FIG. 6.

(A) C. difficile B1 bacteria were most commonly found in association with PMNs within vacuoles (arrow). (B) Higher magnification of panel A. (C) When images of the vacuoles were enlarged (area indicated by open arrows in panels A and B), filamentous structures between 200 and 400 nm long were discerned (arrowheads). These structures appeared to pin back (solid arrows in panel B and solid arrow in panel C) the contents released from fusing lysosomes (open arrows in panels B and C), suggesting a possible mechanism for the cell to avoid direct contact with the digestive elements. (D) Immunogold labeling confirmed that the organisms inside the vacuole were C. difficile.