MATERIALS AND METHODS
Materials
Maggots used in the present study were the third instar larva of Lucilia sericata that were raised under sterile conditions. Maggots were cultured as previously described by Wang et al[17]. Escherichia coli (E. coli) strain (O157:H7) was provided by the Department of Microecology, Dalian Medical University. The bacteria were inoculated into 200 mL of broth, cultured with shaking at 37 °C for 12 h and centrifuged at 8000 rpm for 10 min. The pellet was re- suspended in broth and diluted to 108-1010 CFU/mL.