Inducible, transferable resistance to vancomycin in Enterococcus faecium, D399

Area of Science:

• Microbiology
• Infectious Diseases
• Molecular Biology

Background:

• Enterococcus faecium is a significant cause of healthcare-associated infections.
• Vancomycin resistance in enterococci is a growing public health concern.
• Previous studies identified inducible glycopeptide resistance mechanisms in Enterococcus faecalis.

Purpose of the Study:

• To characterize the vancomycin resistance of Enterococcus faecium D399.
• To investigate the mechanism and transferability of this resistance.
• To compare the resistance phenotype with previously described enterococcal strains.

Main Methods:

• Isolation and identification of Enterococcus faecium D399 from clinical samples.
• Determination of vancomycin Minimum Inhibitory Concentration (MIC).
• Assessment of resistance inducibility and transferability via conjugation experiments.
• Analysis of protein synthesis induction associated with resistance.

Main Results:

• Enterococcus faecium D399 demonstrated high-level vancomycin resistance (MIC = 1000 mg/l).
• The resistance was inducible and transferable to a susceptible strain (JH2-2).
• Resistance correlated with the induction of a 39 kDa protein synthesis, similar to E. faecalis A256.
• The resistance phenotype of D399 showed some unique characteristics compared to other inducible resistance strains.

Conclusions:

• Enterococcus faecium D399 possesses an inducible and transferable vancomycin resistance mechanism.
• This finding suggests the dissemination of this glycopeptide resistance mechanism among enterococci.
• The unique resistance phenotype warrants further investigation into the molecular basis of resistance in D399.