Shiga Toxin, Molecular Detection, PCR, Feces
Use
Sensitive, specific, and rapid detection of the presence of Shiga toxin-producing organisms such as Escherichia coli O157:H7 and Shigella dysenteriae type 1 in stool. This test is crucial for diagnosing infections caused by Shiga toxin-producing bacteria, which can lead to severe gastrointestinal symptoms and complications like hemolytic uremic syndrome (HUS). Early detection allows for appropriate clinical management, primarily supportive, as antimicrobial therapy is contraindicated.
Special Instructions
In some cases, local public health requirements may impact Mayo Clinic Laboratories (MCL) clients and require additional testing on specimens with positive test results. MCL recommends clients retain an aliquot of each specimen for potential additional testing within 96 hours of collection. Clients must contact MCL to arrange such testing.
Limitations
The test detects Shiga toxin-producing E. coli and Shigella dysenteriae type 1. It does not detect all subtypes of Shiga toxins, specifically stx2e or stx2f, which are rarely associated with human disease. Interfering substances in the fecal specimen can affect assay accuracy, and results should be interpreted in conjunction with clinical and epidemiological findings. Repeat testing should not be performed on specimens collected less than 7 days apart.
New York Approved
Methodology
PCR-based (Real-Time PCR)
Biomarkers
LOINC Codes
- 80679-4
- 31208-2
- 80679-4
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Stool
Volume
5 mL
Minimum Volume
1 mL
Container
Commercially available transport system specific for recovery of enteric pathogens from fecal specimens (15 mL of nonnutritive transport medium containing phenol red as a pH indicator, either Cary-Blair or Para-Pak C and S)
Collection Instructions
1. Collect fresh fecal specimen and submit in container with transport medium. 2. Within 2 hours of collection, place feces in preservative.
Storage Instructions
Ambient (preferred) 7 days/Refrigerated 7 days
Causes for Rejection
Reject if: Formed feces, feces in gel transport medium, feces in EcoFix preservative, feces in formalin, feces in PVA fixative, or preserved feces received frozen.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |
| Frozen | 7 days |