Carbapenemase Detection, Modified Hodge Test
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Determining carbapenem resistance
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Modified Hodge Test
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Carbapenamase-Modified Hodge Test
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Specimen Volume: Isolate
1. Submit Enterobacteriaceae species in pure culture, actively growing.
2. Place specimen in a large infectious container (Supply T146) and label as an etiologic agent.
1. Specimen source and organism identification are required.
2. See Infectious Specimen Shipping Guidelines in Special Instructions for shipping information.
Forms: If not ordering electronically, submit a Microbiology Request Form (Supply T244) with the specimen.
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Resistance to antibiotic therapy via production of the enzyme carbapenemase by Klebsiella pneumoniae and other members of Enterobacteriaceae is becoming more common. This resistance is not always detected by conventional antimicrobial susceptibility testing, which may result in inappropriate antimicrobial therapy for the patient.
In Enterobacteriaceae, the gene blaKPC, which encodes KPC (Klebsiella pneumoniae carbapenemase) production, can be detected by real-time PCR. However, molecular methods have not been established for other carbapenemases.
The modified Hodge test, a phenotypic method, is recommended by the Clinical and Laboratory Standards Institute (CLSI) as the method to detect carbapenemases.
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.
A positive result indicates the production of carbapenemase.
A negative result indicates the lack of production of carbapenemase.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not routinely performed on Enterobacteriaceae determined to be fully resistant to carbapenems in the Mayo Microbiology Laboratory.
A collection of 14 isolates (11 Klebsiella pneumoniae and 1 each Enterobacter cloacae, Citrobacter freundii, and Escherichia coli) obtained from the CDC were studied for the detection of carbapenemase production. Eleven (including the Enterobacter cloacae, Citrobacter freundii, and Escherichia coli isolates) were positive and 3 were negative with Mayo's modified Hodge test and with the Mayo-developed KPC real-time PCR assay, as well as with modified Hodge testing and the KPC real-time PCR assay performed at CDC.
To further support this data, an additional 62 specimens were tested comparing Mayo's modified Hodge test to the Mayo-developed KPC real-time PCR assay. The modified Hodge test and the real-time PCR assay showed 100% concordance for both positive (n=10) and negative (n=52) paired results.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
The 2009 CLSI Standards for Antimicrobial Susceptibility Testing. CLSI Audioconference. Janet Hindler. Original air date: January 21, 2009
Method Description Describes how the test is performed and provides a method-specific reference
A standardized suspension of Escherichia coli ATCC 25922 is streaked across the surface of Mueller-Hinton agar plates. A single antibiotic disk is dropped onto the center of the plate. The carbapenems ertapenem and meropenem are tested. The patient strain is streaked in a thin straight line from the edge of the plate to the disk. Enhanced growth at the intersection of the streak with the zone of inhibition indicates carbapenemase production.(Clinical and Laboratory Standards Institute/NCCLS. 2009. Performance Standards for Antimicrobial Susceptibility Testing. 19th informational supplement. M100-S19. CLSI, Wayne, PA)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Sunday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Performing Laboratory Location The location of the laboratory that performs the test
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's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test uses a standard method. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.
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 Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|HODGE||Carbapenamase-Modified Hodge Test||In Process|