Its growth curve in Luria–Bertani (LB) broth (Becton Dickinson, NJ, USA) and survival in soils with distinct textures were identical to those of the non-induced wild-type strain [19]. The E. coli O157:H7 suspension was inoculated into
the soil sample to establish an inoculation density of about 106 colony-forming units per gram soil oven-dry weight (CFU g−1). Subsequently, the organic fertilizers were added and thoroughly mixed with the inoculated soil at a ratio of 1 part of manure to 25 (wt/wt) parts of soil. The water content of soil samples was adjusted to the field capacity (soil water content at −33 kPa).