Aliquots (25-100 μM final concentrations, as indicated) of CPAIP, an octameric AgrD sequence-derived peptide with a cyclic thiolactone ring (shown in panel A), were added to a TGY tube freshly inoculated with the BMJV10 agrB mutant. After those cultures were grown for 5 h, the culture supernatants were processed for CPB Western blotting (panel B). A 25 mM final concentration of a negative control peptide with a non-AgrD-derived sequence was similarly added to the agrB mutant and then processed as for the CPAIP-treated cultures. For comparison, CPB production by CN3685 and BMJV10 in the absence of peptide is also shown. The Figure shows representative results that were reproducible over three repetitions.