NOD2 and listeriosis: Recent findings suggest that two out of the four recognized families of PRRs, NLRs and TLRs, contributing to the pathogenesis of neurodevelopmental and neurodegenerative disorders through the gut-brain axis.441 Take the enteric mouse pathogen Citrobacter rodentium as an example; it induces an IL-17 reaction via mechanisms that rely on NOD1 and NOD2. 442 Mice lacking NOD1 and NOD2 exhibit heightened susceptibility to Listeria infection upon initial exposure to LPS or E. coli.