Escherichia coli EDL933 genetic variation. Escherichia coli strain:EDL933

E. coli that express curli are more common in soil when manure is surface applied. However, it is not known if this arises from changes in curli expression by individual bacteria or by selection for individuals already expressing higher levels of curli. To test this we examined curli expression and genetic variation in pathogenic E. coli O157:H7 EDL933 as a function of manure management. Five treatments were investigated: (1) Soil only, (2) soil with surface-applied E. coli O157:H7 EDL933 Δstx1-2 (EcO157), (3) soil spiked with EcO157, (4) soil with surface-applied EcO157-spiked manure, and (5) soil with EcO157-spiked incorporated manure.