Figure 3.

Attenuation of the staphylococcal skin abscess by a synthetic thiolactone-containing peptide. (A) Effect of inhibitory peptide on murine skin abscesses. Six- to eight-wk-old hairless mice were injected s.c. in the flank area on day zero with approximately 10⁸ colony-forming units of S. aureus from an exponential-phase culture grown in CY broth. The size of the resulting s.c. abscesses were measured with dividers every 24 hr; sizes were calculated by assuming that lesions were approximately elliptical and of approximately uniform depth. Four mice were injected with strain RN6390B (agr+), four with RN6911 (agr-null), three with RN6390B + 5 μg of synthetic AIPII (group II thiolactone peptide), and three with RN6390B + 10 μg of synthetic AIPII. In each case the peptide was included with the bacteria being injected. The graph shows the data plotted as average lesion size, with error bars representing the SD. The differences among the sizes of the lesions induced by RN6911 and by RN6390B plus the peptide are not significant. (B–D) Typical lesion sizes at day 5 are shown. (B) RN6390B; (C) RN6911; (D) RN6390B + 5 μg of synthetic AIPII.