Related Experiment Videos
Survey for virulence determinants among Enterococcus faecalis isolated from different sources.
Roberta Creti1, Monica Imperi1, Lucia Bertuccini1
1Laboratorio di Batteriologia1 and Laboratorio di Ultrastrutture2, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy 3Dipartimento di Medicina Clinica, Università 'La Sapienza', P. le Aldo Moro, 5-00185 Rome, Italy.
Journal of Medical Microbiology
|December 10, 2003
Summary
Enterococcus faecalis virulence factors vary by source. Urinary tract infection strains had the most factors, while endocarditis and environmental strains had fewer. Gene presence didn't always mean expression.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Enterococcus faecalis is a significant opportunistic pathogen.
- Virulence factors play a crucial role in E. faecalis pathogenesis.
- Understanding the distribution of virulence factors is key to predicting clinical outcomes.
Purpose of the Study:
- To screen clinical, commensal, and environmental E. faecalis isolates for key virulence factor genes.
- To investigate the correlation between the presence of specific genes and their phenotypic expression.
- To determine the association of virulence factors with different infection sources.
Main Methods:
- Multiplex PCR was used to detect virulence factor genes (ace, efaA, cylA, gelE, asa1, asa373, esp, EF0591, EF3314).
- Phenotypic expression of gelatinase, CylA, and aggregation substances was assessed.
- Isolates were categorized by source: clinical (endocarditis, UTI, bacteraemia, biliary stents), healthy individuals, and environment.
Main Results:
- The ace, efaA, and EF3314 genes were universally present. Gelatinase (gelE) was the most common gene but expression varied.
- Esp and CylA genes were absent in endocarditis isolates; esp was associated with UTI and bacteraemia.
- Commensal strains consistently harbored aggregation substance genes. UTI isolates exhibited the highest number of virulence factors.
Conclusions:
- Virulence factor gene profiles differ significantly based on the source of E. faecalis isolates.
- The presence of virulence factor genes does not always correlate with their functional expression.
- Urinary tract infection isolates are particularly enriched with virulence factors, suggesting a higher pathogenic potential.