IL6 and infection: This was performed by collecting and analyzing the culture supernatants of lung explants infected by Fth LVS, Fth LVS ΔiglC, Fth A-660 and F-W12 24 h, 48 h and 72 h post infection to determine the levels of cytokines and chemokines (e.g. IL-1β, IL-6, TNF-α, IL-8, G-CSF, MCP-1, IP-10 and VEGF).