IL1B and infection: Infection with strains harboring the S203P + G231N, E232T, N235D + N291D + A515V + S528G resulted in elevated PPAD activity, which correlated with clinical indicators of disease severity, induced COX-2 (~6-fold) and <i>IL-1b</i> (~7-fold) expression in osteoblasts and led to 94% reduction in OPG.