Salmonella, Shigella, Campylobacter, Fecal culture, O157:H7, EHEC, Stool for E. coli, Hemorrhagic E. coli, Shiga Toxin, Enterohemorrhagic E. coli, Stool Culture
Specimen Collection Criteria
Collect: Random stool specimen, about the size of a walnut, placed in a container with Para-Pak/Cary-Blair transport medium. Specimens not in Para-Pak/Cary-Blair transport medium must be placed in a sterile collection container, refrigerated, and sent to the Laboratory immediately.
- Do not contaminate the exterior of the container with the specimen.
- Do not place toilet tissue in the container with the specimen.
- Do not contaminate the specimen with urine.
- If the patient has taken antibiotics, barium, oil, or magnesium compounds, delay the collection of stool specimens for at least 7 days.
- Rectal swabs (pediatric stool only) and stool aspirates are acceptable for stool cultures but the Shiga toxin testing can not be performed on them.
Physician Office/Draw Specimen Preparation
Stool in Para-Pak/Cary-Blair transport medium — maintain at room temperature (20-26°C or 68-78.8°F).
Stool NOT in Para-Pak/Cary-Blair transport medium — must be refrigerated (2-8°C or 36-46°F) and received in the Laboratory within 2 hours of collection – NO EXCEPTIONS.
Preparation for Courier Transport
Transport: Stool specimen in Para-Pak/Cary-Blair medium at room temperature (20-26°C or 68-78.8°F).
- Unpreserved specimens (regardless of temperature storage) received in the laboratory more than 2 hours after collection.
- Frozen specimens (preserved or unpreserved).
- Stool collected following a soap suds enema.
- Stool containing barium from a previous x-ray.
- Stool in diapers.
- Rectal swabs and endoscopy specimens are unacceptable for Shiga toxin testing.
- Stool culture on inpatients that have been hospitalized greater than three days.
- The Laboratory will only test one specimen per patient per 24 hour period.
- The Laboratory will not test more than two specimens per patient per diarrheal episode without prior consultation with one of the Microbiology Laboratory directors.
Specimen Stability for Testing:
Room Temperature (20-26°C or 68-78.8°F): 2 hours (Unpreserved)
Room Temperature (20-26°C or 68-78.8°F): 72 hours (Preserved/Para-Pak/Cary-Blair)
Refrigerated (2-8°C or 36-46°F): 2 hours (Unpreserved)
Refrigerated (2-8°C or 36-46°F): 72 hours (Preserved/Para-Pak/Cary-Blair)
Frozen (-20°C/-4°F or below): Unacceptable (Unpreserved or Preserved/Para-Pak/Cary-Blair)
Specimen Storage in Department Prior to Disposal:
Refrigerated (2-8°C or 36-46°F): 4 days
Dearborn Microbiology Laboratory
Taylor, Trenton and Wayne sent to Dearborn Microbiology Laboratory for testing.
Royal Oak Microbiology Laboratory
Farmington Hills, Grosse Pointe, and Troy sent to Royal Oak Microbiology Laboratory for testing.
Sunday – Saturday.
Preliminary results available within 1-2 days.
Final negative results available within 2 days.
Shiga toxin results available within 24 hours.
No Salmonella, Shigella, Campylobacter, Aeromonas or Plesiomonas recovered.
Negative for Shiga toxin producing E. coli.
Culture, Immunochromatographic Assay.
Salmonella, Shigella, Campylobacter, Aeromonas, Plesiomonas and Shiga toxin producing E. coli are infectious agents known to cause diarrhea. These bacteria affect patients of all ages.
Asymptomatic carriage of Campylobacter and Shigella are uncommon.
Stool cultures can facilitate the diagnosis of Aeromonas, Campylobacter, Plesiomonas Salmonella, Shigella, Vibrio and Yersinia infections. Toxin testing further assists in the detection of Shiga toxin producing enterohemorrhagic E. coli.
Campylobacter: 1-7 days or longer.
Salmonella: 6-72 hours for gasteroenteritis. 3-60 days (average 7-14 days) for enteric fever.
Shigella: 1-7 days (average of 2-4 days).
E. coli: 3-4 days (range of 1-10 days).
Transmission of these pathogenic bacteria is usually through the fecal-oral route, contaminated foods, and domestic and wild animals.
- Pillai, D.R., 2016. Fecal Culture for Aerobic Pathogens of Gastroentenitis. In: Clinical Microbiology Procedures Handbook. Procedures Handbook. 4th ed. Leber, A.L., Ed-in-Chief. ASM Press. Washington, D.C.
- Pillai, D.R., 2016. Fecal Culture for Campylobacter and Related Organisms. In: Clinical Microbiology Procedures Handbook. Leber, A.L., Ed-in-Chief. ASM Press. Washington, D.C.
- Siegel, D.L. et al, 1990. Inappropriate Testing for Diarrheal Diseases in the Hospital. JAMA, 263:979-982.
87045 (Culture), 87427x2 (Shiga Toxin). Additional charges may be incurred for identification and susceptibility testing.
LOINC: 625-4, Vibrio 6578-9, Yersinia 701-3
Microbiology Laboratory – DBN
Microbiology Laboratory – RO
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