Figure 1. E. faecalis elicits fast avoidance in C. elegans.

(A) Schematic of avoidance assays (top) and representative photomicrographs (bottom) of C. elegans on lawns of E. coli OP50, P. aeruginosa PA14, or E. faecalis OG1RF at 0 hr (left) and 4 hr (right) on BHI media. Individual animals are outlined in red. Scale bar, 5 mm. (B) Occupancy index of N2 animals after 4 hr of incubation on E. coli, P. aeruginosa, E. faecalis, E. faecium, or S. aureus. One-way ANOVA with subsequent comparison to E. coli as the control group was performed. Occupancy Index = (number of animals on bacterial lawn)/(total number of animals). (C) Individual animals were tracked on lawns of E. faecalis and the time that they first left the lawn after transfer was recorded. Wild-type (WT, N2 Bristol) animals showed an average first leave time of 19.20 min while tax-2(p671) animals showed an average first leave time of 61.98 min. An unpaired t-test between the groups was performed. (D) N2 animals on standard avoidance assays plates with E. faecalis were observed for 10 min during two different time windows (0–1 hr and 3–4 hr) and the number of times the animals left and entered the bacteria lawns was counted. One-way ANOVA with subsequent comparisons between all groups was performed. (E) Occupancy index of N2 animals after 24 hr incubation on P. aeruginosa PA14 lawns or E. coli OP50 lawns supplemented with isolated total RNA from E. coli (E.c. RNA), P. aeruginosa (P.a. RNA), or E. faecalis (E.f. RNA). One-way ANOVA with subsequent comparison to E. coli RNA as the control group was performed.

Figure 1—figure supplement 1. Avoidance of Gram-positive pathogens.

(A) Occupancy index time course of N2 animals on either E. faecalis, E. faecium, or S. aureus. N = 3 for each point. Points represent the mean. (B) Response index of N2 animals to dry drops of E. coli, E. faecalis, E. faecium, BHI, LB, or 0.6 mM SDS buffer. Response Index = number of responses/total number of drops.