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Stool Culture

Test Number 008144
Test number copied
CPT 87045; 87046; 87427
Synonyms
  • Culture, Stool, Comprehensive
  • Enteric Pathogens Culture, Routine
  • Feces Culture, Routine
  • Routine Culture, Stool

Test Details

Methodology

Aerobic culture on selective media; detection of EHEC Shiga-like toxins by enzyme immunoassay (EIA)

Result Turnaround Time

3 - 5 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Related Documents

For more information, please view the literature below.

Microbiology Specimen Collection and Transport Guide

Test Includes

Culture; isolation and identification (at an additional charge) of Salmonella, Shigella, and Campylobacter, and detection of enterohemorrhagic E coli (EHEC) Shiga toxin by EIA. If culture results warrant, susceptibility testing (additional charges/CPT code[s] may apply) may be performed. CPT coding for microbiology and virology procedures often cannot be determined before the culture is performed. Requests with only a written order and no test number indicated will be processed according to Default Testing for Routine Microbiology.

Use

Detect bacterial pathogenic organisms in the stool; diagnose typhoid fever, enteric fever, bacillary dysentery, Salmonella infection.

Indications for stool culture include:1

• Bloody diarrhea

• Fever

• Tenesmus

• Severe or persistent symptoms

• Recent travel to a third world country

• Known exposure to a bacterial agent

• Presence of fecal leukocytes

Special Instructions

Specify specific pathogen if not Salmonella, Shigella, Campylobacter, or enterohemorrhagic E coli (EHEC). Check expiration date of transport; do not use expired devices.

Fecal specimens for different tests often need different transport containers and different transport conditions (eg, frozen, raw stool). Specimens should be portioned out to separate devices of each type for each test requested before sending to the laboratory. Stool for bacterial culture and enterohemorrhagic E coli Shiga toxin by EIA should be submitted in the C&S transport vial. Only a thumbnail-size portion of stool, about 1 g or 1 mL, should be added to the vial. Overfilling the vial will reduce recovery of stool pathogens.

Specimens from sources, such as genital, stool, urine, and upper and lower respiratory specimens, cannot be cultured under the aerobic bacterial culture test number. If specimens are incorrectly submitted with an order for aerobic bacterial culture, the laboratory will process the specimen for the test based on the source listed on the request form. The client will not be telephoned to approve this change, but the change will be indicated on the report.

Limitations

Yersinia sp and Vibrio parahaemolyticus will not be isolated unless specifically requested; these will each be done with an additional charge. These organisms are fastidious and have very specific requirements for growth.

Contraindications

A rectal swab culture is not as effective as a stool culture for detection of the carrier state.

Footnotes

1. Bishop WP, Ulshen MH. Bacterial gastroenteritis. Pediatr Clin North Am. 1988 Feb; 35(1):69-87 (review). 3277134
2. DuPont HL. Subacute diarrhea. To treat or to wait? Hosp Pract. 1989 Mar 30, 24(3A):111-118. 2494199
3. Clements D, Ellis CJ, Allan RN. Persistent shigellosis. Gut. 1988 Sep; 29(9):1277-1278. 3058558
4. Finkelstein JA, Schwartz JS, Torrey S, Fleisher GR. Common clinical features as predictors of bacterial diarrhea in infants.Am J Emerg Med. 1989 Sep; 7(5):469-473. 2757712
5. Cohen MB. Etiology and mechanisms of acute infectious diarrhea in infants in the United States. J Pediatr. 1991 Apr; 118(4 Pt 2):S34-S39. 2007955
6. Bartlett JG. Antibiotic-associated diarrhea. Clin Infect Dis. 1992 Oct; 15(4):573-581. 1420669

References

DeWitt TG. Acute diarrhea in children. Pediatr Rev. 1989 Jul; 11(1):6-12. 2664748
Farmer RG. Infectious causes of diarrhea in the differential diagnosis of inflammatory bowel disease. Med Clin North Am. 1990 Jan; 74(1):29-38. 2404179
Gavin PJ, Thomson RB. Diagnosis of enterohemorrhagic Escherichia coli infection by detection of Shiga toxins. Clin Microbiol Newslet. 2004; 26:49-54.
Guerrant RL. Nausea, vomiting, and noninflammatory diarrhea. In: Mandell GL, Douglas RG Jr, Bennett JE, eds. Principles and Practice of Infectious Diseases. 3rd ed. New York, NY: Churchill Livingstone;1990: 851-863.
Guerrant RL, Hughes JM, Lima NL, Crane j. Diarrhea in developed and developing countries: Magnitude, special settings, and etiologies. Rev Infect Dis. 1990 Jan-Feb; 12(Suppl 1):541-550. 2406855
Pickering LK. Therapy for acute infectious diarrhea in children. J Pediatr. 1991 Apr; 118(4 Pt 2):S118-S128. 2007952

