Test Catalog

Test Id : VRERP

Vancomycin-Resistant Enterococcus, Molecular Detection, PCR, Varies

Useful For
Suggests clinical disorders or settings where the test may be helpful

Identifying carriers of vancomycin-resistant enterococci

Highlights

This test detects the presence of either vanA or vanB, which confer vancomycin resistance in Enterococcus faecalis and Enterococcus faecium (and occasionally other organisms).

Method Name
A short description of the method used to perform the test

Real-Time Polymerase Chain Reaction (PCR)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

VRE PCR

Aliases
Lists additional common names for a test, as an aid in searching

VRE (Vancomycin-Resistant Enterococcus)

Specimen Type
Describes the specimen type validated for testing

Varies

Necessary Information

Specimen source is required.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

The high sensitivity of amplification by polymerase chain reaction requires the specimen to be processed in an environment in which contamination of the specimen by vancomycin-resistant Enterococcus DNA is unlikely.

 

Submit only 1 of the following specimens:

 

Preferred:

Specimen Type: Perianal, perirectal, rectal, anal

Supplies: Culturette (BBL Culture Swab) (T092)

Container/Tube: Culture transport swab (Dacron or rayon swab with aluminum or plastic shaft with either Stuart or Amies liquid medium)

Specimen Volume: Swab

Specimen Stability Information: Refrigerated (preferred)/Frozen 

 

Acceptable:

Specimen Type: Preserved Feces

Supplies: C and S Vial (T058)

Container/Tube: Commercially available transport system specific for recovery of enteric pathogens from fecal specimens (15 mL of non-nutritive transport medium containing phenol red as a pH indicator, either Cary-Blair, Para-Pak C and S vial)

Specimen Volume: Representative portion of feces

Collection Instructions:

1. Collect fresh feces and submit 1 gram or 5 mL in container with transport medium.

2. Place feces in preservative within 2 hours of collection.

Specimen Stability Information: Ambient (preferred)/ Refrigerated

 

Specimen Type: Unpreserved feces

Supplies:

-Stool Container, Small (Random), 4 oz Random (T288)

-Stool Collection Kit, Random (T635)

Container/Tube: Fecal container

Specimen Volume: Representative portion of feces

Collection Instructions: Collect fresh fecal specimen and submit representative sample in fecal container.

Specimen Stability Information: Refrigerated (preferred)/Frozen

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

See Specimen Required

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

E-swab, calcium alginate or, cotton-tipped swab
Swab sent in gel transport medium, viral or universal transport medium
Dry swab
Formalin or PVA fixative
Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Varies Varies (preferred)

Useful For
Suggests clinical disorders or settings where the test may be helpful

Identifying carriers of vancomycin-resistant enterococci

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Vancomycin-resistant enterococci (VRE) are major nosocomial pathogens. Patients who are particularly vulnerable to fatal disease from VRE include those with hematologic malignancies and liver transplants. Nosocomial spread of VRE occurs as the result of fecal carriage. Risks for both colonization and infection include prolonged hospitalization, intensive care unit stay, transplantation, hematologic malignancies, and prolonged exposure to antibiotics.

 

The Centers for Disease Control and Prevention provides recommendations to prevent the spread of VRE in institutional settings. These recommendations include isolation of patients experiencing active VRE infection, screening of patients by perianal swab or fecal testing to identify carriers of VRE, and subsequent isolation or cohorting of VRE carriers. Identification and isolation of VRE carriers has been shown to be cost-effective.

 

In Enterococcus faecalis or E faecium, vancomycin resistance is usually associated with the presence of vanA or vanB. The presence of these genes is detected by a molecular method in this assay.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

Interpretation
Provides information to assist in interpretation of the test results

Positive test results indicate the presence of either vanA or vanB, which confer vancomycin resistance in Enterococcus faecalis and Enterococcus faecium (and occasionally other organisms). Patients with a positive test result should be placed in isolation or cohorted with other vancomycin-resistant enterococci (VRE) carriers according to the institution's infection control practices.

 

A negative result indicates the absence of detectable vanA or vanB DNA, but does not rule-out carrier status and may occur due to inhibition of polymerase chain reaction (PCR), sequence variability underlying primers or probes, or the presence of VRE DNA in quantities less than the limit of detection of the assay. In the rare event that PCR testing appears to be negative but there is evidence of PCR inhibition, the result will read "PCR inhibition present." In such cases, a new specimen should be submitted for repeat testing.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

A positive result does not imply the presence of vancomycin-resistant enterococci (VRE) disease; the presence of vanA or vanB correlates with colonization by VRE. Colonization with VRE is not associated with any signs or symptoms.

 

vanA or vanB may occasionally be found in organisms other than enterococci.

Supportive Data

Perianal swabs (894) were evaluated for the presence of vanA or vanB DNA by the vancomycin-resistant enterococci (VRE) polymerase chain reaction (PCR) assay and compared to culture using selective and differential media. Compared to culture the VRE PCR assay was 98% sensitive and 98% specific. The VRE PCR assay detected 35 more positive specimens than the culture method. No cross-reactivity was seen when tested on a panel of pathogenic and normal flora bacteria of the gastrointestinal tract. Enterococcus species containing the vanC gene were not detected with the VRE PCR assay.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Procop GW, Church DL, Hall GS, et al. Gram-positive cocci, Part II: Streptococci, Enterococci, and the “Streptococcus-like” bacteria. In: Koneman’s Color Atlas and Textbook of Diagnostic Microbiology. 7th ed. Wolters Kluwer Lippincott Williams and Wilkins; 2017:801-804

2. Mayo Medical Laboratories Communique: Vancomycin-resistant enterococci: Colonization, infection, detection, and treatment. Vol 32, No. 11, November 2007

3. Zirakzadeh A, Patel R: Epidemiology and mechanisms of glycopeptide resistance in enterococci. Curr Opin Infect Dis. 2005;18:507-512. doi: 10.1097/01.qco.0000186849.54040.2a

4. Zirakzadeh A, Patel R: Vancomycin-resistant enterococci colonization, infection detection and treatment. Mayo Clinic Proc. 2006;81:529-536. doi: 10.4065/81.4.529

5. Patel R: Enterococcal-type glycopeptide resistance genes in non-enterococcal organisms. FEMS Microbiol Lett. 2000 Apr 1;185(1):1-7. doi: 10.1111/j.1574-6968.2000.tb09032.x

Method Description
Describes how the test is performed and provides a method-specific reference

Bacterial DNA is extracted from the specimen. Using the LightCycler instrument and fluorescent energy transfer probes, vanA and vanB genes responsible for vancomycin resistance in enterococci are detected directly from perianal swabs or fecal specimens.(Sloan LM, Uhl JR, Vetter EA, et al: Comparison of the Roche LightCycler vanA/vanB detection assay and culture for detection of vancomycin-resistant enterococci from perianal swabs. J Clin Microbiol 2004;42:2636-2643. doi: 10.1128/JCM.42.6.2636-2643.2004; Hefazi M, Damlaj M, Alkhateeb HB, et al: Vancomycin-resistant Enterococcus colonization and bloodstream infection: prevalence, risk factors, and the impact on early outcomes after allogeneic hematopoietic cell transplantation in patients with acute myeloid leukemia. Transplant Infect Dis 2016 Sept 19;18(6):913-920. doi: 10.1111/tid.12612)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 4 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

3 days if received in swab transport media; 7 days if received in C and S Vial

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

87500

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports