FLAGELLIN GENE AND PROTEIN VARIATION AMONGST CLINICAL ISOLATES OF PSEUDOMONAS-AERUGINOSA

Flagellin gene sequences from 64 clinical isolates of the opportunisti c pathogen Pseudomonas aeruginosa were amplified by PCR and subjected to RFLP analysis by using seven restriction enzymes to digest the ampl ified products. Using this approach the isolates were assigned to one of 13 groups. The method was rapid, reproducible and applicable to all isolates. In contrast, serotyping failed to satisfactorily resolve 49 % of the strains tested. The vast majority of clinical isolates genera ted amplified products of 1.02 kb (type a) or 1.25 kb (type b). Electr on microscopical analysis revealed evidence for some flagellar structu ral variation between P. aeruginosa strains. This study provides furth er evidence that the flagellin gene is a widely applicable and useful genetic marker for studying genetic variation within populations of cl osely related bacteria.