Evaluation of Clostridium difficile Infection with PET/CT Imaging in a Mouse Model

Purpose Existing clinical or microbiological scores are not sensitive enough to obtain prompt identification of patients at risk of complicated Clostridium difficile infection (CDI). Our aim was to use a CDI animal model to evaluate 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography ([F-18]FDG-PET) as a marker of severe course of infection. Procedures CDI was induced with cefoperazone for 10 days followed by clindamycin 1 day before C. difficile inoculation. Mice were divided into wild type (n = 6), antibiotic without infection (AC n = 4), h001-infected (n = 5, ribotype 001), and h027-infected (n = 5, ribotype 027). Two days after inoculation, [F-18]FDG-PET was acquired. Weight, general animal condition, and survival were monitored daily for 9 days. Results h001 group showed symptoms for 4 days with 0 % mortality and a similar colon uptake than control animals (h001 0.52 +/- 0.20, WT 0.42 +/- 0.07, and AC 0.36 +/- 0.06). The h027 group showed symptoms up to 7 days, with 66.7 % of mortality 4 days after infection, and significantly higher colon uptake (0.93 +/- 0.38, p < 0.05). Clinical score was associated to colon and cecum uptake (rho = 0.78, p = 0.0001) (rho = 0.73, p = 0.0003). Conclusion High toxin producer ribotype 027 induced more severe CDI infections, correlating with higher colon and cecum [F-18]FDG uptake. Colon uptake may purportedly serve as early predictor of CDI severity.