Test Catalog

Test Id : ECOLI

Shiga Toxin Escherichia coli Antigen, Feces

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

Rapid screening for EHEC serotypes including Escherichia coli O157:H7.

 

This test should serve as an adjunct to culture. However, in some situations when recovery of the organism by culture is not optimal (e.g. delayed transport of the specimen or transport of the specimen in preservative), or when isolation of the organism is not required for epidemiologic studies, this test may be considered as the preferred diagnostic method.

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

Enzyme-Linked Immunosorbent Assay (ELISA)

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

No

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

Shiga Toxin E. coli Ag, F

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

E. coli 0157

Enteropathogenic E. coli

Escherichia Coli 0157 Stool Antigen Detection

Verotoxin Assay

Specimen Type
Describes the specimen type validated for testing

Fecal

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

Submit only 1 of the following specimens:

 

Preserved Stool

Container/Tube: Culture and sensitivity media

Specimen Volume: 10 g of diarrheal (liquid or loose gives optimal results) stool

Specimen Stability Information: Refrigerated

 

Unpreserved Stool

Collection Container/Tube: Stool container

Submission Container/Tube: Plastic container

Specimen Volume: 10 g of unpreserved diarrheal (liquid or loose gives optimal results) stool

Specimen Stability Information: Frozen/Refrigerated <48 hours

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

2 g

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

All specimen will be evaluated at Mayo Clinic Laboratories for test suitability.

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
Fecal Refrigerated (preferred) 48 hours
Frozen 48 hours

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

Rapid screening for EHEC serotypes including Escherichia coli O157:H7.

 

This test should serve as an adjunct to culture. However, in some situations when recovery of the organism by culture is not optimal (e.g. delayed transport of the specimen or transport of the specimen in preservative), or when isolation of the organism is not required for epidemiologic studies, this test may be considered as the preferred diagnostic method.

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

Shiga toxin-producing Escherichia coli (STEC) have been recognized as agents of diarrhea and of sporadic cases and serious outbreaks of life-threatening hemorrhagic colitis and hemolytic uremic syndrome (HUS). Escherichia coli O157:H7 is the most frequently isolated enterohemorrhagic Escherichia coli (EHEC) serotype, but at least 50 serotypes have been implicated in the production of cytotoxins and development of complications.  

 

Conventional testing methods for Escherichia coli O157: H7 involve isolation of the organism from fecal cultures followed by biochemical and immunologic confirmation. This method usually requires 72 hours for complete identification.  

 

At this time, because antimicrobial therapy does not appear to be useful for treating the disease and may even increase the risk of HUS, recovery of Escherichia coli O157: H7 by culture for antimicrobial susceptibility testing is not necessary. The rapid diagnosis of Escherichia coli O157:H7 directly from fecal specimens is preferred to avoid unnecessary diagnostic procedures and inappropriate antimicrobial therapy and to identify common sources linked to transmission.

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

A positive result suggests the presence of Shiga-like toxin 1 or 2. It is recommended that all positive specimens be cultured to confirm the presence of enteropathogenic coli.

 

A negative result does not rule out the presence of enteropathogenic Escherichia coli; detectable antigen levels may not be produced until 3-6 days after the development of symptoms.

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

Antibiotic treatment prior to specimen collection may affect this assay; some antibiotics have the potential to destroy the cell wall component detected in this enzyme-linked immunosorbent assay (ELISA).

Supportive Data

This FDA-approved test was compared with Mayo's standard culture method for detecting Escherichia coli O157 using 46 reference specimens and 38 in-house specimens. The sensitivity (92%) and specificity (97%) of the assay was to equal culture. The assay had no cross reaction with stools containing other fecal pathogens including Aeromonas, Shigella sonnei, Beta strep (not Group A), Salmonella species (not typhi),Campylobacter jejuni , and yeast.

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

1. Karmali MA: Infection by verocytotoxin-producing Escherichia coli. Clin Microbiol Rev 1989;2:15-38

2. Karmali MA, Petric M, Lim C, et al: The association between idiopathic hemolytic uremic syndrome and infection by verotoxin-producing Escherichia coli. J Infect Dis 1985;151:775-782

3. Griffin PM, Ostroff SM, Tauxe RV, et al: Illnesses associated with Escherichia coli O157:H7 infections. A broad clinical spectrum. Ann Intern Med 1988;109:705-712

4. Wong CS, Jelacic S, Habeeb RL, et al: The risk of the hemolytic-uremic syndrome after antibiotic treatment of Escherichia coli O157:H7 infections. N Engl J Med 2000;342:1930-1936

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

An enzyme-linked immunosorbent assay microplate assay is performed using broth cultures (18-24 hours) of stool specimens placed in microwells coated with rabbit polyclonal anti-Shiga toxin 1 and anti-Shiga toxin 2. In the processing, horseradish peroxidase enzyme conjugate and substrate tetramethylbenzidine (TMB) are added and the developed yellow color is read with a spectrophotometer. Specimens with indeterminate results are repeat tested after overnight incubation in a broth culture.(O'Brien AD, Holmes RK: Shiga and Shiga-like toxins. Microbiol Rev 1987;51:206-220)

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 Saturday

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 3 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

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

Jacksonville

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.

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.

87427

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
ECOLI Shiga Toxin E. coli Ag, F 82299-9
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.
ECOLI Shiga Toxin E. coli Ag, F 82299-9

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 | Create a 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