Evaluation of immunochromatography method for rapid detection of Shigatoxin

The Shigatoxin detection kit based on the immunochromatography system is commercially available. To obtain the identification result rapidly, we devised the improved method (ICG-Imp) replaced to an original method (ICG). Modification provided that Shigatoxins extracted directly from the strains grown on TSI medium without centrifugation. ICG-Imp was compared with ICG, RPLA and PCR. Comparing with RPLA, the sensitivity, specificity, and concordance rate of Shigatoxin 1 showed 77.5, 100 and 90.5%, respectively on ICG, 93.8, 100 and 97.4%, respectively on ICG-Imp, and 100, 99.1 and 99.5%, respectively on PCR. On the other hand, the patterns of Shigatoxin 2 showed 95.3, 100 and 96.3%, respectively on ICG, 100, 100, and 100%, respectively on ICG-Imp, and 100, 100 and 100%, respectively on PCR. The time required from TSI medium to the final result are 24 h, 30-60 min, 48 h, and 6 h, respectively by ICG, ICG-Imp, RPLA, and PCR. It seems that the ICG-Imp is recommended for the identification by means of the accuracy and rapidness.