This test is usually ordered to detect VRE carriage in asymptomatic patients for infection control purposes. It is indicated to screen patients at risk for self-infection or for transmitting VRE to close contacts. The test may also be requested to document clearance of VRE carriage. A patient specimen is plated onto selective agar, typically containing 6 Ž ¼g/mL vancomycin. Any growth of Enterococcus likely represents VRE, but vancomycin resistance and identification should be confirmed by subsequent testing of the isolate. Swab specimens of the rectum or perianal skin are recommended for VRE screening cultures.
Turnaround time: 48 hours.
Interpretation
Expected results: Negative.
Limitations
Detection of VRE carriage may require submission of several samples, and collection from several potentially colonized sites.
Common pitfall: The VRE screening culture is usually not indicated for evaluation of potentially infected material. Because only selective media is used for screening, other potential pathogens would be missed if VRE screening culture only is requested. VRE grow well in wound and other cultures submitted for evaluation of infected specimens.