jejuni by oral gavage and observed daily for clinical signs. Mice were euthanized and necropsied promptly when clinical signs of disease developed or at thirty days post-infection. Blood samples were obtained by cardiac puncture after death. Observations on gross pathological changes were recorded during necropsy. Tissue snips from stomach, jejunum,

cecum, and colon were spread on agar plates selective for C. jejuni (Selleckchem Crenigacestat tryptose soya agar plates with 5% sheeps’ blood and cefaperazone, amphotericin B, and vancomycin (TSA-CVA) [40]). All of the C. jejuni growth from cecal tissue of each individual mouse was harvested from the agar surface and frozen at -80°C to be used as the inoculum for the next serial passage. To produce the inoculum for the next passage, each frozen culture was spread on a tryptose soya sheeps’ blood agar plate with no antibiotics and incubated for 24 Mocetinostat hours at 37°C under a 10:10:80 mixture of H2, CO2, and N2; this growth was used to inoculate a second plate which was incubated 12 hours as before. Growth from the second plate was suspended in broth, and purity and motility were verified by light microscopy

and Gram staining. The suspension was adjusted to an OD600 of 1.0; the growth from all plates of a single strain was pooled to produce the inoculum. Aliquots of each inoculum were suspended in tryptose soya selleck chemical broth containing 15% glycerol and stored at -80°C for further studies. In the first serial passage, mice were inadvertently shifted from the diet containing an ~12% minimum fat to a diet containing an ~6% minimum fat just prior to inoculation with C. jejuni. This error was not discovered until after the mice had been inoculated. A previous experiment with C. jejuni infected mice on the ~12% fat diet and ~6% fat diets did not reveal a statistically significant difference in survival, gross pathology, or histopathology scores. Therefore, all subsequent passages included a similar dietary shift. In an experiment conducted in parallel with the final passage, 10 mice on the ~12% fat diet and 10 mice that had experienced Rolziracetam the dietary shift were inoculated with non-adapted (unpassaged) C. jejuni

11168. That experiment did show a statistically significant difference in histopathology scores in mice on these two diets, so a third comparison of diets was done to try to resolve the issue. Nineteen mice each were kept on the ~12% fat diet, shifted onto the ~6% fat diet at least two weeks prior to the experiment, or subjected to the ~12% fat to 6% fat diet transition 3 to 5 days prior to inoculation as experienced by the mice in the serial passage experiment. Ten mice in each of the three diet groups were inoculated with non-adapted C. jejuni 11168 and nine mice on each diet regime were inoculated with tryptose soya broth as controls. Finally, we conducted a short-term experiment to determine whether there were differences in events in early infection between the original and mouse-adapted C. jejuni 11168 strains.