For each mutant line, 8 female mutant mice plus 8 female wildtype control mice are infected orally with 0.2ml Citrobacter rodentium lux 109 at 6 weeks of age and are monitored over 28 days. Every 2 to 3 days faeces is collected from each mouse and the amount of bacteria in the faeces is enumerated by serial dilutions and plating onto agar plates. Every 3 to 4 days the mice may be imaged under a bioluminescence camera for 5 minutes. At day 14 post infection, 4 mutant and 4 wildtypes are schedule 1 killed. The spleen, liver, caecal patch, caecum, caecal contents and the last 6 cm of colon are extracted and the amount of bacteria in the tissue/contents is enumerated by serial dilution and plating onto agar plates. In addition, the 6 cm of colon is weighed to look for signs of gross hyperplasia, and the last 0.5 cm of most distal colon is removed and fixed for histology. At day 28 post infection the remaining mice are schedule 1 killed and the day 14 post infection procedures repeated. Mice are weighed daily throughout the infection.