Development of rapid detection of vibrio cholera in immunomagnetic enriched samples by mab-based dot-blot elisa

Abstract

Ab-reacted beads have been produced by reacting goat anti-rabbit immunoglobulin G (IgG) coated superparamagnetic beads (BioMag) with 100 mg/ml of Vibrio cholerae (Vc)-specific rabbit Igs. The beads were used to capture Vc or its antigensin food samples. The antigens (Ag) on the Ag-captured beads were then detected by MAb-based dot-blot ELISA. This immunomagnetic enrichment (IME) was able to detect V. cholerae suspended in the food samples as low as 106 cfu/ml. By using this IME/MAb-based dot-blot ELISA we could detect V. cholerae in 100% (all 50 samples) of artificially seeded food samples, whereas the conventional culture method showed only 32% positive. Enrichment of the bacteria by IME prior to conventional culturing increased percent positivity from 20.59% (7 of 34 samples) to 52.94% (18 of 34 samples) or about 2.5 times. The method would be therefore useful for large scale screening, especially in the endemic areas because the method is simple, rapid and gives not much waste products as those derived from conventional culture method.