Cepheid GeneXpert Clostridiodes (Clostridium) difficile by PCR
POWERCHART ORDER – Clostridium difficile by PCR , Cdiff by PCR , Cdiff-by PCR
Useful For
The Cepheid Xpert® C. difficile/Epi Assay is a qualitative in vitro diagnostic test for rapid detection of toxin B gene sequences and for presumptive identification of 027/NAP1/BI strains of toxigenic Clostridium difficile from unformed ( Bristol Chart 6 & 7 liquid or soft) stool specimens collected from patients suspected of having C. difficile infection (CDI).
Presumptive identification of 027/NAP1/BI strains of C. difficile is by detection of binary toxin (CDT) gene sequences and the single base pair deletion at nucleotide 117 in the tcdC gene. The tcdC gene encodes for a negative regulator in C. difficile toxin production.
Method Name
Polymerase Chain Reaction (PCR)
Aliases
Clostridium Difficile By Pcr, Clostridium,pcr,clostridioides,cdiff,
Specimen Type
Unformed (diarrheal) Stool
Specimen Required
Obtain stool within 6 hours of order. diarrheal (unformed) stool into a clean, leak proof container
Specimen Minimum Volume
1 mL or 1 gram
Specimen Stability Information
- Specimens are stable refrigerated at 2-8 C for 5 days
- Specimens are stable when stored at room temperature for 24 hours.
- Deliver to the lab as soon as possible.
- *NOTE* Specimens that do not meet the above criteria will be rejected.
Rejected Due To
- Specimens received refrigerated at 2-8 C after 5 days
- Specimens received after 24 hours at room temperature.
Special Instructions
We follow recommendations from the SHEA-ISDA “Clinical Practice Guidelines for Clostridium difficile in Adults:2010”
- Testing of C. diff for it’s toxin should be performed only on diarrheal (unformed) stool, unless ileus due to C. difficile is suspected.
- Testing of stool from asymptomatic patients is not clinically useful including use as a test of cure. It is not recommended except for epidemiological studies.
- Repeat testing during the same episode of diarrhea is of limited use and should be discouraged.
- Samples that are not diarrheal or unformed will not be tested and canceled with the following message. “Testing for C. diff by PCR canceled. PCR testing will be performed only on diarrheal (unformed) stool.
- Testing on formed stool specimens will be done only if specifically requested for a valid clinical condition i.e. ileus.”
- 027-NAP1-BI results are NOT intended to guide treatment of C. difficle infections.
- This assay has not been evaluated for patients under two years of age and will be sent to a reference lab for testing.
Performing Laboratory
Glens Falls Hospital Microbiology Laboratory
Reference Values
Toxigenic Clostridium difficile – Negative 027-NAP1-B1 Presumptive – Negative
Day(s) and Time(s) Performed
- 7am-9pm
- 7 days per week
Analytical Time
1-3 hours turnaround time
Specimen Retention Time
72 hours
Analytical Time
1-3 hours turnaround time