Western blot analysis of PilC1. Lane 1, wild-type strain 2C43; lane 2, NM98-3; lane 3, cell-associated CFU of NM98-3 obtained after 1 h of infection; lane 4, cell-associated CFU of NM98-3 obtained after 3 h of infection; lane 5, cell-associated CFU of NM98-3 obtained after 8 h of infection; lane 6, 2C43 crgA:Sp. The antibody used to detect PilC proteins is 18P4 (17). Each well was loaded with similar amounts of protein.