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The adherence of Bordetella pertussis to human respiratory cilia is critical to the pathogenesis of whooping cough. To explore the development of agents that could interrupt adherence, the structure of the receptor on the ciliary surface was investigated. Using an in vitro adherence assay to human ciliated epithelial cells, galactose, lactose, and complex carbohydrates containing lactose eliminated adherence when preincubated with the bacteria. 10(-2) M galactose eluted adherent bacteria from cilia. B. pertussis and its two purified adhesins bound specifically to natural lactose-containing glycolipids in a TLC assay. mAbs to eukaryotic glycoconjugates with specificity for substituted galactose-glucose moieties blocked adherence when preincubated with ciliated cells. The carbohydrates that serve as receptors for B. pertussis on human cilia are galactose-glucose-containing glycolipids. Receptor analogs and anti-receptor antibodies effectively block adherence of B. pertussis to cilia and thus should be considered candidates for therapeutic intervention against disease.

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From vegetative cells of Myxococcus fulvus the lipopolysaccharide was isolated by the phenolwater procedure and its composition studied. Mannose, D-galactose, D-glucose, rhamnose, glucosamine and galactosamine were found to be the main sugar constituents. Smaller amounts of ribose, xylose, arabinose, 3-O-methyl-~-xylose and 2-keto-3-deoxyoctonate were also found. Heptose was absent. Among the fatty acids iso-branched fatty acids were predominant, i.e. 13-methyltetradecanoic acid, 3-hydroxy-13-methyltetradecanoic acid, and 3-hydroxy-15-methyl-hexadecanoic acid. In addition non-branched fatty acids were present in small amounts, like dodecanoic, tetradecanoic, hexadecanoic and octadecanoic acid as well as 3-hydroxy-tetradecanoic and 3-hydroxy-hexadecanoic acid. The 2,3-and 3,4-unsaturated fatty acids detected in hydrolysates were shown to be artifacts formed from 3-hydroxy fatty acids during hydrolysis. By gentle acidic treatment of the lipopolysaccharide lipid A was obtained containing glucosamine, fatty acids and phosphate as the main constituents. Ester-bound and amide-bound fatty acids were differentiated.Similar sugar and fatty acid compositions were found in the lipopolysaccharides of 5 fruiting and non-fruiting strains of myxobacteria. However, heptose which was absent in the other strains occurred in the lipopolysaccharide of Plexibacter Sp F x 1/2.The vegetative cells of fruiting and non-fruiting myxobacteria of the orders myxobacterales and flexibacterales are gram-negative, non-flagellated rods which exhibit as a common feature flexibility and gliding motility over the surface of solid substrates. The members of the order myxobacterales eventually will aggregate into complex fruiting structures and form myxospores [l].Because of their unique behaviour one might suspect that the myxobacteria have cell walls different from those of eubacteria. However, on electron micrographs their cell wall is indistinguishable from that of other gram-negative bacteria [2] and, furthermore, it was found that the peptidoglycan (Myxococcus xunthus) had the usual composition. I n contrast to other gram-negative bacteria the peptidoglycan does not form a closed bag, but rather consists of numerous patches [3] which might explain the flexibility of the cells. These results leads to the assumption that myxobacteria might also contain lipopolysaccharides which are typical components of the outer membrane of gram-negative bacteria. In fact, the extraction of Myxococcus fulvus Mxf2 vegetative cells with phenol-water led to the isolation of a lipopolysaccharide [4], whose main constituents were recognized as mannose, galactose, glucose, hexosamine, rhamnose, 2-keto-3-deoxyoctonate and fatty acids. I n addition 3-O-methyl-~-xy1ose was identified [5]. Furthermore, the sugar composition of a number of lipopolysaccharides, obtained from fruiting and non-fruiting myxobacteria [6] was determined showing a great similarity of chemical composition in both orders of myxobacteria.The present paper describes the detailed analysis of the su...

The fatty acids present in the total hydrolysates of several gliding bacteria (Myxococcus fulvus, Stigmatella aurantiaca, Cytophaga johnsonae, Cytophaga sp. strain samoa and Flexibacter elegans) were analyzed by combined gas-liquid chromatography and mass spectrometry. In addition to 13-methyl-tetradecanoic acid, 15-methyl-hexadecanoic acid, hexadecanoic acid, and hexadecenoic acid, 2and 3-hydroxy fatty acids comprised up to 50% of the total fatty acids. The majority was odd-numbered and iso-branched. Small amounts of even-numbered and unbranched fatty acids were also present. Whereas 2-hydroxy-15-methylhexadecanoic acid was characteristic for myxobacteria, 2-hydroxy-13-methyltetradecanoic acid, 3-hydroxy-13-methyl-tetradecanoic acid, and 3-hydroxy-15methyl-hexadecanoic acid were dominant in the Cytophaga-Flexibacter group.