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Virulence of Enterococcus isolates collected in Lower Silesia (Poland)

Ewa Dworniczek1, Łukasz Wojciech, Beata Sobieszczańska

  • 1Department of Microbiology, Medical University of Wrocław, Poland. ekoks@mbio.am.wroc.pl

Scandinavian Journal of Infectious Diseases
|August 30, 2005
PubMed

Insights

This study investigated enterococcal strains from clinical samples, finding that while many strains could adhere to cells and possessed virulence factors like the esp gene and biofilm formation, adherence was not significantly linked to these factors.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Bacterial Pathogenesis

Background:

  • Enterococci are opportunistic pathogens causing significant nosocomial infections.
  • Understanding enterococcal virulence factors and adherence mechanisms is crucial for infection control.

Purpose of the Study:

  • To investigate the adherence capabilities of various enterococcal species to Caco-2 and HEp-2 cell lines.
  • To determine the prevalence of specific virulence factors, including the esp gene, biofilm formation, haemolysins, DNAse, and lipase, in these clinical isolates.
  • To assess the correlation between enterococcal adherence and the presence of these virulence factors.

Main Methods:

  • Phenotypic characterization of 148 enterococcal strains (E. faecalis, E. faecium, E. gallinarum, E. casseliflavus, E. durans) from clinical specimens.
  • In vitro assessment of bacterial adherence to Caco-2 and HEp-2 cell lines, noting different adherence patterns.
  • Molecular detection of the esp gene and assays for biofilm formation, haemolysin, DNAse, and lipase production.

Main Results:

  • Enterococcal strains exhibited diverse adherence patterns to both cell lines, with aggregative adherence being most common in E. faecalis and E. faecium.
  • The prevalence of virulence factors was: esp gene (53.4%), biofilm formation (45.3%), lipase (33.1%), haemolysins (15.5%), and DNAse (12.2%).
  • No significant association was found between the adherence of enterococcal strains and the presence of the investigated virulence factors.

Conclusions:

  • Enterococcal adherence to intestinal and respiratory cell lines is a common trait, irrespective of species.
  • The tested virulence factors (esp gene, biofilm, haemolysins, DNAse, lipase) are prevalent in clinical enterococcal isolates but do not appear to be the primary drivers of cell adherence in this cohort.
  • Further research is needed to elucidate the specific mechanisms governing enterococcal adherence and their role in pathogenesis.

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