Sorted By Test Name - Mayo Medical Laboratories

CLOS
80424
CDRP
83124
Sedation has been associated with serum clonidine concentrations
greater than 1.5 ng/mL
Toxic concentration has not been established.
Test Performed By:
Medtox Laboratories, Inc.
402 W. County Road D
St. Paul, MN 55112
Clostridium difficile Culture
Reference Values:
The isolation of C. difficile from stool specimens provides a high degree of sensitivity (97%) for the
diagnosis of pseudomembranous colitis and antibiotic-associated disease. However, a positive culture may
be non-specific finding (carrier or colonization) or the isolate may be a non-toxigenic strain.
Test Performed by
Focus Diagnostics
5785 Corporate Avenue
Cypress, CA 90630-4750
Clostridium difficile Toxin, Molecular Detection, PCR
Clinical Information: Clostridium difficile is the cause of Clostridium difficile-associated diarrhea
(CDAD), an antibiotic-associated diarrhea, and pseudomembranous colitis (PMC). In these disorders
bacterial overgrowth of Clostridium difficile develops in the colon typically as a consequence of antibiotic
usage. Clindamycin and broad-spectrum cephalosporins have been most frequently associated with
CDAD and PMC, but almost all antimicrobials may be responsible. Disease is related to production of
toxin A and/or B. Treatment typically involves withdrawal of the associated antimicrobial(s) and, if
symptoms persist, orally administered and intraluminally active metronidazole, vancomycin, or
fidaxomicin. Intravenous metronidazole may be used if an oral agent cannot be administered. In recent
years, a more severe form of CDAD with increased morbidity and mortality has been recognized as being
caused by an epidemic toxin-hyperproducing strain of Clostridium difficile (NAP1 strain). Many
toxin-hyperproducing isolates also contain the binary toxin gene and are resistant quinolones. This test
does not differentiate between toxin hyperproducing and nontoxin hyperproducing strains. Traditionally,
diagnosis relied upon 1) clinical and epidemiologic features, 2) culture (which is labor intensive and time
consuming), 3) cytotoxicity assays, which are labor intensive and time consuming, and 4) toxin detection
immunoassays (which are insensitive). The described PCR assay detects the regulatory gene responsible
for production of toxins A and B (tcdC). This test is used for rapid diagnosis of CDAD and PMC enabling
prompt treatment which may reduce hospital stays for inpatients with CDAD.
Useful For: Sensitive, specific, and rapid diagnosis of Clostridium difficile-associated diarrhea and
pseudomembranous colitis
Interpretation: A positive PCR result for the presence of the gene regulating toxin production (tcdC)
indicates the presence of Clostridium difficile and toxin A and/or B. A negative result indicates the
absence of detectable Clostridium difficile tcdC DNA in the specimen, but does not rule out Clostridium
difficile infection. False-negative results may occur due to inhibition of PCR, sequence variability
underlying the primers and/or probes or the presence of Clostridium difficile in quantities less than the
limit of detection of the assay.
Reference Values:
Not applicable
Clinical References: 1. Aichinger E, Schleck CD: Nonutility of repeat laboratory testing for
Current as of January 4, 2013 7:15 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 482