Pseudomonas aeruginosa causes chronic lung infections in people with cystic fibrosis
(CF) and acute opportunistic infections in people without CF. Forty two P. aeruginosa
strains from a range of clinical and environmental sources were collated into a single
reference strain panel to harmonise research on this diverse opportunistic pathogen.
To facilitate further harmonized and comparable research on P. aeruginosa, we
characterised the panel strains for growth rates, motility, virulence in the Galleria
mellonella infection model, pyocyanin and alginate production, mucoid phenotype,
lipopolysaccharide (LPS) pattern, biofilm formation, urease activity, antimicrobial and
phage susceptibilities. Phenotypic diversity across the P. aeruginosa panel was
apparent for all phenotypes examined agreeing with the marked variability seen in this
species. However, except for growth rate, the phenotypic diversity among strains from
CF versus non-CF sources was comparable. CF strains were less virulent in the G.
mellonella model than non-CF strains (p=0.037). Transmissible CF strains generally
lacked O antigen, produced less pyocyanin, and had low virulence in G. mellonella.
Further, in the three sets of sequential CF strains, virulence, O-antigen expression and
pyocyanin production were higher in the earlier isolate compared to the isolate
obtained later in infection. Overall, full phenotypic characterization of the defined panel
of P. aeruginosa strains increases our understanding of the virulence and
pathogenesis of P. aeruginosa and may provide a valuable resource for the testing of
novel therapies against this problematic pathogen.
- Pseudomonas aeruginosa
- Cystic Fibrosis