Figure 5. Effect of individual clones harboring an enterotoxin gene from ETEC JG280 on the life span of C. elegans in the absence or presence of Lactobacillus.
(A) Effect of individual enterotoxin clones on the life span of C. elegans. Worms were fed one of the following for 10 days: ♦,clone DH5α-16SRNA at 2×108 CFU/ml; ×, clone DH5α-LT at 2×108 CFU/ml; ▪, clone DH5α-STa at 2×108 CFU/ml; ▴, clone DH5α-STb at 2×108 CFU/ml; +, OP50 then ETEC JG280 at 2×108 CFU/ml. (B) and (C) Effect of isolates LB1 (L. zeae) and CL11 (L. casei)) on the life span of C. elegans infected with individual enterotoxin clones. Worms treated with ETEC JG280 isolate LB1, or CL11 only served as the controls for corresponding treatments. The concentration of all bacterial cultures used for the assays was 2×108 CFU/ml. In the treatment groups, worms were treated initially with a Lactobacillus isolate at 108 CFU/ml for 18 h and then with an individual clone or ETEC JG280 (2×108 CFU/ml) for the remaining days. All the assays were kept for 10 days. ▪, isolate LB1 or CL11 only; •, isolate LB1 or CL11 and then clone DH5α-LT; ×, isolate LB1 or CL11 and then clone DH5α-STa; ♦, isolate LB1 or CL11 and then clone DH5α-STb; ▴, isolate LB1 or CL11 and then ETEC JG280; +, OP50 and then ETEC JG280.