Rapid nature of B. cereus endophthalmitis. Rapid nature of B. cereus endophthalmitis. Approximately 100 CFU of a clinical endophthalmitis isolate of B. cereus was injected intravitreally at 0 h (22). Whole eyes were harvested for histological analysis at 6, 9, and 12 h postinfection. The progression of experimental B. cereus endophthalmitis mimics that of the natural clinical course, including rapid influx of inflammatory cells into the posterior and anterior segment and dissolution of retinal architecture during the later stages of infection. At 6 h postinfection, little inflammation is observed on gross histological examination. By 9 h postinfection, extensive inflammation is seen in the posterior and anterior segment. Corneal and conjunctival edema and dissolution of retinal layers are apparent. By 12 h, the posterior and anterior segments are engorged with inflammatory cells and fibrin, and the architecture of the globe has begun to degrade. All sections were stained with hematoxylin-eosin. Michelle C. Callegan et al. Clin. Microbiol. Rev. 2002; doi:10.1128/CMR.15.1.111-124.2002