Soil is another common vector associated with produce. Gagliardi and Karns (2000) demonstrated
that E. coli O157:H7-inoculated manure was positive for the pathogen at different levels depending on the type of soil (sandy loam or clay loam), amount of rainfall (1e8 h and drain overnight), and soil depth (0e10 cm). The persistence of E. coli O157:H7 in soil is a potential source of contamination to strawberries via soil splashing due to rainfall, aerial irrigation or windblown dust. Gagliardi and Karns (2000) reported that soil pores can be clogged due to rain
or heavy compartment of the soil, and E. coli O157:H7 can travel below the top layer soil to the root system for more than 2 months after the initial application (Gagliardi and Karns, 2000). In our study, E. coli was recovered in the soil samples at harvest from contamination at all the stages of growth even though contamination did not occur directly into the soil, and the highest levels of E. coli at harvest came from the soil contaminated 15 weeks earlier.