Figure 3

Nicotine increased S. aureus autolysis rate. (A) The mid-log phase culture (OD₆₀₀ = 0.6) was collected and then resuspended in the same volume of 0.05 M Tris-HCl (pH 7.2) containing 0.05% Triton X-100, the solution was incubated at 30 °C and OD₆₀₀ was measured every 30 min. The rate of autolysis was measured as the decline in optical density. (B) Transcriptional levels of the autolysis-related genes lytN and atlA in S. aureus USA300 strain cultured in TSB and TSB supplemented with 2 mg/mL nicotine detected by qRT-PCR(n = 3). Data were represented as mean ± SD of three independent experiments. *P < 0.05 compared with untreated group.