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Slime layer formation and the prevalence of mecA and aap genes in Staphylococcus epidermidis isolates

Mohammad Reza Pourmand1, Zahra Abdossamadi, Mohammad Hossein Salari

  • 1Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Iran. mpourmand@tums.ac.ir

Journal of Infection in Developing Countries
|February 19, 2011
PubMed
Abstract

Insights

Slime-producing Staphylococcus epidermidis strains, common in healthcare workers, show significant antibiotic resistance. Surveillance of these nasal carriers could help prevent hospital-acquired infections.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Antimicrobial Resistance

Background:

  • Staphylococcus epidermidis is a common cause of healthcare-associated infections.
  • Slime production by S. epidermidis can confer antibiotic resistance.
  • Understanding resistance patterns and virulence factors in healthcare personnel is crucial for infection control.

Purpose of the Study:

  • To determine antimicrobial resistance patterns in S. epidermidis nasal isolates from healthcare workers.
  • To assess the prevalence of slime production and associated genes (mecA, aap).
  • To investigate the relationship between slime production, antibiotic resistance, and specific gene markers.

Main Methods:

  • A cross-sectional study involving 163 nasal swabs from healthcare staff.
  • S. epidermidis isolates were tested for slime production using congo red agar.
  • Antibiotic resistance profiling and PCR for mecA and aap genes were conducted.

Main Results:

  • 99 S. epidermidis strains were isolated from 58.9% of participants.
  • 34.3% of isolates produced slime, with a significant association with resistance to penicillin, oxacillin, tetracycline, erythromycin, and clindamycin.
  • High prevalence of mecA (95.8%) and aap (94.8%) genes was observed, but not all gene-positive strains exhibited corresponding phenotypes (e.g., oxacillin resistance, slime production).

Conclusions:

  • Slime-producing, oxacillin-resistant S. epidermidis nasal colonization in healthcare workers is prevalent.
  • Monitoring healthcare personnel for these S. epidermidis strains may aid in interrupting the transmission of hospital-acquired infections.
  • Further research is needed to fully elucidate the correlation between genotype and phenotype in S. epidermidis virulence.

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