Intracellular killing of Mtb isolates 97-1200 or 97-1505 and cell death of infected alveolar macrophages. Alveolar macrophages were infected in vitro for 24 h with Mtb isolates 97-1200 or 97-1505 at MOI 5. (A) Bacterial killing was assessed by resazurin metabolisation and expressed as a percentage of phagocytised bacteria. (B) Cell viability assessed by resazurin metabolisation. Maximum viability (100%) is based on uninfected cells. (C) ELISA assay of apoptosis and necrosis 24 h post-infection of alveolar macrophages in vitro. Camptothecin 5 μg/mL (CAMP) was used as apoptosis-positive control and hypertonic buffer as necrosis-positive control. #P < 0.0001 for uninfected cells vs. infected cells (97-1505 or 97-1200); ***P < 0.0001; **P < 0.001 (one-way ANOVA). Data are representative of three (A, B) and two (C) independent experiments (error bars, s.e.m.).
Assis et al. BMC Microbiology 2014 14:128 doi:10.1186/1471-2180-14-128