FIG 4.

The biosynthetic pathway of staphyloxanthin was responsible for the protection of S. aureus from CAP treatment. (A) Biochemical pathway for staphyloxanthin biosynthesis in S. aureus. The colors of staphyloxanthin and its intermediates are indicated by the background colors. (B) Surface pigmentation of Newman and its derivatives in S. aureus plaques and pellets. (C) Corresponding carotenoid pigments of S. aureus Newman and its derivatives were extracted and the OD₄₆₂ values were determined. Experiments were repeated in triplicate. Statistical significances were calculated using Student’s t test. ***, P < 0.001. (D) Survival of strain Newman and its derivatives after different times of CAP treatment. The solid symbols with different colors represent S. aureus Newman and its derivatives. The experiments were repeated five times. The numbers of surviving cells in one experiment are presented.