Association patterns of Pseudomonas aeruginosa clinical isolates as revealed by virulence traits, antibiotic resistance, serotype and genotype.

The aims of this study were to assess the association patterns of 96 clinical isolates of Pseudomonas aeruginosa using hierarchical cluster analysis from data obtained from the measurement of the physicochemical cell surface properties, adhesion and initial biofilm formation abilities, to investigate any correspondence with source, serotype, beta-lactam pattern, motility and M13-PCR genogroup or clonal lineage, as well as to select clinical isolates that could act as representatives of the genotypic and phenotypic diversity of this P. aeruginosa population from a Portuguese Central Hospital. The isolates were phenotypically characterized by their ability to adhere and form biofilms on polystyrene surfaces, their affinity to hexadecane and silicone, their swimming and twitching abilities, their antibiotic susceptibility patterns and their serotypes. No particular phenotypic cluster associated with the same source, serotype, beta-lactam pattern, motility and M13-PCR genogroup and clonal lineage was found. Nevertheless, five representative strains of the P. aeruginosa population from this Hospital, selected on the basis of low genetic similarity, were also found to be dispersed among the phenotypic clusters.