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HelpTest Code CDIF Clostridioides difficile Culture, Varies
Useful For
Providing an isolate suitable for antimicrobial susceptibility testing
Highlights
Culture provides definitive evidence of the presence of the bacterium, Clostridioides difficile, in feces, providing an isolate for antimicrobial susceptibility testing.
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| ANAID | Anaerobe Ident | No, (Bill Only) | No |
| RMALA | Id MALDI-TOF Mass Spec Anaerobe | No, (Bill Only) | No |
| ISAN | Anaerobe Ident by Sequencing | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, the reflex tests may be performed at an additional charge.
Method Name
Conventional Culture Technique
Reporting Name
C. difficile CultureSpecimen Type
VariesOrdering Guidance
If susceptibilities are also desired, order CDIFS / Clostridioides (Clostridium) difficile Culture with Antimicrobial Susceptibilities, Varies
This is not the preferred diagnostic test for Clostridioides difficile. For routine diagnostic testing, order CDPCR / Clostridioides difficile Toxin, PCR, Feces.
Additional Testing Requirements
If susceptibility testing is needed; also order MMLSA / Antimicrobial Susceptibility, Anaerobic Bacteria, MIC, Varies. Susceptibility testing, when ordered, would routinely include metronidazole and vancomycin. If susceptibilities are not appropriate and will not be performed, MMLSA will be canceled.
Shipping Instructions
Necessary Information
Specimen source is required.
Specimen Required
Submit only 1 of the following specimens:
Patient Preparation: Patient should not use antacids, barium, bismuth, antidiarrheal medication, zinc oxide paste, Vagisil cream or oily laxatives prior to specimen collection.
Preferred:
Specimen Type: Preserved feces
Supplies: Culture and Sensitivity Stool Transport Vial (T058)
Container/Tube: Commercially available transport system specific for recovery of enteric pathogens from fecal specimens (15 mL of non-nutritive transport medium containing phenol red as a pH indicator, either Cary-Blair or Para-Pak C and S)
Specimen Volume: Representative portion of feces; 5 mL
Collection Instructions:
1. Collect 1 gram or 5 mL fresh fecal specimen and submit in container with transport medium.
2. Place feces in preservative within 2 hours of collection.
Additional Information: Only diarrheal (ie, unformed) feces should be tested. Testing formed feces for Clostridioides difficile is generally not clinically indicated.
Specimen Stability Information: Ambient (preferred) 96 hours/Refrigerated 96 hours/Frozen 7 days
Acceptable:
Specimen Type: Unpreserved feces
Supplies:
-Stool container, Small (Random), 4 oz (T288)
-Stool Collection Kit, Random (T635)
Container/Tube: Stool container
Specimen Volume: Representative portion of feces
Collection Instructions: Collect fresh feces and submit representative sample in stool container.
Additional Information: Only diarrheal (ie, unformed) feces should be tested. Testing formed feces for Clostridioides difficile is generally not clinically indicated.
Specimen Stability Information: Ambient (preferred) 72 hours/Frozen 7 days
Specimen Type: Fresh tissue or biopsy
Sources: Colon
Supplies: Anaerobe Transport Tube (T588)
Specimen Volume: Entire collection, 1 to 2 cm(3)
Collection Instructions: Aseptically collect 1 to 2 cm(3) piece of tissue whenever possible. In general, a larger piece of tissue is preferred. Submit in an anaerobic transport tube.
