FIG 3.

Carbohydrate metabolism of E. faecalis promotes NO production in macrophages. (A) Flow cytometry analyses of the level of NO in RAW264.7 cells after infection with the E. faecalis WT, Δpmi, and ΔPTS1 strains. The dead bacteria represent the E. faecalis WT strain killed by heat. The number represents the mean fluorescence intensity (MFI) with standard deviation (SD). (B) qRT-PCR analysis of the transcription of iNOS in RAW264.7 cells. More than three independent biological replicates were performed. (C) The survival of E. faecalis strains in RAW264.7 cells after 48 h of infection. L-NMMA (300 μM) was added to inhibit the production of NO in RAW264.7 cells. The viable bacterial number at the indicated time was counted by plating. n ≥ 3; **, P < 0.01 (based on Student’s t test).