Penicillin Resistance in Enterococcus faecalis: Molecular Determinants and Epidemiology

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Enterococcus faecalis is a major cause of hospital-acquired infections (HAIs).
• Combination therapy of penicillin and aminoglycoside is crucial for treating invasive HAIs.
• Penicillin resistance mechanisms in E. faecalis are critical to understand for effective treatment.

Purpose of the Study:

• To investigate the mechanisms of penicillin resistance in Enterococcus faecalis.
• To identify the association between penicillin resistance and specific high-risk enterococcal clonal complexes (HiRECCs).

Main Methods:

• Analysis of penicillin resistance mechanisms, including PBP5 modification, overproduction, and beta-lactamase expression.
• Identification and characterization of high-risk enterococcal clonal complexes (HiRECCs) associated with penicillin resistance.

Main Results:

• Penicillin resistance in E. faecalis is attributed to alterations in penicillin-binding protein (PBP5) and beta-lactamase activity.
• The penicillin-resistant phenotype is rarely observed but significantly linked to multi-resistant HiRECCs, specifically CC2 and CC9.

Conclusions:

• Understanding penicillin resistance mechanisms in E. faecalis is vital for managing HAIs.
• The association with HiRECCs like CC2 and CC9 suggests a potential for increased dissemination of multi-drug resistant strains.