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HelpTest Code E157C Escherichia coli O157:H7 Culture, Feces
Additional Testing Requirements
In some cases, local public health requirements may impact Mayo Clinic Laboratories clients, requiring, for example, submission of isolates to public health laboratories. Clients should familiarize themselves with local requirements and are responsible for submitting isolates to appropriate public health laboratories. Clients can obtain isolates of Escherichia coli O157:H7 species recovered from specimens submitted to Mayo Clinic Laboratories by calling 800-533-1710 as soon as possible after reporting (to ensure viability of the bacterium).
Shipping Instructions
Specimen must arrive within 96 hours of collection.
Necessary Information
Specimen source is required.
Specimen Required
Patient Preparation: Patient should not use barium or bismuth for 7 to 10 days before specimen collection.
Supplies: Culture and Sensitivity Stool Transport 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 or Para-Pak C and S)
Specimen Volume: Representative portion of fecal specimen
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.
3. Place vial in a sealed plastic bag.
Useful For
Determining whether Escherichia coli O157:H7 may be the cause of diarrhea
Reflexive testing for Shiga toxin and/or E coli O157:H7 nucleic acid amplification test-positive feces
This test is generally not useful for patients hospitalized more than 3 days because the yield from specimens from these patients is very low, as is the likelihood of identifying a pathogen that has not been detected previously.
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| GID | Bacteria Identification | No, (Bill Only) | No |
| ISAE | Aerobe Ident by Sequencing | No, (Bill Only) | No |
| REFID | Additional Identification Procedure | No, (Bill Only) | No |
| EC | Serologic Agglut Method 2 Ident | No, (Bill Only) | No |
| RMALD | Ident by MALDI-TOF mass spec | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, the reflex tests may be performed at an additional charge.
For more information see Laboratory Testing for Infectious Causes of Diarrhea.
Special Instructions
Reporting Name
E. coli O157:H7 Culture, FSpecimen Type
FecalSpecimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Fecal | Ambient (preferred) | 4 days | |
| Refrigerated | 4 days |
Reject Due To
| Unpreserved feces ECOFIX preservative Formalin or PVA fixative |
Reject |
Reference Values
No growth of Escherichia coli O157:H7
Day(s) Performed
Monday through Friday
Report Available
2 to 4 daysSpecimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
87046-Escherichia coli O157:H7 Culture, Stool-with isolation and preliminary examination
87077-Bacteria Identification (if appropriate)
87153-Aerobe Ident by Sequencing (if appropriate)
87077-Additional Identification Procedure (if appropriate)
87147-Serologic Agglut Method 2 Ident (if appropriate)
87077-Ident by MALDI-TOF mass spec (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| E157C | E. coli O157:H7 Culture, F | 10851-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| E157C | E. coli O157:H7 Culture, F | 10851-4 |