Feasibility of Helicobacter pylori identification by a slide agglutination test

Culture isolation and identification of Helicobacter pylori represents a considerable work load in clinical microbiology. The aim of this study was to test if antibody-mediated bacterial agglutination could be used for rapid identification of H. pylori. Rabbit antiserum against H. pylori strain I and against another strain, H. pylori 330, which was very weakly agglutinated (1+) by anti-H. pylori I serum, were mixed and used in a slide agglutination test. Of 107 consecutive clinical isolates tested, 101 (94%) strains showed 2+ or 3+ reaction using the antiserum mixture, whereas 6 (6%) strains could not be evaluated owing to autoagglutinability. Bacteria of a variety of other species, including Campylobacter spp., showed no agglutination with the antiserum mixture. The results support the notion that reliable identification of the majority of cultured H. pylori strains should be possible in less than 3 min by agglutination testing.