Detection and initial characterization of novel capsular polysaccharide among diverse Campylobacter jejuni strains using Alcian blue dye

We have recently demonstrated that most strains of Campylobacter jejuni pro duce capsular polysaccharide (CPS), which can be detected by immunoblotting with homologous Penner antisera on polyvinylidene difluoride membranes (A. V. Karlyshev, D. Linton, N. A. Gregson, A. J. Lastovica, and B. W. Wren, M ol. Microbiol. 35:529-541, 2000), In this report, we describe a universal a nd rapid staining procedure using Alcian blue for C. jejuni CPS, which does not rely on the availability of antisera and identifies CPS in untypeable strains. Furthermore, Alcian blue staining identified CPS in its lipid-free form directly an Tricine gels, and we demonstrate that CPS is thermostable and is accumulated in the culture supernatant in a lipid-free form. The id entification of a newly described CPS and its lipid-free form in C. jejuni should prove invaluable in studying the pathogenesis and epidemiology of th is important pathogen.