Abstract: | Cytochalasin B (CB) and cytochalasin D (CD), inhibitors of microfilament function of host cell, were examined for their effects on Staphylococcus aureus Cowan I adherence to and ingestion by several types of the hyperosmolarity-tolerant (HOT) cells obtained from primary culture of mouse kidney. Staphylococcal adherence to the HOT cells with epithelial appearance was extraordinarily enhanced by the treatment of those cells with both 5 μg/ml of CB and CD. In particular, staphylococci adhered to the periphery rather than the center of each cytochalasintreated cell. Staphylococcal ingestion by all types of the HOT cells was markedly inhibited by CD in spite of the enhanced adherence. Contrary to our expectation, inhibition by CB was incomplete, and the enhanced adherence of staphylococci to CB-treated cells resulted in the enhanced ingestion. |