Structures of the O‐antigens of Proteus bacilli belonging to OX group (serogroups O1–O3) used in Weil‐Felix test

Abstract

Structures of the O‐specific polysaccharide chains of lipopolysaccharides from Proteus group OX strains (serogroups O1–O3) used as antigens in Weil‐Felix test for diagnosis of rickettsiosis, were established. From them, the acid‐labile polysaccharide of Proteus vulgaris OX19 (O1) is built up of the following branched pentasaccharide repeating units connected via a phosphate group: where QuiNAc stands for 2‐acetamido‐2,6‐dideoxyglucose (N‐acetylquinovosamine). The basis of serospecificity of the Proteus group OX antigens and their cross‐reactivity with human anti‐rickettsial antibodies is discussed.

Structural and serological studies on a new acidic O‐specific polysaccharide of Proteus vulgaris O32

“…This may enhance the formation of struvite and carbonate apatite stones in urinary tract under alkaline conditions in the presence of ammonia, one of the products of urea decomposition caused by Proteus bacteria [11]. Recently, the importance of an acidic polysaccharide rich in galacturonic acid and galactosamine was demonstrated for migration of P. mirabilis swarm cells by reduction of surface friction [12].A few structures of P. vulgaris O-antigens have been elucidated, some of them having been found neutral [7,13] and the others acidic [7Ϫ9]. Now, we report the structure of a new acidic O-specific polysaccharide of P. vulgaris O32 containing D-galacturonic acid.…”

Human complement activation by smooth and rough Proteus mirabilis lipopolysaccharides

“…The bacteria were cultivated under aerobic conditions in nutrient broth. The complete structures of the lipid A portion, core oligosaccharide, and O-polysaccharide of the S1959, R110, and R45 LPSs were presented previously (Amano et al 1996;Ró¿alski et al 1997;Vinogradov et al 2000;Vinogradov et al 1994;Zió³kowski et al 1997).…”

“…The Proteus LPSs of R form were extracted by the phenol-chloroform-petroleum ether method (Galanos et al 1969). The LPSs were purified by DNase and RNase (Sigma Chemical Co. St. Louis, MO, USA) treatment and ultracentrifugation, as described (Amano et al 1996;Zió³kowski et al 1997). All LPSs were essentially free of nucleic acids and contained less than 2% proteins.…”

“…In the present study, one smooth P. mirabilis S1959 and its two polysaccharide-truncated LPSs isolated from an R mutant strain were used to study C3 conversion. The P. mirabilis S1959 strain was classified to the O3 serogroup and its O-polysaccharide chain is built up of pentasaccharide repeating units with amidically linked lysine residues (Amano et al 1996;Zió³kowski et al 1997). The polymer of the pentasaccharide repeating units of the O3-antigen is attached to a core oligosaccharide characterized by the presence of D-galacturonic acid residues in both the terminal and inter-chain positions (Vinogradov et al 2000).…”

“…The P. mirabilis R110 strain produces Ra-type LPS with a complete core oligosaccharide, but lacks the O-antigen (Vinogradov et al 2000). The P. mirabilis R45 strain contains a truncated core oligosaccharide (Re-type) LPS (Amano et al 1996;Ró¿alski et al 1997;Vinogradov et al 2000;Vinogradov et al 1994;Zió³kowski et al 1997). We tried to correlate C3 fragmentation with complement--mediated bacteriolysis and the role of the core and O-polysaccharide parts of the P. mirabilis LPSs in these reactions.…”