Surface Antigens of Gonococci: Correlation with Virulence and Serum Resistance

Abstract

Encapsulated and non-encapsulated variants of one strain of gonococcus were compared for their capacity to produce infection in chambers implanted subcutaneously in mice, for their reactions with specific antibody and for their precipitation with wheat germ agglutinin. Only the encapsulated variant could infect implanted chambers. Specific rabbit antiserum raised against the non-encapsulated variant killed both variants. Saline extracts and lipopolysaccharide preparations of the encapsulated variant differed from those of the non-encapsulated one in their reactions with wheat germ agglutinin and antibody in diffusion and electrophoresis tests. Preparations from infective encapsulated gonococci reacted with wheat germ agglutinin while those from the non-encapsulated variant did not. Immunodiffusion tests showed that lipopolysaccharides from both variants share a common antigenic determinant, but saline extracts and lipopolysaccharides from encapsulated gonococci possess an additional determinant. The significance of these findings is discussed.

A surface polysaccharide forms when gonococci are converted to serum resistance by cytidine 5′-monophospho-N-acetyl neuraminic acid

“…Tlus wdl require experiments with gold-labelled monoclonal antibody rinsed agmnst the stalyated LPS and demons,ration that the carbohydrate can be hydrolysed by neuraminidase treatment. Any connections of the surface polysacchande with the 'capsule' said to be present occasionally on gonococci [15] or with the somewhat strmlar appearance of gonococci in urethral exudates [16] are also matters for future research.…”

Partitioning of gonococcal LPS into phenol and water: Different LPS composition of in vivo and in vitro selected variants

“…The vivo and vitro variants of N. gonorrhoeae have been described [7], and were grown on Gclv medium [8].…”

“…The aim of this study was to investigate whether gonococcal LPS partitions into the phenol phase as well as into the aqueous fraction. Two variants of N. gonorrhoeae were used that have been described in earlier work [7,8]. One was selected by growth in subcutaneous chambers (vivo variant) and the other by repeated subculture on artificial medium (vitro variant).…”