Characteristics of clinical and environmental vanM-carrying vancomycin-resistant enterococci isolates from an...

Area of Science:

• Microbiology
• Infectious Diseases
• Molecular Epidemiology

Background:

• The vanM gene confers glycopeptide resistance in Enterococcus faecium.
• vanM-carrying Enterococcus faecium was first identified in Shanghai, China, in 2006 and became predominant by 2011.
• Glycopeptide resistance is a significant concern in healthcare settings.

Observation:

• A vanM-positive Enterococcus faecium isolate was detected in a patient's bloodstream in an intensive care unit (ICU) in Hangzhou, China, in 2014.
• Subsequent screening revealed vanM-positive Enterococcus faecium in the patient's rectal swab and on environmental surfaces within the ICU.
• A total of 45 vanM-positive isolates were recovered, including bloodstream, rectal, and environmental samples.

Findings:

• The recovered isolates exhibited four distinct pulsed-field gel electrophoresis (PFGE) patterns and belonged to two sequence types (ST78 and ST564).
• Genetic analysis confirmed that the vanM gene structure in these Hangzhou isolates was similar to the original isolate from Shanghai.
• This indicates a potential clonal spread or conserved genetic environment of the vanM gene.

Implications:

• The study demonstrates the emergence of vanM-carrying Enterococcus faecium infections and environmental contamination in an ICU outside of Shanghai.
• This finding underscores the expanding geographical distribution and clinical relevance of vanM resistance in China.
• Effective infection control strategies are crucial to prevent the further spread of these resistant bacteria in healthcare environments.