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E. coli O157 culture

Item Value
Approval req'd? No
Available Stat? No
Test code P157
Performed by Microbiology
In House Availability Set up daily, all shifts.
Method Culture
Collection Instructions Submit unpreserved stool to laboratory within 3 hours of collection.

If specimen will be submitted to the laboratory more than 3 hours after collection, or after 11 pm when Microbiology is closed, submit stool in C & S (Cary & Blair) Medium. Add stool to red line on vial and mix well with spoon.

C & S (Cary & Blair) Medium is available from Material Services . Outpatients can obtain these from the laboratories' draw stations.
For patient collect samples, order PMM 68902 C & S Medium Cary Blair 2805-05-WB (with bag and instructions).
PMM 49206 C & S Medium 2805-05 (without bag or instructions) also available.

Container type Urine cup or C & S (Cary & Blair) transport medium
Amount to Collect 5 mL
Sample type Stool
Preferred volume 5 mL
Min. Volume Fresh stool : 0.5 mL or size of pea, Stool in C & S (Cary & Blair) transport medium: 5 mL
UCSF Rejection Criteria Unpreserved stool received > 3 hours after collection. More than two samples per day.
Processing notes If < 5mL stool received, add 3 parts Cary & Blair medium to 1 part stool.
Normal range
Critical value Inpatient results only. After hours outpatient results will be phoned the following morning.
Positive for E. coli O157
Synonyms Shiga toxin; Toxigenic E. coli; Enteropathogenic E coli
Stability Unpreserved 3 hours, preserved 1 week
Turn around times 1-3 days
Additional information Bacterial Culture-Stool, E. coli O157 Culture, and Shiga Toxin Assay are orderable as a panel in Apex (Community-Acquired Diarrhea Testing Panel). If testing for individual components of this panel is desired, please contact the microbiology lab.

If bacteria are detected that are not normal mixed flora they are automatically identified and susceptibility testing is performed if appropriate.

Susceptibility testing may be omitted upon request when sample is submitted for testing.

Culture for E. coli O157 and Shiga Toxin Assay is automatically performed on stools submitted for bacterial culture, and are billed separately.
CPT coding 87046
LOINC code 10851-4
Last Updated 3/27/2017 11:18:07 AM
Entry Number 328
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