MICROTITER ASSAY FOR DETECTING CAMPYLOBACTER SPP. AND HELICOBACTER-PYLORI WITH SURFACE GANGLIOSIDES WHICH BIND CHOLERA-TOXIN

Campylobacter jejuni with Gm1 ganglioside in the core of its lipopolys accharide has been associated with Guillain-Barre syndrome, Since this epitope may be of considerable pathophysiologic importance and since this ganglioside binds cholera toxin, a rapid screening assay to detec t bacteria that bind cholera toxin as an indication of Gm1 on their su rfaces was developed, In the assay, bacterial lawns mere grown on agar plates, harvested with phosphate-buffered saline, boiled, and incubat ed with a standard concentration of cholera B subunit, Preparations fr om strains with Gm1 were observed to inhibit the binding of cholera B subunit to Gm1 in a microtiter enzyme-linked immunosorbent assay. By u sing this assay with two groups of strains, 37 positive strains were d etected among the 197 tested. Species with positive isolates included C. jejuni, Campylobacter coli, and Helicobacter pylori. The assay is c apable of testing large numbers of isolates and should prove useful in future clinical and epidemiological studies of bacteria with this epi tope.