FIG. 5.

Effect of temporin-1Tb on the colonization of P. aeruginosa ATCC 15692 within the nematode gut and the animal's survival. Nematodes were infected with the GFP-expressing P. aeruginosa strain ATCC 15692 for 16 h to increase the number of intestinal bacteria, as described in Materials and Methods. (A) Fluorescence photomicrographs of a representative nematode after 90 min of treatment with 0.5 nM temporin-1Tb. A representative non-peptide-treated animal (Ut) was included for comparison. The arrows indicate the anterior intestine. (B) Survival of infected nematodes after 1 and 2 days of treatment with temporin-1Tb at 0.5 nM in an agar medium assay in comparison with untreated infected nematodes (Ut). The reported values represent the means of at least three independent experiments; the error bars indicate SD. Control animals not exposed to the pathogen and fed with E. coli OP50 exhibited 100% viability at each time point. Similar data were obtained when temporin-1Tb was replaced by Esc(1-18) and therefore are not shown.