The serology of Pseudomonas aeruginosa analysed by means of quantitative immunoelectrophoretic methods. II. Comparison of the antibody response in man against thirteen O groups of Ps. aeruginosa.

The occurrence of antibodies against antigens prepared from strains representing 13 O 
groups of Pseudomonas aeruginosa and against a polyvalent Ps. aeruginosa antigen 
(St-Ag) has been investigated in sera from 100 patients. By means 
of fused rocket immunoelectrophoresis with intermediate gel it was found that 
the humoral immune response against Ps. aeruginosa resulting in precipitating antibodies 
will be detected by St-Ag as well as by any other 
of the antigen samples investigated. Six of the sera contained group-specific 
antibodies which were revealed by only one of the antigen samples 
used and not by St-Ag. These six sera were further studied 
by means of various quantitative immunoelectrophoretic methods using St-Ag as well 
as antigens prepared from the infecting Ps. aeruginosa strain in the 
patient concerned. In all six sera, only one extra precipitin could 
be detected using antigens prepared from the homologous strain instead of 
St-Ag. This extra precipitin corresponded presumably to group-specific O-antigens not included 
in St-Ag. In sera from patients, these group-specific antibodies were always 
accompanied by antibodies against antigens common to all strains of Ps. 
aeruginosa. 