TY - JOUR UR - https://doi.org/10.7717/peerj.521 DO - 10.7717/peerj.521 TI - Feeding behaviour of Caenorhabditis elegans is an indicator of Pseudomonas aeruginosa PAO1 virulence AU - Lewenza,Shawn AU - Charron-Mazenod,Laetitia AU - Giroux,Lauriane AU - Zamponi,Alexandra D. A2 - Wiles,Siouxsie DA - 2014/08/12 PY - 2014 KW - Caenorhabditis elegans KW - Pseudomonas aeruginosa KW - Type III secretion KW - Nematode feeding behaviour KW - High throughput virulence model KW - Food preferences AB - Caenorhabditis elegans is commonly used as an infection model for pathogenesis studies in Pseudomonas aeruginosa. The standard virulence assays rely on the slow and fast killing or paralysis of nematodes but here we developed a behaviour assay to monitor the preferred bacterial food sources of C. elegans. We monitored the food preferences of nematodes fed the wild type PAO1 and mutants in the type III secretion (T3S) system, which is a conserved mechanism to inject secreted effectors into the host cell cytosol. A ΔexsEΔpscD mutant defective for type III secretion served as a preferred food source, while an ΔexsE mutant that overexpresses the T3S effectors was avoided. Both food sources were ingested and observed in the gastrointestinal tract. Using the slow killing assay, we showed that the ΔexsEΔpscD had reduced virulence and thus confirmed that preferred food sources are less virulent than the wild type. Next we developed a high throughput feeding behaviour assay with 48 possible food colonies in order to screen a transposon mutant library and identify potential virulence genes. C. elegans identified and consumed preferred food colonies from a grid of 48 choices. The mutants identified as preferred food sources included known virulence genes, as well as novel genes not identified in previous C. elegans infection studies. Slow killing assays were performed and confirmed that several preferred food sources also showed reduced virulence. We propose that C. elegans feeding behaviour can be used as a sensitive indicator of virulence for P. aeruginosa PAO1. VL - 2 SP - e521 T2 - PeerJ JO - PeerJ J2 - PeerJ SN - 2167-8359 ER -