Given that acute T. gondii induced ileitis is highly dependent on Toll-like Receptor (TLR)-4 mediated signaling of lipopolysaccharide derived from Gram-negative intestinal commensals [11, 15], one could speculate that additional infection with a Gram-negative bacterium such as P. aeruginosa might further exacerbate the induced inflammatory process. Here, TLR4 is linked to Crohn ileitis.