Pathogenesis of plant-associated Pseudomonas aeruginosa in Caenorhabditis elegans model

Pseudomonas aeruginosa is a globally dreaded pathogen that triggers fatality in immuno-compromised individuals. The agricultural ecosystem is a massive reservoir of this bacterium, and several studies have recommended P. aeruginosa to promote plant growth. However, there were limited attempts to evaluate the health risks associated with plant-associated P. aeruginosa. The current study hypothesized that agricultural P. aeruginosa strains exhibit eukaryotic pathogenicity despite their plant-beneficial traits.

We have demonstrated that feeding with the plant-associated P. aeruginosa strains significantly affects Caenorhabditis elegans health. Out of the 18 P. aeruginosa strain tested, PPA03, PPA08, PPA10, PPA13, PPA14, PPA17, and PPA18 isolated from cucumber, tomato, eggplant, and chili exhibited higher virulence and pathogenicity. Correlation studies indicated that nearly 40% of mortality in C. elegans was triggered by the P. aeruginosa strains with high levels of pyocyanin (> 9 µg/ml) and biofilm to planktonic ratio (> 8).

This study demonstrated that plant-associated P. aeruginosa could be a potential threat to human health similar to the clinical strains. Pyocyanin could be a potential biomarker to screen the pathogenic P. aeruginosa strains in the agricultural ecosystem.