The E.coli O157:H7 Rapid Test is a one step coloured chromatographic immunoassay for the qualitative detection of Escherichia coli O157 in stool samples.
The detection of E. coli O157:H7 showed a 100% of concordance in sensitivity.
Infection with Escherichia coli O157:H7 (Enterohemorrhagic Escherichia coli) presents with a wide spectrum of clinical manifestations, including asymptomatic carriage, nonbloody diarrhea, hemorrhagic colitis, the hemolytic-uremic syndrome, and thrombotic thrombocytopenic purpura. Not only is E. coli O157:H7 an important agent for hemorrhagic colitis, it is also one of the leading causes of bacterial diarrhea. Transmission of E. coli O157:H7 is primarily food-borne. Undercooked meat is the most common culprit, dairy products and secondary person-to-person spread are also important. The organism produces at least two Shiga-like toxins. These toxins are thought to have direct pathogenic significance in E. coli O157:H7 infection. This infection is usually diagnosed from a positive stool culture, from the presence of Shiga toxins, or both. Timely collection (within 7 days of illness onset) of a stool sample for culture is imperative for a high recovery rate. E. coli O157:H7 Rapid Test test provides a rapid detection of E. coli O157:H7 directly from the stool samples.
Principle Of The Test
The E. coli O157:H7 Rapid Test is a qualitative immunochromatographic assay for the determination of E. coli O157:H7 in stool samples. The membrane is pre-coated with mouse polyclonal antibodies, on the test band region, to recognize this serotype (polyclonal antibodies against O157:H7 antigens). During testing, the sample is allowed to react with the coloured conjugate (anti-E. coli O157:H7 antibodies-red microspheres) which was pre-dried on the test. The mixture then moves upward on the membrane by capillary action. As the sample flows through the test membrane, the coloured particles migrate. In the case of a positive result the specific antibodies present on the membrane will capture the coloured conjugate (result region). The mixture continues to move across the membrane to the immobilized antibody placed in the control band region, a GREEN coloured band always appears. The presence of this GREEN band serves as 1) verification that sufficient volume is added, 2) that proper flow is obtained and 3) as an internal control for the reagents.