Electrophoretic separation and molecular weight characterization of Pseudomonas aeruginosa H-antigen flagellins

We found that preparations of Pseudomonas aeruginosa flagellar antigens protected against P. aeruginosa challenge in a burned-mouse model. To determine the extent of similarity among known flagellar antigen types, we compared flagellins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A majority of our laboratory strains and clinical isolates, including PAO strains and their derivative mutants RM46 and PJ108, as well as virulent strains M-2 and 1244, had flagellins of 53,000 Mr. These flagellins had the same Mrs as those of type b-standard strains 170001 and 15084. The heterogeneous group of a-type H-antigen flagellins were of smaller molecular weights, ranging from 52,000 Mr for standard strain 5939 (a0, a3) to 45,000 Mr for standard strain 170018 (a0, a3, a4). Standard strains 5933 (a0, a1, a2) and 5940 (a0, a2) had intermediate Mrs of 51,000 and 47,000, respectively. Differences in Mr of 1,000 to 2,000 could be resolved by coelectrophoresis. A series of 26 unknown strains were categorized. Correlations among typing by molecular weight, cross-agglutination reactions with O-adsorbed H antisera, and previous results for H-serum typing are reported.