Ail is required for efficient biofilm-independent killing of C. elegans. Groups of 40 C. elegans N2 young adults were exposed to Y. pestis KIM8-E (parent), KIM8-E Δy2446, KIM8-E Δy2034, KIM8-E Δy1324 (Δail), Δy1324 (Δail)/pAil, KIM8-E Δ4, KIM8-E Δ4/pAil, and Δy1682. Animal survival was plotted using the PRISM computer program.