Washed and re-suspended killed FA, equivalent to 108 CFU live FA per well, added either 24 h prior to CtE infection or immediately after CtE infection, and maintained throughout experiments, had no notable effect on CtE development/infectivity (not shown), in line with our previous gentamycin-exposure results, supporting that Ng viability is required for the observed Ng anti-chlamydial effects. This evidence concerns the gene NRGN and infection.