The influence of lipopolysaccharide (LPS) O-polysaccharide chain production on the colonisation ability of Helicobacter pylori in four mouse models (NMRI, C57BL/6, CBA/Ca, and BALB/cA mice) was studied. H. pylori strains that produced smooth-form LPS (S-LPS) detectable in silver-stained electrophoretic gels colonised mice. In contrast, a laboratory-passaged strain G50 and the culture collection strain CCUG 17874 did not colonise mice; the former strain produced low amounts of O-chains only detectable in immunoblotting but not in silver-stained gels, whereas the latter produced rough-form LPS (R-LPS) without O-chains. Furthermore, a galE isogenic mutant, which produced R-LPS, did not colonise mice. However, after repeated broth culture, strains G50 and CCUG 17874 produced S-LPS detectable in silver-stained gels and were capable of colonising mice. Consistent with the production of O-chains, all colonising strains produced Lewis (Le) antigens, Le(x) and/or Le(y). Except for low expression of Le(y) by non-colonising G50, reflecting low production of O-chains, all other non-colonising strains and the galE mutant lacked expression of Le antigens consistent with their production of R-LPS. Lectin typing of strains supported these findings, and also showed that lectin types did not differ before and after colonisation. The low level of O-chain production and Le antigen expression by the non-colonising G50 may not be sufficient to aid colonisation. Examination of protein profiles of H. pylori strains before inoculation showed that protein expression was not significantly different between colonising and non-colonising strains. These results show that S-LPS production with O-chain expression is required by H. pylori for colonisation in a number of mouse models and that care should be taken with inoculating H. pylori strains that loss of O-chains does not occur during subculturing.

Mild acid hydrolysis of the smooth-type lipopolysaccharide (LPS) of Pectinatus ,frisingensis afforded no polysaccharide but monomeric 6-deoxy-~-altrose (L-6dAlt) which was identified by anion-exchange chromatography in borate buffer, GLC/MS, 'H-NMR spectroscopy, and optical rotation. LPS was degraded with alkali under reductive conditions to give a completely 0-deacylated polysaccharide, which was studied by methylation analysis, 'H-NMR and IT-NMR spectroscopy, including sequential, selective spin-decoupling, two-dimensional correlation spectroscopy (COSY), COSY with relayed coherence transfer, two-dimensional heteronuclear "C,'H-COSY, one-dimensional NOE and two-dimensional rotating-frame NOE spectroscopy. It was found that the 0-specific polysaccharide chain of l? frisingensis LPS is a homopolymer of 6-deoxy-~-altrofuranose built up of tetrasaccharide-repeating units having the following structure:Similarly, mild acid degradation of smooth-type LPS of Pectinatus cerevisiiphilus resulted in depolymerisation of the polysaccharide chain to give a disaccharide consisting of D-glUCoSe and D-fucose. Study of the disaccharide by methylation analysis and alkali-degraded LPS by one-dimensional and twodimensional 'H-NMR and "C-NMR spectroscopy showed that the 0-specific polysaccharide of I? cerevisiiphilus has the following structure : --.2)-~-~-Fucf-(l-+2)-a-~-Glcp-(l--,Keywords: Pectinatus ; lipopolysaccharide; 0-specific polysaccharide; structure; methylation.Recently, outer-membrane lipopolysaccharides (LPS) of two species of the strictly anaerobic beer spoilage bacteria of the genus Pectinatus have been isolated and chemically characterised [l]. Both species (l? cerevisiiphilus and 19 frisingensis) elaborated mainly smooth-type LPS, but small amounts of chemically distinct rough-type LPS was also extracted from the cells. Sugar analysis showed that the 0-specific polysaccharide chains of the smooth-type Pectinatus LPSs are rich in 6-deoxyhexoses [I]. We now report the structures of the 0-specific polysaccharides of P. cerevisiiphilus and 19 frisingensis. The former contains, amongst others, D-fucofuranose, whereas the latter is a homopolymer of 6-deoxy-~-altrofuranose. EXPERIMENTAL PROCEDURESChromatography. Gel-permeation chromatography was carried out on a column (40 cmX2.S cm) of Sephadex G-50 or on a column (40 cmX1.5 cm) of TSK HW-40 using 0.5 M pyridine acetate, pH 4.5, or water, respectively as eluent; monitoring was performed using a Knauer differential refractometer. Anionexchange chromatography was performed with a column (15 cmX0.6 cm) of Durrum DAX4 resin using 0.S M sodium borate, pH 9, at 55 "C and monitored using a Biotronik LC-2000 sugar analyser. GLC was performed using a Hewlett-Packard 5890 instrument equipped with a glass capillary column (25 mX0.2 mm) coated with Ultra 1 stationary phase.NMR spectroscopy. NMR spectra of D,O solutions were run with a Bruker WM-250 instrument at 60°C. Acetone was used as internal standard (~3~2 . 2 3 ppm, 6,31.45 ppm). Selective spin decoupling [2], one-dimensiona...

