Type-specific indirect hemagglutinating antibody in patients with Pseudomonas aeruginosa Infection.

Lipopolysaccharide antigens were extracted from heated cell extracts of several serotypes of Pseudonomas aeruginosa. Indirect hemagglutination with the extracts indicated specific reactivity with sera from rabbits immunized with homologous serotypes of P. aeruginosa. Sera from healthy adults and patients infected with P. aeruginosa were studied subsequently and shown to possess antibodies against P. aeurginosa. In patients infected with P. aeruginosa type E, indirect hemagglutination antibody against type E was resistant to 2-mercaptoethanol (2-ME) and classified as immunoglobulin G. In patients infected with any other type of P. aeruginosa and in healthy adults, it was sensitive to 2-ME and classified as immunoglobulin M. The antibody in the seven patients infected with P. aeruginosa was titrated during the course of infection with lipopolysaccharide antigen prepared from the infecting strain. As a result, all patients either possessed 2-ME-resistant antibody or showed antibody rise to homotypic antigen during the infection. However, no patient showed 2-ME-resistant antibody against hetero-typic lipopolysaccharide antigens. In hospitalized patients, the incidence of anti body against type E, G, and I Pseudomonas strains was greater than that against type A. In particular, 2-ME-resistant antibody to all four serotypes was detected at a higher rate in hospitalized patients than in healthy adults.