Custom Additional Information

In enteric fever caused by Salmonella typhi, S choleraesuis, or S enteritidis, blood culture may be positive before stool cultures, and blood cultures are indicated early; urine cultures may also be helpful.

Diarrhea is common in patients with the acquired immunodeficiency syndrome (AIDS). It is frequently caused by the classic bacterial pathogens as well as unusual opportunistic bacterial pathogens and parasitic infestation. (Giardia, Cryptosporidium, and Entamoeba histolytica frequently reported.) Cryptosporidium, Isospora, and Pneumocystis can occur with AIDS. Rectal swabs are useful for the diagnosis of Neisseria gonorrhoeae and Chlamydia infections. AIDS patients are also subject to cytomegalovirus, Salmonella, Campylobacter, Shigella, C difficile, herpes, and Treponema pallidum gastrointestinal tract involvement.

Diarrhea Syndromes Classified by Predominant Features

Syndrome

(Anatomic Site)

Features

Characteristic Etiologies

Gastroenteritis (stomach)

Vomiting

Rotavirus

Norwalk virus

Staphylococcal food poisoning

Bacillus cereus food poisoning

Enteritis

(small bowel)

Watery diarrhea

Large-volume stools, few in number

Enterotoxigenic Escherichia coli

Vibrio cholerae

Any enteric microbe

Inflammatory bowel disease

Dysentery, colitis (colon)

Small-volume stools containing blood and/or mucus and many leukocytes

Shigella

Campylobacter

Salmonella

Invasive E coli

Plesiomonas shigelloides

Aeromonas hydrophila

Vibrio parahaemolyticus

Clostridium difficile

Entamoeba histolytica

Inflammatory bowel disease

In acute or subacute diarrhea, three common syndromes are recognized: gastroenteritis, enteritis, and colitis (dysenteric syndrome). With colitis, patients have fecal urgency and tenesmus. Stools are frequently small in volume and contain blood, mucus, and leukocytes. External hemorrhoids are common and painful. Diarrhea of small bowel origin is indicated by the passage of few large volume stools. This is due to accumulation of fluid in the large bowel before passage. Leukocytes indicate colonic inflammation rather than a specific pathogen. Bacterial diarrhea may be present in the absence of fecal leukocytes and fecal leukocytes may be present in the absence of bacterial or parasitic agents (ie, idiopathic inflammatory bowel disease).2 See table. Although most bacterial diarrhea is transient (1 to 30 days) cases of persistent symptoms (10 months) have been reported. The etiologic agent in the reported case was Shigella flexneri diagnosed by culture of rectal swab.3 In infants younger than one year of age, a history of blood in the stool, more than 10 stools in 24 hours, and temperature greater than 39°C have a high probability of having bacterial diarrhea.4,5 Diarrhea is also a common side effect of long-term antibiotic treatment. Although often associated with Clostridium difficile, other bacteria and yeasts have been implicated.6

Specimen Requirements

Specimen

Stool or rectal swab

Volume

1 g, 1 mL, or one swab in stool C&S transport vial (usual bacterial swab transport is not acceptable although the swab may be used)

Container

Stool culture transport vial is required; diapers are not acceptable. Culture collection swab may be used to collect rectal swabs or a swab of fecal material, then swab should be placed in stool culture transport vial (Para-Pak® C&S orange).

Collection Instructions

A single stool specimen cannot be used to rule out bacteria as a cause of diarrhea. It is recommended that two or three stool specimens, collected on separate days, be submitted to increase the probability of isolating a bacterial pathogen. Hospitalized patients who develop diarrhea while hospitalized and more than 72 hours after admission should be tested for Clostridium difficile by detection of either toxin A and/or toxin B.

Studies have shown that patients who did not have gastroenteritis or other GI symptoms on admission are unlikely to have diarrheal illness due to Salmonella, Shigella, Campylobacter, or enterohemorrhagic E coli.

