GENETIC DIVERSITY OF FLAGELLINS OF PSEUDOMONAS-AERUGINOSA

Physical genome analysis of the virulence-associated fliC locus in 20 Pseudomonas aeruginosa strains by mapping and sequencing revealed grou ps of heterologous a-type (1164 bp; 1185 bp) and highly conserved b-ty pe (1467 bp) flagellin genes. Whereas only two synonymous nucleotide s ubstitutions were detected in eight b-type fliC sequences, the 12 a-ty pe sequences exhibited 57 nucleotide substitutions, of which 39 occurr ed within a variable central region. Although a-type and b-type flagel lins differ by 35% in their primary structure, they share strong homol ogy in their predicted features, implying that the polymorphic protein s fold into similar structures during polymerization of the flagella.