Major outer membrane proteins from many Campylobacter species cross-react with cholera toxin

We have previously shown that Campylobacter jejuni strains do not produce a functional cholera toxin-like toxin (CTLT) detectable in a Chinese hamster ovary cell assay. Instead, the 53-kDa major outer membrane protein (OMP) of C. jejuni, PorA, reacts with cholera toxin (CT) antibody on immunoblots. Here, we have extended this observation to other species of Campylobacter, including C. coli, C. lari, C. fetus, C. hyointestinalis, and C. upsaliensis, the common 53-kDa OMP of which reacted with CT antibody in immunoblotting assays. There were additional reactive bands for C. fetus. As with C. jejuni, this finding may lead to the erroneous conclusion that these additional species produce a functional CTLT. However, this common cross-reactive OMP can be explored as a vaccine candidate to prevent campylobacteriosis.