Protein patterns, serotyping and plasmid DNA profiles in the epidemiologic fingerprinting of Pseudomonas aeruginosa.

The epidemiological typing schemes based on serotyping, antibiotic susceptibility pattern, plasmid DNA profile, and protein patterns determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were evaluated for their usefulness in typing clinical isolates of Pseudomonas aeruginosa. The serotypability was lower (45%) than reported in the literature (85-95%). The most commonly found serotypes were O:1 (19%), O:11 (25%), O:6 (35%). The electrophoretic analysis of plasmid DNAs showed plasmids (molecular weight = 1 to greater than 40 megadaltons). Two plasmids of Mr 2 and 38 megadaltons were found in various serotypes. The restriction enzyme analysis of plasmid DNA showed identical DNA fragment patterns among distinct serotypes. The SDS-PAGE protein banding patterns of whole-cell proteins showed homogeneity among the strains. However, analysis of the soluble protein patterns of the strains showed sufficiently distinct protein profiles that can be used to differentiate between various strains. The results of this study demonstrate that the electrophoretic patterns of soluble proteins, in combination with plasmid DNA profile or serotyping, can be of value in the epidemiologic fingerprinting of clinical isolates of Pseudomonas aeruginosa.