Phase Variation in Helicobacter pylori Lipopolysaccharide

摘要: Helicobacter pylori NCTC 11637 lipopolysaccharide (LPS) expresses the human blood group antigen Lewis x (Lex) in a polymeric form. Lex is β-d-galactose-(1-4)-[α-l-fucose-(1-3)]-β-d-acetylglucosamine. Schematically LPS structure (Lex)n-core-lipid A. In this report, we show that expression not stable trait but displays high frequency (0.2 to 0.5%) of phase variation, resulting presence several variants one bacterial cell population. One type variation implied loss α1,3-linked fucose, expressed nonsubstituted polylactosamines (also called i antigen), i.e., minus fucose; LPS: (lactosamine)n-core-lipid The switch was reversible. A second arose by main chain which resulted monomeric Ley; (Ley)-core-lipid third acquisition α1,2-linked fucose hence plus (Ley)(Lex)n-core-lipid and switched back parental phenotype [(Lex)n-core-lipid A] lower frequencies. Part can be ascribed altered levels glycosyltransferase as assessed assaying activities galactosyl-, fucosyl-, N-acetylglucosaminyltransferases. Clearly increases heterogeneity H. pylori, process may involved generating very closely related yet genetically slightly different strains have been isolated from patient.