Related Experiment Videos
Outbreak of multidrug-resistant Enterococcus faecium with transferable vanB class vancomycin resistance
Abstract:
Enterococcus faecium strains resistant to ampicillin, high levels of gentamicin, and vancomycin but susceptible to teicoplanin (vanB class vancomycin resistance) were recovered from 37 patients during an outbreak involving a 250-bed university-affiliated hospital. Three isolates with vancomycin MICs ranging from 8 to 256 micrograms/ml all hybridized with a vanB probe. Restriction endonuclease analysis of chromosomal and plasmid DNA suggested that all isolates tested were derived from a single clone. Vancomycin resistance was shown to be transferable. Risk factors for acquiring the epidemic strain included proximity to another case patient (P, 0.0005) and exposure to a nurse who cared for another case patient (P, 0.007). Contamination of the environment by the epidemic strain occurred significantly more often when case patients had diarrhea (P, 0.001). Placing patients in private rooms and requiring the use of gowns as well as gloves by personnel controlled the outbreak. These findings suggest that multidrug-resistant E. faecium strains with transferable vanB class vancomycin resistance will emerge as important nosocomial pathogens. Because extensive environmental contamination may occur when affected patients develop diarrhea, barrier precautions, including the use of both gowns and gloves, should be implemented as soon as these pathogens are encountered.
Insights
A hospital outbreak of multidrug-resistant Enterococcus faecium with transferable vanB class vancomycin resistance was controlled by isolation and barrier precautions. Environmental contamination increased with patient diarrhea, necessitating strict gown and glove use.
Area of Science:
- Microbiology
- Infectious Diseases
- Hospital Epidemiology
Background:
- Nosocomial infections caused by multidrug-resistant Enterococcus faecium are a growing concern.
- The emergence of vancomycin resistance, particularly vanB class, poses significant treatment challenges.
Purpose of the Study:
- To investigate an outbreak of vancomycin-resistant Enterococcus faecium (VRE) at a university-affiliated hospital.
- To identify risk factors for acquisition and effective control measures for the epidemic strain.
Main Methods:
- Molecular typing (restriction endonuclease analysis) to assess clonality of isolates.
- Antimicrobial susceptibility testing, including vancomycin Minimum Inhibitory Concentrations (MICs).
- Plasmid and chromosomal DNA analysis to evaluate vancomycin resistance transferability.
Main Results:
- Thirty-seven patients were infected with a single clone of ampicillin-, gentamicin-, and vancomycin-resistant Enterococcus faecium (vanB type).
- Vancomycin resistance was transferable, with MICs ranging from 8 to 256 µg/ml.
- Proximity to other patients and exposure to healthcare workers caring for cases were significant risk factors.
- Environmental contamination was higher when patients had diarrhea.
- Isolation in private rooms and use of gowns and gloves controlled the outbreak.
Conclusions:
- Multidrug-resistant Enterococcus faecium with transferable vanB resistance is an emerging nosocomial pathogen.
- Diarrhea in infected patients significantly increases environmental contamination risk.
- Strict barrier precautions, including gowns and gloves, are crucial for controlling outbreaks of this VRE strain.