Ultrastructural effects of Clostridium difficile toxin B on smooth muscle cells and fibroblasts.
The mechanism by which Clostridium difficile toxin B causes cells in culture to round was investigated. Cultured human lung fibroblasts and rabbit aortic smooth muscle cells were treated with partially purified or purified toxin B and monitored by light and transmission electron microscopy (TEM). Both preparations caused progressive cell rounding which correlated with disorganization of actin-containing myofilament bundles. Thin myofilaments became fragmented and finally disappeared (after 24 h) and dense bodies became more prominent, while all other organelles appeared unaffected.
D000818:Animals; D001011:Aorta / Q000648:ultrastructure; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000633:toxicity*; D002460:Cell Line; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects / Q000648:ultrastructure; D006801:Humans; D008168:Lung / Q000648:ultrastructure*; D008854:Microscopy, Electron; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000648:ultrastructure*; D011817:Rabbits
D001426:Bacterial Proteins; D001427:Bacterial Toxins; C031815:toxB protein, Clostridium difficile