Stool: Specimen should be collected in sterile bedpan, not contaminated with urine, residual soap, or disinfectants. Those portions of stool that contain pus, blood, or mucus should be transferred to a sterile specimen container.

Rectal swab: Pass swab beyond anal sphincter, carefully rotate, and withdraw. Swabbing of lesions of rectal wall or sigmoid colon during proctoscopy or sigmoidoscopy is preferred.

Duodenal or sigmoid aspirate: Specimen should be collected by a physician trained in this procedure.

Stool specimen can be divided for other types of cultures by the laboratory. Miscellaneous tests and ova and parasites tests should be split into appropriate containers and transport devices prior to shipping to the laboratory.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Specimen received in grossly leaking transport container; diapers; dry specimen; specimen submitted in fixative or additive; specimen received in expired transport media or incorrect transport device; inappropriate specimen transport conditions (not in a C&S vial or in an overfilled C&S vial); specimen received after prolonged delay in transport (usually more than 72 hours); specimen stored or transported frozen; wooden shaft swab in transport device; unlabeled specimen or name discrepancy between specimen and request label

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
008144 Stool Culture 82305-4 008722 Salmonella/Shigella Screen 43371-4
008144 Stool Culture 82305-4 180141 Campylobacter Culture 6331-3
008144 Stool Culture 82305-4 180935 E coli Shiga Toxin EIA 21262-1
Order Code008144
Order Code NameStool Culture
Order Loinc82305-4
Result Code008722
Result Code NameSalmonella/Shigella Screen
UofM
Result LOINC43371-4
Order Code008144
Order Code NameStool Culture
Order Loinc82305-4
Result Code180141
Result Code NameCampylobacter Culture
UofM
Result LOINC6331-3
Order Code008144
Order Code NameStool Culture
Order Loinc82305-4
Result Code180935
Result Code NameE coli Shiga Toxin EIA
UofM
Result LOINC21262-1
Reflex Table for Salmonella/Shigella Screen
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 997871 Result 997141 Result 1 6463-4
Reflex 1
Order Code997871
Order NameResult
Result Code997141
Result NameResult 1
UofM
Result LOINC6463-4
Reflex Table for Salmonella/Shigella Screen
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 997871 Result 997142 Result 2 6463-4
Reflex 1
Order Code997871
Order NameResult
Result Code997142
Result NameResult 2
UofM
Result LOINC6463-4
Reflex Table for Salmonella/Shigella Screen
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 997871 Result 997143 Result 3 6463-4
Reflex 1
Order Code997871
Order NameResult
Result Code997143
Result NameResult 3
UofM
Result LOINC6463-4
Reflex Table for Salmonella/Shigella Screen
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 997871 Result 997144 Result 4 6463-4
Reflex 1
Order Code997871
Order NameResult
Result Code997144
Result NameResult 4
UofM
Result LOINC6463-4
Reflex Table for Salmonella/Shigella Screen
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 997871 Result 997145 Antimicrobial Susceptibility 23658-8
Reflex 1
Order Code997871
Order NameResult
Result Code997145
Result NameAntimicrobial Susceptibility
UofM
Result LOINC23658-8
Reflex Table for Campylobacter Culture
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 080172 Result 080173 Result 1 6463-4
Reflex 1
Order Code080172
Order NameResult
Result Code080173
Result NameResult 1
UofM
Result LOINC6463-4
Reflex Table for Campylobacter Culture
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 080172 Result 080174 Result 2 6463-4
Reflex 1
Order Code080172
Order NameResult
Result Code080174
Result NameResult 2
UofM
Result LOINC6463-4
Reflex Table for Campylobacter Culture
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 080172 Result 080175 Result 3 6463-4
Reflex 1
Order Code080172
Order NameResult
Result Code080175
Result NameResult 3
UofM
Result LOINC6463-4
Reflex Table for Campylobacter Culture
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 080172 Result 080177 Result 4 6463-4
Reflex 1
Order Code080172
Order NameResult
Result Code080177
Result NameResult 4
UofM
Result LOINC6463-4
Reflex Table for Campylobacter Culture
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 080172 Result 080178 Antimicrobial Susceptibility 23658-8
Reflex 1
Order Code080172
Order NameResult
Result Code080178
Result NameAntimicrobial Susceptibility
UofM
Result LOINC23658-8