Flow cytometric analysis of the localization of Helicobacter pylori antigens during different growth phases

Previous studies on the localization of several different helicobacter pylo ri antigens have been contradictory. We have therefore examined by using bo th one- and two-color flow cytometry (FCM), immunofluorescence (IF), and im munoelectron microscopy (IEM). the possible surface localization of some H. pylori antigens that may be important virulence factors. Ail four methods detected the lipopolysaccharide and the N-acetyl-neuroaminyllactose-binding hemagglutinin protein (HpaA) as surface-exposed, while the urease enzyme w as not detected at all and the neutrophil activating protein only in low co ncentration on the surface of the H. pylori bacteria during culture of H. p ylori in liquid broth for 11 days. The FCM analysis was found to be quits s ensitive and specific and also extremely fast compared with IF and IEM. and therefore the preferred method for detection of surface-localized antigens of H. pylori, (C) 2001 Federation of European Microbiological Societies. P ublished by Elsevier Science B.V. All rights reserved.