isolates.
  • Assessment of the frequency of the insertion sequence element IS256 in different strain types.

Main Results:

  • Polysaccharide intercellular adhesion (PIA) production was not significantly elevated in clinical S. epidermidis strains.
  • The insertion sequence element IS256 was found significantly more frequently in strains of clinical origin.
  • The presence of IS256 correlates with invasive S. epidermidis, unlike the ica gene locus.

Conclusions:

  • The ica gene locus and PIA production are not reliable markers for differentiating invasive from commensal S. epidermidis.
  • The bacterial insertion sequence element IS256 is a promising novel molecular marker for identifying invasive S. epidermidis strains.
  • IS256 may aid in clinical decision-making for managing S. epidermidis infections.

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