INTENDED USE

The Clostridium Difficile Toxin A Antigen Rapid Test Kit is a lateral flow chromatographic immunoassay for the qualitative detection of Clostridium Difficile Toxin A in human Fecal Specimen. It is suitable for the auxiliary diagnosis of Clostridium Difficile Toxin A infection.

SUMMARY

Clostridium Difficile(C.difficile), a Gram-positive spore bearing anaerobic bacterium is the major aetiological agent of diarrhoea and colitis associated with antibiotics.C.difficile is the most common cause of health care-associated diarrhoea in developed coutries and is a major source of nosocomial morbidity and mortality worldwide.
Diease due to C.difficile develops when the organism is allowed to proliferate in the colon,most commonly after antibiotic use has eliminated competing flora,C.difficile can release two high-molecular-weight toxins,toxin A and toxin B,which are responsible for the clinical manifestations,which range from mild,self-limited watery diarrhoea to fulminant pseudomembranous colitis,toxic megacolon and death.
The toxigenic culture(TC) is used as the gold standard technique to determine Clostridium difficile infection.This method consists in culture and isolation of C.difficile from faeces,followed by toxin testing of the isolate,a labour-intensive assay to obtain a result.

PRINCIPLE

The Clostridium Difficile Toxin A Antigen Rapid Test Kit is a lateral flow chromatographic immunoassay. The test cassette consists of: 1) a burgundy colored conjugate pad containing recombinant antigen conjugated with colloid gold (monoclonal mouse anti-Clostridium Difficile Toxin A antibody conjugates) and rabbit IgG-gold conjugates, 2) a nitrocellulose membrane strip containing test band (T bands) and a control band (C band). The T band is pre-coated with monoclonal mouse anti-Clostridium Difficile Toxin A antibody for the detection of Clostridium Difficile Toxin A antigen, and the C band is pre-coated with goat anti rabbit IgG. When an adequate volume of test specimen is dispensed into the sample well of the test cassette, the specimen migrates by capillary action across the cassette.

Clostridium Difficile Toxin A if present in the specimen will bind to the monoclonal mouse anti-Clostridium Difficile Toxin A antibody conjugates. The immunocomplex is then captured on the membrane by the pre-coated mouse anti-Clostridium Difficile Toxin A antibody, forming a burgundy colored T band, indicating a Clostridium Difficile Toxin A antigen positive test result. Absence of test band (T) suggests a negative result. The test contains an internal control (C band) which should exhibit a burgundy colored band of the immunocomplex of goat anti rabbit IgG/rabbit IgG-gold conjugate regardless of the color development on any of the test bands. Otherwise, the test result is invalid, and the specimen must be retested with another device.