The Prolex™ E. coli O157 Latex Test Reagent Kit is an agglutination test kit for the presumptive identification of Escherichia coli serogroup O157.

• Blue polystyrene latex particles coated with E. coli somaticc antigen
• Agglutination test kit

The blue polystyrene latex particles used in the kit are coated with an antibody against the E

Escherichia coli serotype O157:H7 is a Shiga toxin-producing pathogen.This serotype has been reported as an etiological agent in sporadic and outbreak cases of haemorrhagic colitis. It is also associated with haemolytic uraemic syndrome. Certain E. coli serotypes other than O157:H7 also produce Shiga toxin.However, the diarrhoea caused by these other serotypes is not usually bloody. Additionally, E. coli serotype O157:H7 does not ferment sorbitol, whereas most other serotypes do.Therefore, if Sorbitol MacConkey Agar is used as a primary screen, the colonies of E. coli serotype O157:H7 appear colourless (non-sorbitol-fermenting colonies [NSFC]) while colonies of the other serotypes appear characteristically pink (sorbitol-fermenting colonies [SFC]).

coli O157 somatic antigen. When these latex particles are mixed with fresh colonies of E. coli serogroup O157, the bacteria will bind to the antibody causing the latex particles to agglutinate (positive reaction). Bacteria that are not E. coli O157 will not bind to the antibody and will not agglutinate (negative reaction).