Molecular characterization of vancomycin-resistant Enterococcus faecium isolates from Bermuda.

Area of Science:

• Microbiology
• Infectious Diseases
• Molecular Epidemiology

Background:

• Vancomycin-resistant enterococci (VRE) pose a significant threat to public health globally.
• The molecular epidemiology of VRE on Bermuda Island was previously uncharacterized.
• Understanding VRE characteristics is crucial for effective infection control.

Purpose of the Study:

• To investigate the phenotypic and genotypic features of VRE isolates from Bermuda Island.
• To determine the genetic relatedness and antimicrobial resistance profiles of VRE.
• To identify potential sources and transmission patterns of VRE in the local healthcare setting.

Main Methods:

• Phenotypic analysis using chromogenic agar and E-tests for antimicrobial susceptibility.
• Genotypic characterization including polymerase chain reaction (PCR) for specific genes (vanA, esp).
• Molecular typing techniques such as pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were employed.

Main Results:

• Eighteen *Enterococcus faecium* isolates were analyzed, all exhibiting vancomycin resistance.
• All isolates were susceptible to linezolid and quinupristin/dalfopristin.
• The *vanA* and *esp* genes were detected in all isolates.
• MLST analysis identified sequence types predominantly linked to clonal complex 17 (CC17).

Conclusions:

• Bermuda Island VRE isolates are primarily *E. faecium* harboring the *vanA* gene.
• The prevalence of CC17 suggests a potential for hospital-acquired VRE outbreaks.
• Continued infection control, antibiotic stewardship, and surveillance are essential for managing VRE on the island.