Specimen Stability Information: Ambient 72 hours
Specimen Minimum Volume
Stool: 1 g or 5 mL
Tissue: 5 mm(3)
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | ||
Reject Due To
| Fecal swab Specimen in Ecofix |
Reject |
Clinical Information
Clostridioides difficile (formerly Clostridium difficile) can cause diarrhea and may cause pseudomembranous colitis. Overgrowth of toxin-producing C difficile in the colon leads to the production of toxins A and/or B by the organism and consequent diarrhea. C difficile infection should be suspected in patients with symptoms of diarrhea with risk factors such as current or recent use of antibiotics, a history of C difficile infection, current or recent hospitalization or placement in a nursing home or long-term care facility, age older than 65 years, gastric acid suppression, etc. C difficile infection is the most common cause of diarrhea in hospitalized patients and may lead to serious complications, including sepsis, bowel perforation, and increased overall mortality (especially in older patients). The incidence of C difficile infection has risen in the community and in healthcare settings. While culture is not the preferred means to diagnose C difficile-associated diarrhea, culture for C difficile provides an isolate suitable for antimicrobial susceptibility testing. Note that this test does not differentiate between toxin-producing and nontoxigenic strains of C difficile.
Reference Values
No growth of Clostridioides difficile.
Interpretation
A positive result indicates the presence of viable Clostridioides difficile in feces.
A positive culture may be found with asymptomatic C difficile colonization with a toxin-producing or non-toxin-producing strain or with C difficile-associated diarrhea.
A negative result indicates the absence of C difficile growth in culture.
Cautions
The assay must be performed on fresh feces, fresh-frozen feces, or feces in transport medium. Only diarrheal (ie, unformed) feces should be tested.
Submission of more than 1 specimen for testing is not recommended.
Repeated testing during a single episode of diarrhea is not recommended.
Testing of asymptomatic patients (ie, without diarrhea) or for test of cure is not recommended.
Isolation of C difficile does not differentiate between toxin-producing and non-toxin-producing strains.
Patients may asymptomatically carry Clostridioides difficile.
Testing of colostomy, ileostomy, or colonoscopically collected specimens has not been validated.
Supportive Data
Fifty fecal specimens in Cary Blair transport media previously determined as positive for Clostridioides difficile by toxin polymerase chain reaction were subcultured directly onto CHROMagar C difficile plates. Plates were incubated under anaerobic conditions at 37° C for 24 hours in accordance with the manufacturer's recommendation. C difficile identification was performed by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) directly from bacterial colony growth on CHROMagar plates. Using this method, C difficile was identified from 47 of 50 fecal specimens, corresponding with a 94% recovery rate. Two specimens that did not yield C difficile on CHROMagar media also failed to produce growth on conventional C difficile selective media (taurochocolate, cycloserine, cefoxitin, fructose agar: TCCFA). One specimen was recovered by the TCCFA media, but not by the CHROMagar C difficile media. Organisms other than C difficile were not recovered on CHROMagar, corresponding to 100% analytical specificity.
Clinical Reference
1. Cohen SH, Gerding DN, Johnson S, et al. Clinical practice guidelines for Clostridium difficile infection in adults: 2010 update by the Society for Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of America (IDSA). Infect Control Hosp Epidemiol. 2010;31(5):431-455
2. Lawson PA, Citron DM, Tyrrell KL, Finegold SM. Reclassification of Clostridium difficile as Clostridioides difficile (Hall and O'Toole 1935) Prevot 1938. Anaerobe. 2016;40:95-99. doi:10.1016/j.anaerobe.2016.06.008
3. Oren A, Garrity GM. List of new names and new combinations previously effectively, but not validly, published. Int J Syst Evol Microbiol. 2016;66(11):4299-4305. doi:10.1099/ijsem.0.001585
Method Description
Specimens are directly inoculated onto a CHROMagar Clostridioides difficile plate, which is incubated anaerobically at 35 to 37° C for 24 hours. Plates are observed for characteristic fluorescence using ultraviolet light at 365 nm. Fluorescent colonies are identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry or 16S ribosomal RNA gene sequencing.(Unpublished Mayo method
Day(s) Performed
Monday through Sunday
Report Available
2 to 6 daysSpecimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
87081-C. difficile Culture
87076-Anaerobe Ident (if appropriate)
87076-Id MALDI-TOF Mass Spec Anaerobe (if appropriate)
87153-Anaerobe Ident by Sequencing (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CDIF | C. difficile Culture | 562-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CDIF | C. difficile Culture | 562-9 |
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.