Surveillance for antimicrobial resistance in enterococci

Area of Science:

• Clinical microbiology
• Infectious diseases
• Antimicrobial resistance

Background:

• Antimicrobial-resistant enterococci are significant nosocomial pathogens.
• Periodic local resistance pattern surveys are recommended for hospitals.

Purpose of the Study:

• To characterize antimicrobial resistance profiles of Enterococcus species in Auckland.
• To establish a local susceptibility baseline for enterococcal isolates.

Main Methods:

• Enterococcal isolates from four distinct patient groups were analyzed.
• Testing included beta-lactamase production, susceptibility to amoxycillin, teicoplanin, vancomycin, and high-level gentamicin/streptomycin resistance.

Main Results:

• Of 433 isolates, 74% were E. faecalis, 12% E. faecium. No beta-lactamase production was detected.
• All E. faecalis were amoxycillin-susceptible; two E. faecium and one other species showed resistance.
• Teicoplanin susceptibility was universal. Vancomycin resistance was rare, primarily intermediate in E. gallinarum/casseliflavus. High-level gentamicin and streptomycin resistance occurred in 15% and 12% of isolates, respectively.

Conclusions:

• Vancomycin resistance is uncommon and mainly associated with E. gallinarum/casseliflavus.
• The study established local enterococcal susceptibility patterns.
• This data facilitates comparison with other regions and monitors emerging resistance trends.