Reduction of S. aureus exoprotein-induced cytotoxicity of HNECs by treatment with sub-inhibitory clindamycin or azithromycin. Cell viability relative to negative control (5% tryptic soy broth in cell culture medium) of HNECs treated for 24 h with untreated S. aureus (ATCC 51650, CI1 and CI2) exoproteins (no antibiotic, grey bars) or ½, ¼ or ⅛ MIC clindamycin (blue bars) or azithromycin (green bars) treated exoproteins. Positive control = 10% Triton X-100; Antibiotic control = ½ MIC clindamycin (dark blue) or azithromycin (dark green) in medium. n = 3; * p < 0.05, ** p < 0.01, one-way ANOVA, followed by LSD post hoc comparison).