Fig. 2.

Evaluation of in vivo blood reservation. a In vivo blood reservation of bacteria. EcN or CMCB (1 × 10⁷ CFUs) were injected through the tail vein and blood was withdrawn intraorbitally at the indicated time points, diluted to 10⁻² and spread onto LB agar plates. Plates were incubated at 37 °C for 24 h prior to enumeration. b–d Bacterial engulfment by primary peritoneal macrophages. Macrophages were co-cultured with EcN or CMCB at 37 °C with 5% CO₂ for 1 h. b The percentage of macrophages containing bacteria and c the mean fluorescent intensity of the engulfed bacteria was measured by flow cytometric analysis. Error bars represent the standard deviation (n = 3). Significance was assessed using Student’s t-test, giving p-values, *p < 0.05, **p < 0.01, ***p < 0.005. d LSCM images of macrophages after co-incubated with EcN or CMCB expressing GFP at 37 °C with 5% CO₂ for 1 h. Scale bar, 10 μm