SRI and infection: Other virulence genes such as those encoding the infection-related factors CHIPS (chemotaxis-inhibiting protein of S. aureus, chs), staphylokinase (sak), and a complement inhibitor SCIN family protein (scn) were downregulated in 24-h biofilms of UAS391 (−2.36-, −1.66-, and −2.21-fold, respectively) and HEMRSA-15 (−3.33-, −2.92-, and −3.20-fold, respectively) compared to planktonic bacteria (Table 2).