Fig. 4.

Lethality in the ELA. Test groups of 15 embryos were inoculated with 10 to 30 bacteria of PS1, PS2, V1, and A4. Additional test groups included uninoculated and PBS-inoculated embryos. The experiment was done four times. The percentage of dead embryos at day 3 postinoculation was determined for each test group and calculated over all 60 embryos. Negative controls are shown as white bars, E. coli O157:H7 strains as black bars, and avian E. coli control strains as gray bars. Capital letters within the bars indicate the grouping that resulted from the Duncan's multiple-range test, which was done for embryos only if they were inoculated with bacterial strains.