Pathogenic strain
The E. coli F4 strain provided by the Laboratório de
Microbiologia do Hospital Veterinário da Universidade Estadual de Santa
Cruz (UESC) was used. The strain is maintained in brain and heart
infusion broth (BHI; BD Difco™, Franklin Lakes, NJ) +
20% glycerol, in an ultra-freezer at -80 °C, and reactivated in BHI
broth, incubated at 37 °C for 24 h.