Characterization of the polysaccharide antigen of Klebsiella pneumoniae O:9 lipopolysaccharide

✍ Scribed by Leann L. MacLean; Chris Whitfield; Malcolm B. Perry

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 254 KB
• Volume: 239
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(93)84231-t

✦ Synopsis

The lipopolysaccharides (LPS) of Hebsielh pneumoniae have been implicated as virulence determinants. Although some 72 K-serospecific capsular antigens have been described for Klebsiella sp., it has been suggested that there exist only 8 associated unique LPS 0-polysaccharide antigens in this gram-negative bacterial species'.

In recent re-investigations of Klebsielfa LPS 0-chains2,3, originally proposed structures have required revision, and the production of multiple unique O-chain structures by a given designated KZebsielZa serotype has been demonstrated2*3. The present investigation of the KZebsieUa 0 : 9 LPS polysaccharide has shown that it is a polymer of a branched pentasaccharide unit composed of only o-galactose residues. The newly deduced structure of the O-antigen differs from the originally proposed structure4 in the mode of linkage at its branch point and, as a consequence, also in the structure of the backbone D-galactan polymer.

The 0-polysaccharide, extracted by the method of Johnson and Perry5 as described in the Experimental section, had [aIn +93" (c 1.5, H,O) and, by quantitative GLC6 and capillary GLC of the derived (RI-Zbutyl glycosides7, was shown to be composed of D-galactose (90%). Anal. Found: C, 39.77; H, 5.71; N, 0.20; and ash 0%. The 'H NMR spectrum of the native O-chain showed signals at 6 2.12 and 2.15 indicative of 0-acetyl methyl protons while its i3C NMR spectrum (Fig. 1B) also showed 0-acetyl signals at 6 21.20 and 21.18 (CH,CO) and 173.5 and 174.7 (CH,CO). The 'H NMR spectrum of the 0-deacetylated O-polysaccharide (dil NH,OH) showed inter alia four H-l signals,