Motility and chemotaxis of three strains of Pseudomonas aeruginosa used for virulence studies

The motility and chemotaxis of 3 strains of P. aeruginosa were examined by electron microscopy, soft agar migration, and the capillary assay test. Strain M2, which is highly virulent in the burned mouse model, was vigorously motile and highly chemotactic. The avirulent strains tested, PA103 and WR5, were defective in motility and chemotaxis, respectively. These results suggest that considerable heterogeneity in chemotactic capacity exists among the P. aeruginosa strains that are used for virulence studies, and further, that chemotaxis should be examined as a possible virulence factor for P. aeruginosa.