Local genetic patterns within a vancomycin-resistant Enterococcus faecalis clone isolated in three hospitals in...

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Enterococcus faecalis is an opportunistic pathogen.
• The Tn1546 transposon is a key element in the dissemination of vancomycin resistance.
• Understanding clonal spread and genetic variation is crucial for infection control.

Purpose of the Study:

• To investigate the genetic diversity and geographical distribution of Enterococcus faecalis clones.
• To characterize Tn1546 variants within these clones.
• To identify novel genetic elements associated with Tn1546.

Main Methods:

• Pulsed-field gel electrophoresis (PFGE) for subtyping bacterial isolates.
• Analysis of Tn1546 transposon variants using molecular techniques.
• Identification of insertion sequences within transposons.

Main Results:

• Eight distinct PFGE subtypes and six Tn1546 variants were identified in Enterococcus faecalis isolates.
• Specific clonal subtypes were associated with individual hospitals.
• Tn1546 variants showed varied distribution patterns across the hospitals.
• The first instance of an ISEf1 insertion within the Tn1546 transposon was reported.

Conclusions:

• A single Enterococcus faecalis clone has disseminated across multiple Portuguese hospitals.
• Genetic diversity exists within this clone, particularly concerning Tn1546 variants.
• The discovery of ISEf1 within Tn1546 may have implications for vancomycin resistance gene transfer.