Mild acid hydrolysis of the smooth-type lipopolysaccharide (LPS) of Pectinatus ,frisingensis afforded no polysaccharide but monomeric 6-deoxy-~-altrose (L-6dAlt) which was identified by anion-exchange chromatography in borate buffer, GLC/MS, 'H-NMR spectroscopy, and optical rotation. LPS was degraded with alkali under reductive conditions to give a completely 0-deacylated polysaccharide, which was studied by methylation analysis, 'H-NMR and IT-NMR spectroscopy, including sequential, selective spin-decoupling, two-dimensional correlation spectroscopy (COSY), COSY with relayed coherence transfer, two-dimensional heteronuclear "C,'H-COSY, one-dimensional NOE and two-dimensional rotating-frame NOE spectroscopy. It was found that the 0-specific polysaccharide chain of l? frisingensis LPS is a homopolymer of 6-deoxy-~-altrofuranose built up of tetrasaccharide-repeating units having the following structure:Similarly, mild acid degradation of smooth-type LPS of Pectinatus cerevisiiphilus resulted in depolymerisation of the polysaccharide chain to give a disaccharide consisting of D-glUCoSe and D-fucose. Study of the disaccharide by methylation analysis and alkali-degraded LPS by one-dimensional and twodimensional 'H-NMR and "C-NMR spectroscopy showed that the 0-specific polysaccharide of I? cerevisiiphilus has the following structure : --.2)-~-~-Fucf-(l-+2)-a-~-Glcp-(l--,Keywords: Pectinatus ; lipopolysaccharide; 0-specific polysaccharide; structure; methylation.Recently, outer-membrane lipopolysaccharides (LPS) of two species of the strictly anaerobic beer spoilage bacteria of the genus Pectinatus have been isolated and chemically characterised [l]. Both species (l? cerevisiiphilus and 19 frisingensis) elaborated mainly smooth-type LPS, but small amounts of chemically distinct rough-type LPS was also extracted from the cells. Sugar analysis showed that the 0-specific polysaccharide chains of the smooth-type Pectinatus LPSs are rich in 6-deoxyhexoses [I]. We now report the structures of the 0-specific polysaccharides of P. cerevisiiphilus and 19 frisingensis. The former contains, amongst others, D-fucofuranose, whereas the latter is a homopolymer of 6-deoxy-~-altrofuranose. EXPERIMENTAL PROCEDURESChromatography. Gel-permeation chromatography was carried out on a column (40 cmX2.S cm) of Sephadex G-50 or on a column (40 cmX1.5 cm) of TSK HW-40 using 0.5 M pyridine acetate, pH 4.5, or water, respectively as eluent; monitoring was performed using a Knauer differential refractometer. Anionexchange chromatography was performed with a column (15 cmX0.6 cm) of Durrum DAX4 resin using 0.S M sodium borate, pH 9, at 55 "C and monitored using a Biotronik LC-2000 sugar analyser. GLC was performed using a Hewlett-Packard 5890 instrument equipped with a glass capillary column (25 mX0.2 mm) coated with Ultra 1 stationary phase.NMR spectroscopy. NMR spectra of D,O solutions were run with a Bruker WM-250 instrument at 60°C. Acetone was used as internal standard (~3~2 . 2 3 ppm, 6,31.45 ppm). Selective spin decoupling [2], one-dimensiona...