Infections due to beta-lactamase-producing, high-level gentamicin-resistant Enterococcus faecalis

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Epidemiology

Background:

• Beta-lactamase-producing, high-level gentamicin-resistant Enterococcus faecalis (E. faecalis) poses a significant threat in healthcare settings.
• Understanding the risk factors and outcomes associated with this multidrug-resistant pathogen is crucial for effective infection control.

Purpose of the Study:

• To investigate risk factors, clinical features, molecular epidemiology, and treatment outcomes of an outbreak caused by beta-lactamase-producing, high-level gentamicin-resistant E. faecalis.
• To identify predictors for acquisition and mortality in patients infected or colonized with this resistant strain.

Main Methods:

• A case-control study was conducted comparing patients with E. faecalis infections/colonization (case patients) to those with susceptible strains (control patients).
• Molecular genetics techniques were used to analyze the epidemiology of the outbreak.
• Multivariate logistic regression identified independent risk factors for acquisition.

Main Results:

• Beta-lactamase production was identified in 8.2% of E. faecalis isolates.
• Significant risk factors for acquiring the resistant strain included a high APACHE II score (greater than 6) and prior antibiotic treatment.
• Mortality was higher in case patients (7.7%) compared to controls (0%).
• Treatment with beta-lactamase-stable antibiotics did not prevent fatal outcomes in all cases.

Conclusions:

• Severe underlying disease and previous antibiotic exposure are strong predictors for infection with beta-lactamase-producing, high-level gentamicin-resistant E. faecalis.
• Fatal outcomes can occur despite appropriate antibiotic therapy, emphasizing the need for enhanced infection control measures.
• These findings can guide the targeting of high-risk patients for preventive interventions.