Figure 3. Co-culture of S. aureus TCS and transporter mutants with S. warneri or L. lactis.

The co-culture assay is described in the Materials and Methods. A 100-µl aliquot of S. warneri ISK-1 (10⁸ cells/ml) (A) or L. lactis ATCC 11454 (10⁸ cells/ml) (B) was mixed with 100 µl of S. aureus (10⁷ cells/ml for S. warneri and 10⁶ cells/ml for L. lactis). (C) Expression of the ABC transporter vraDE in the mutants when mixed with S. warneri ISK-1 or L. lactis. *p<0.05, as determined by Dunnett’s method for the percent ratio of the S. aureus population and the expression of the ABC transporters.