The mechanism of the interaction of Serratia marcescens pili and human urinary mucin
Kohno, K.
Nihon Saikingaku Zasshi. Japanese Journal of Bacteriology 39(2): 85-102
1984
ISSN/ISBN: 0021-4930 PMID: 6146729 Document Number: 239992
The mechanism of the agglutination of S. marcescens pili by mucin was examined with a piliated clinical isolate of S. marcescens (US5) and partially purified human urinary mucin. Urinary mucin was purified by centrifugation and washing with PO43-buffered saline. Partially purified mucin showed a single peptide band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and, morphologically, a homogeneous mass of fine fibrous molecules in EM. A single fiber of the mucin molecule was .apprx. 14 nm in diameter and consistent of filaments in a double helix. Each filament made a turn every 28 nm. By heating at 55.degree. C for 30 min or treating with proteinase and hyaluronidase, the mucin lost its agglutinability. Agglutination was inhibited by addition of D-mannose or some of its derivatives to the reaction mixture. Evidently, the interaction of pili with mucin was mediated by the mannose residue in the mucin molecule, probably located at the bridding structure between the axial fiber and helical fiber. Piliated strains eliciting mannose-resistant hemagglutination were not agglutinated in urine. Type 1 pili of Escherichia coli eliciting mannose-sensitive agglutination also showed no agglutination in human urine. Evidently, some factor other than mannose-specific lectin activity of pili participates in the agglutination reaction. The size of pili seems to be an important factor for the agglutination. Pili with diameters larger than the pitch size of the mucin helix molecule may not be agglutinated by mucin.