Public Health Division

Lab Test Details

STEC Culture
Updated	4/1/2025
Search Terms	Shiga Toxin-producing E. coli; Entero Hemorrhagic E. coli; Vero Toxin-producing E. coli; E. coli serotyping
How to Order	On the General Microbiology Test Request Form (OHA0060), in the "Enterics" section, check the "Culture" box in the "Shiga toxin producing E. coli" row. If submitting an isolate specifically for an E. coli O157 ID follow the Test Menu instructions for E. coli O157 Identification. If previous testing was conducted using a culture-independent diagnostic test (CIDT), in the Specimen/Isolate Information section, for "Was an original test performed on a CIDT platform?" select "Yes" and attach your laboratory's result reports.
Availability	All clients
Performed	Daily on regular business days
Time to Reporting	For isolates and original material submitted, within 7 working days after receipt of specimen Preliminary report will be sent upon isolate confirmation, followed by a final report for serotype.
Public Health Data	De-identified data from sequencing foodborne pathogenic bacteria are submitted to the national repository bank, NCBI, and also shared with the Centers of Disease Control and Prevention, PulseNet, as part of genomic surveillance and epidemiological data sharing.
CPT Code

Specimen Collection Details
Collection	Submit stool specimen collected in GN broth (preferred) or Cary Blair transport media. Specimens must be collected prior to initiation of antimicrobials. Within two hours of collection, transfer stool specimen into Cary Blair stool transport system. Specimens must be submitted in Enteric Pathogen Transport (EPT) media (e.g., Cary Blair). Rectal swab in EPT media acceptable for specimens from infant patients.
Optimal Volume	5 gm solid stool or 5 ml liquid stool
Minimum Volume	2 gm solid stool or 2 ml liquid stool
Handling	GN Broth: Seal tube, place in sealed transport bag. Store specimens at room temperature pending transport. Cary Blair: Seal tube, place in biohazard transport bag. Store specimens at refrigerated temperatures (2-8°C) pending transport. For all specimens: Do not freeze; avoid extreme heat.
Transport	GN Broth: Transport specimens to maintain ambient temperatures during transport. Cary Blair: Package specimens with fully frozen ice packs to maintain refrigerated temperatures during transport. For all specimens: Specimens must be received at OSPHL within 4 calendar days of collection and transfer into media. Do not collect or transport for receipt at the OSPHL on a state holiday. Sample integrity may be compromised.
Rejection Criteria	Specimens are subject to the requirements of the OSPHL Specimen Submission Policy (pdf).
Comments	Sample integrity may be compromised if received at the OSPHL on a state holiday. Avoid sending samples for receipt at the laboratory on a state holiday. Original material submitted for testing is retained for 2 calendar days after receipt at the laboratory. For additional information or assistance, please contact the OSPHL at 503-693-4100.

Method Details
Methodology	Multiplex RT-PCR for Shiga Toxin detection, biochemical and serological identification
Performance Specifications	Biochemical and serological identification - N/A Multiplex RT-PCR for Shiga Toxin detection: Accuracy: 100% for isolates 98.8% for broths Sensitivity: 100% for isolates 98.4% for broths Specificity 100% for isolates 93.3% for broths Limit of Detection (LOD) Target genes: stx1 = 10 genome copies stx2 = 10 genome copies eae = 10 genome copies

Change Log
4/1/2025	Updated Search Terms; How to Order; Public Health Data; Collection; Handling; Transport; Rejection Criteria
5/2/2023	Added Public Health Data section