SEROLOGIC TESTS FOR PSEUDOMONAS-AERUGINOS A - CONTRIBUTION TO THE DIFFERENTIATION OF COLONIZATION AND INFECTION IN CYSTIC-FIBROSIS PATIENTS

Serologic test for Pseudomonas aeruginosa have been found useful for d ifferentiating colonization from infection, especially in chronic dise ase. A Western blot method was compared with the ELISA used routinely. The Western blot detected serum IgGs against P. aeruginosa outer memb rane proteins, whereas the ELISA reacted with IgGs against soluble P. aeruginosa antigens. Among the 103 sera from 58 cystic fibrosis patien ts studied, all those with ELISA reactivity were positive by Western b lot. The antibody response was detected earlier by Western blot than b y ELISA, suggesting that the former technique may be useful for the ea rly diagnosis of infection.