Clostridium difficile is an anaerobic gram-positive spore-forming bacillus. C. difficile is transmitted through the fecal-oral route. Clostridium difficile is the principal pathogen related to antibiotic associated diarrhea and/or pseudomembranous colitis in hospitalized patients. Mature colonic bacterial flora in a healthy adult is generally resistant to C. difficile colonization. However, if the normal colonic flora is altered, resistance to colonization is lost. Thus, any factor associated with alteration of the normal enteric flora increases the risk of C. difficile colonization after exposure to antibiotics, especially those with broad-spectrum activity such as penicillins, cephalosporins and clindamycin. C. difficile can release two high-molecular-weight toxins, toxin A and toxin B, which are responsible for the clinical manifestations. Clostridium difficile Glutamate Dehydrogenase (GDH) is an enzyme produced in large quantities by all toxigenic and non-toxigenic strains, making it an excellent marker for the organism.
C. difficile Ag Rapid test is a qualitative immunoassay for the detection of GDH antigen in human feces samples. The membrane is pre-coated with antibodies against GDH antigen on the test line region. During testing, the sample reacts with the red colored particles coated with anti-GDH antibodies which were pre-dried on the test strip. The mixture moves upward on the membrane by 2 capillary action. As the sample flows through the test membrane, the colored particles conjugate migrate. In the case of a positive result the specific antibodies present on the membrane will react with the conjugate and generate one red colored line. The mixture continues to move across the membrane to the immobilized antibody places in the control band region. A green colored band always appears in the control line (second line) and serves as verification that sufficient volume was added, that proper flow was obtained and as an internal control for the reagents.
Figure 1. Assay procedure (collected stool sample)
Figure 2. Interpretation of results
Reagents And Materials Provided
1. Rapid C. difficile Ag Cards
2. Instructions for use
3. Specimen collection vials with buffer