IL1B and infection: IL-1β was detected 6 and 24 h after infection; after 6 h no significant differences were observed in any of the mycobacteria, but after 24 h the levels of this cytokine were significantly higher in the presence of fast-growing mycobacteria even though monolayer was compromised (80% integrity at 24 h for M. abscessus infections and 60% for M. fortuitum).