aggregative adherence mucus biofilm intimate attachment of bacteria actin Delivery of cytotoxin condensation and microvillous Delivery of LT or ST effacement enterotoxins delivery of shiga toxin ETEC EHEC EAEC elongated initial adherence via BFP intimate attachment normal cytoplasm invasion actin condensation phagosomal and microvillous rupture effacement lateral intracellular spread to movement adjacent cell DAEC EPEC EIEC