Fig. 1

Intracellular survival and cytotoxicity of Bp and Bt in RAW264.7 cell. a Intracellular bacteria loads of Bp and Bt were measured at different time (4 h, 8 h, 12 h, 20 h, 24 h, MOI = 10) by gently rupture with 1% Triton X-100. b MNGC formation was observed after Bp or Bt infection to RAW264.7 cell at different time (4 h, 8 h, 12 h, 20 h, 24 h, MOI = 10), and MNGC% was calculated (MNGC% = (the number of nuclear of MNGC)/(the number of nuclear of all cells) × 100%). c Flow cytometry (FCM) was applied to evaluate cell apoptosis at different time post infection (8 h, 12 h, 24 h, MOI = 10) and early apoptosis cells were counted by gating. d mRNA level of TNF-α in RAW264.7 cell was measured by qRT-PCR at different time post infection with actin as a reference gene (8 h, 12 h, 24 h, MOI = 10). e Early apoptosis cells were counted at 12 h post infection with different dose of Bp or Bt (MOI = 1, 10, 100, 10000). f TNF-α mRNA levels were measured at 12 h post infection with different dose of Bp or Bt (MOI = 1, 10, 100, 10000). *P value < 0.05, **P value < 0.01