FIG. 1.

The relationship between the formation of membrane pores in human PMNs and PVL production in USA300. Strains were grown for 18 h in CCY medium, as described in Materials and Methods. The supernatant dilutions are indicated in the key and the level of PVL in the culture medium was determined by using PVL ELISA, as indicated. The formation of membrane pores in PMNs was determined by the uptake of PI, as described elsewhere (9). The results obtained with the same blood donor, are expressed as the mean of three experiments ± the standard error of the mean. *, P < 0.05 versus CCY (analysis of variance).