Comparison between bioluminescence imaging technique and CFU count for the study of oropharyngeal candidiasis in mice.

We recently described a bioluminescence in vivo imaging technique, representing a powerful tool to test the real-time progression of oropharyngeal candidiasis, hence potentially useful to evaluate the efficacy of antifungal therapies. In this study, the in vivo imaging technique was compared with CFU measurement of target organs (tongue, esophagus and stomach) for monitoring and quantifying oropharyngeal candidiasis. We have correlated these two analytical methods at different times post-infection using engineered, luminescent Candida albicans in mice rendered susceptible to oral candidiasis by cortisone-acetate. Scatter plots, Pearson correlation and Student's t test were used to compare the methods. We observed that the bioluminescence in vivo imaging technique was more reliable than CFU counts in detecting early infection of, and its extent in, the oral cavity of the mouse. This was also evident following the introduction of a variable such as treatment with fluconazole. The results described in this study could validate the bioluminescence in vivo imaging technique as a method to monitor and quantify oropharyngeal candidiasis and to assess early discovery of active compounds in vivo.