Test Catalog

Test Id : OXVRP

Oxacillin-Hydrolyzing Beta-Lactamase (blaOXA-48-like) and Verona Integron-Encoded Metallo-Beta-Lactamase (blaVIM) in Gram-Negative Bacilli, Molecular Detection, PCR, Varies

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

Assessing pure isolates of gram-negative bacilli for mechanism of carbapenem resistance


This is a rapid molecular test that detects OXA-48-like beta-lactamase and VIM metallo-beta-lactamase DNA associated with antimicrobial resistance in isolates of gram-negative bacilli.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

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

Real-Time Polymerase Chain Reaction (PCR) using LightCycler and Fluorescent Resonance Energy Transfer (FRET)

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


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

OXA-48 and VIM PCR

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

Carbapenem resistant Enterobacteriaceae

Carbapenem resistant CRE

Carbapenemase producing, carbapenem resistant Enterobacteriaceae









Specimen Type
Describes the specimen type validated for testing


Ordering Guidance

This assay should be used for testing of isolates of gram-negative bacilli. If testing directly from rectal swabs, perirectal swabs, anal swabs, perianal swabs, or stool is desired, order OVSRP / Oxacillin-Hydrolyzing Beta-Lactamase (blaOXA-48-like) and Verona Integron-Encoded Metallo-Beta-Lactamase (blaVIM) DNA Surveillance, PCR, Varies


Other mechanisms of carbapenem resistance, including other carbapenemase-types, porin mutations, or hyperexpression of drug efflux pumps may result in carbapenem resistance. These are not detected by this assay. If testing for Klebsiella pneumoniae carbapenemase (KPC) or New Delhi metallo-beta-lactamase (NDM) is desired, order KPNRP / KPC (blaKPC) and NDM (blaNDM) in Gram-Negative Bacilli, Molecular Detection, PCR.

Additional Testing Requirements

1. Organism identification must be provided. If organism identification is unknown, concomitantly order IDENT / Organism Referred for Identification, Aerobic Bacteria.

2. If susceptibility testing is needed; also order ZMMLS / Antimicrobial Susceptibility, Aerobic Bacteria, Varies.

3. If testing for Klebsiella pneumoniae carbapenemase or New Delhi metallo-beta-lactamase is also needed; also order KPNRP / KPC (blaKPC) and NDM (blaNDM) in Gram-Negative Bacilli, Molecular Detection, PCR.

Shipping Instructions

1. For shipping information see Infectious Specimen Shipping Guidelines .

2. Place specimen in a large infectious container and label as an etiologic agent/infectious substance, if appropriate.

Necessary Information

Organism identification and specimen source are required.


Question ID Description Answers
OXORG Organism Identified by Client
OXSRC Specimen Source

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 oxacillin-hydrolyzing beta-lactamase (OXA-48-like) or Verona integron-encoded metallo-beta-lactamase (VIM) DNA is unlikely.


Supplies: Infectious Container, Large (T146)

Container/Tube: Slant

Specimen Volume: Isolate

Collection Instructions:

1. Perform isolation of infecting bacteria.

2. Bacterial organism must be submitted in pure culture, actively growing. Do not submit mixed cultures.

Special Instructions
Library of PDFs including pertinent information and forms related to the test


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

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

Agar plate
Mixed culture

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 Ambient (preferred)

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

Assessing pure isolates of gram-negative bacilli for mechanism of carbapenem resistance

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

In the United States, Klebsiella pneumoniae carbapenemase (KPC) is the most common carbapenemase, followed by New Delhi metallo-beta-lactamase (NDM). OXA-48-like (oxacillin-hydrolyzing beta-lactamase) and VIM (Verona integron-encoded metallo-beta-lactamase) carbapenemases predominate in other parts of the world but are also seen in the United States. The genes blaOXA-48-like and blaVIM encode OXA-48-like and VIM enzyme production, respectively. Polymerase chain reaction is a sensitive, specific, and rapid means of identifying these genes. This test detects the genes encoding OXA-48-like  and VIM types of beta-lactamases in bacterial isolates.

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.

Not applicable

Provides information to assist in interpretation of the test results

This polymerase chain reaction (PCR) detects and differentiates blaOXA-48-like and blaVIM. A positive blaOXA-48-like (oxacillin-hydrolyzing beta-lactamase) PCR result indicates that the isolate carries blaOXA-48-like. A positive VIM (Verona integron-encoded metallo-beta-lactamase) PCR result indicates the isolate carries blaVIM. A negative result indicates the absence of detectable DNA.

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

False-negative results may occur due to inhibition of polymerase chain reaction, sequence variability underlying primers and probes, or the presence of the blaOXA-48-like or blaVIM genes in quantities lower than the limit of detection of the assay.

Supportive Data

The assay was validated using 46 gram-negative bacilli, including 30 carbapenemase-producers (26 OXA/VIM-type, 1 NMC/IMI, 1 NDM-1, and 2 KPC) and 2 gram-positive organisms. The assay provided 100% sensitivity and specificity for both targets.

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

1. Bush K, Fisher JF: Epidemiological expansion, structural studies, and clinical challenges of new beta-lactamases from gram-negative bacteria. Annu Rev Microbiol. 2011;65:455-478

2. Poirel L, Potron A, Nordmann P: OXA-48-like carbapenemases: the phantom menace. J Antimicrob Chemother. 2012 Jul;67(7):1597-1606

3. Nordmann P, Naas T, Poirel L: Global spread of carbapenemase-producing Enterobacteriaceae. Emerg Infect Dis. 2011 Oct;17(10):1791-1798

Special Instructions
Library of PDFs including pertinent information and forms related to the test

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

Isolates are lysed in buffer to release their DNA. This assay amplifies and detects a specific portion of the genes encoding the OXA-48-like (oxacillin-hydrolyzing beta-lactamase) and VIM (Verona integron-encoded metallo- beta-lactamase) enzymes. The LightCycler instrument amplifies and monitors target nucleic acid sequences by fluorescence during PCR cycling. This is an automated PCR system that can rapidly detect amplified product development through stringent air-controlled temperature cycling and capillary cuvettes. The detection of amplified products is based on the fluorescent-resonance energy transfer (FRET) principle. For FRET product detection, hybridization probes with a donor fluorophore, fluorescein, on the 3' end are excited by an external light source, which emits light that is absorbed by secondary hybridization probes with acceptor fluorophores, LC-Red 610 (blaOXA-48-like) and LC-Red 670 (blaVIM) on the 5' end. The acceptor fluorophore then emits a light of a different wavelength that can be measured with a signal that is proportional to the amount of specific PCR product. The detection process is completed in less than 1 hour using a closed tube system.(Fernandez J, Cunningham SA, Fernandez-Verdugo A, et al: Evaluation of a real-time PCR assay for rectal screening of OXA-48-producing Enterobacteriaceae in a general intensive care unit of an endemic hospital. Diagn Microbiol Infect Dis. 2017 Jul;88(3):252-258. doi: 10.1016/j.diagmicrobio.2017.04.001)

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


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.

2 to 5 days

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

30 days

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


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 account representative. 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, and its performance characteristics 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.

87150 x 2

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
OXVRP OXA-48 and VIM PCR 85502-3
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
OXORG Organism Identified by Client 43409-2
OXSRC Specimen Source 31208-2
41743 OXA-48-like PCR 85503-1
41744 VIM PCR 85501-5

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 | PHP Pdf | CMS 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