Table 1. Statistical analysis of the protection effect of lactic acid-producing bacterial isolates on C. elegans infected with ETEC JG280a.
P-valuef | |||||||
Treatmentb | Originc | Putative identityd | Survival (%) | 95% CI (± %) | DT50e (day) | L+J vs E. coli OP50 | L+J vs E+J |
E+JG280 | 0.00 | 4.67 | 3.70 | <0.0001 | |||
E. coli OP50 | 91.11 | 5.67 | >10 | <0.0001 | |||
CL10 | P | Lactobacillus acidophilus | 39.47 | 8.13 | 6.03 | <0.0001 | <0.0001 |
CL11 | P | Lactobacillus casei | 23.26 | 6.34 | 3.78 | <0.0001 | 0.046 |
CL12 | P | Lactobacillus amylovorus | 39.02 | 7.91 | 7.52 | <0.0001 | <0.0001 |
K16 | P | Pediococcus pentosaceus | 67.74 | 3.21 | >10 | 0.004 | <0.0001 |
K30 | P | Lactobacillus sp. | 35.71 | 8.26 | 6.01 | <0.0001 | <0.0001 |
K67 | P | Lactobacillus reuteri | 30.77 | 3.12 | 4.99 | <0.0001 | 0.006 |
S8 | P | Lactobacillus plantarum | 34.88 | 5.41 | 5.34 | <0.0001 | 0.001 |
S20 | P | Lactobacillus johnsonii | 21.82 | 3.63 | 5.28 | <0.0001 | 0.001 |
S33 | P | Pediococcus pentosaceus | 70.00 | 5.94 | >10 | 0.005 | <0.0001 |
S64 | C | Lactobacillus reuteri | 77.42 | 5.75 | >10 | 0.049 | <0.0001 |
S65 | P | Lactobacillus plantarum | 61.29 | 11.17 | >10 | <0.001 | <0.0001 |
S66 | P | Lactobacillus plantarum | 56.82 | 10.12 | >10 | <0.0001 | <0.0001 |
LB1 | C | Lactobacillus zeae | 78.57 | 7.28 | >10 | 0.093 | <0.0001 |
Heat-killed LB1 | 22.12 | 5.67 | >10 | <0.0001 | 0.047 |
Summary of two or more separate experiments. Survival of worms on the last day (day 10) of the assays with 95% confidence interval (CI) was estimated with the Kaplan-Meier survival analysis.
E+JG280: treatment with E. coli OP50 and then with ETEC K88 strain JG280. In the assays with LAB isolates, the nematode was firstly treated with a LAB isolate and then with ETEC JG280.
C, isolates from chickens; P, isolates from pigs.
Putative species identity was determined by BLAST analysis of sequences of 16S rRNA genes. Sequence similarities between the isolates and the 16S rDNA database sequences were 98 to 100%. Among the thirteen isolates, CL10, CL11, CL12, S64 and LB1 have been reported previously (7).
DT50, the time at which half of the worms were dead.
Comparisons of survival curves. L+J, C. elegans was treated with Lactobacillus and then JG280. L+J vs E. coli OP50, the statistical difference between the group of C. elegans treated with Lactobacillus followed by JG280 and the group of C. elegans treated with E. coli OP50 only (control group). L+J vs E+J, the statistical difference between the group of C. elegans treated with Lactobacillus followed by JG280 and the group of C. elegans treated with E. coli OP50 followed by JG280.