Development of antibodies to OEP, exotoxin A and exoenzymes of Pseudomonas aeruginosa in man

Antibody titers to OEP, exotoxin A and exoenzymes (protease and elastase) in normal sera of 256 specimens of cord blood, children and adults were measured by passive hemagglutination test. Serum antibody to exotoxin A was detected in cord blood samples. The level of mean antibody titers dropped during the first year of age, then rose and reached a plateau at the age of 2 to 5 years and dropped thereafter. Mean antibody titers to OEP by age groups were similar to those of exotoxin A. Antibodies to exoenzymes were not detectable initially, but the level rose during the second year of age and reached a plateau during childhood. Positive antibody titers (1:20) to exotoxin A and OEP were found in all sera belonging to some age groups between 11 to 30 years. The rate of acquisition of antibodies to exoenzymes was low. As for the antibodies to exotoxin A, the disappearance of detectable antibody by treatment with 2-mercaptoethanol was observed during the age of 1 to 4 years. Initial pseudomonas colonization may be common and asymptomatic in infants and young children.