Role of lipopolysaccharide in wheat germ agglutinin-mediated agglutination of Neisseria meningitidis and Neisseria gonorrhoeae.

Wheat germ agglutinin, having specificity for N-acetyl glucosamine, agglutinated known nonencapsulated Neisseria meningtidis strains, but failed to agglutinate encapsulated strains of all serogroups tested Presence of a capsule, therefore, blocked wheat germ agglutinin agglutination of N. meningitidis strains. In contrast, Neisseria gonorrhoeae strains were strongly agglutinated, providing additional evidence for nonencapsulation of N. meningitidis strains. In contrast, Neisseria gonorrhoeae strains were strongly agglutinated, providing additional evidence for nonencapsulation of N. gonorrhoeae. Purified lipopolysaccharide from a single N. meningitidis and N. gonorrhoeae strains tested. Thus, in absence of capsular polysaccharide wheat germ agglutinin agglutinates Niesseria strains through interaction with lipoplysaccharide in the outer membrane. Of 34 nongroupable throat N. meningitidis isolates, 10 failed to agglutinate in wheat germ agglutinin, suggesing that at least some nongroupable. N. meningitidis strains may possess capsule-like materials.