A MOUSE MODEL OF ACUTE BACTERIAL RHINOSINUSITIS

Objective: To develop a mouse model of acute bacterial rhinosinusitis. Design: Study mice (C57BL6/J) were inoculated intranasally with Strep tococcus pneumoniae, ATCC 49619 suspended in trypticase soy broth, and controls were inoculated with trypticase soy broth alone. After 2, 5, or 14 days, intranasal cultures were obtained and mice were killed. T he sinuses were prepared for histological investigation. Setting: Anim al care facility at a tertiary, academic institution. Method: The hist ological sections of the sinuses were examined in a blinded manner for the percentage of sinus cavity occupied by neutrophil clusters, and f or the number of neutrophils per square millimeter of sinus mucosa. Re sults: Infected mice killed at 5 days had significantly more sinus are a occupied by neutrophil clusters, significantly more neutrophils with in the mucosa, and significantly more S pneumoniae growth in the intra nasal cultures compared with controls (15/15 vs 0/6; P<.01). The amoun t of inflammation had decreased at 2 weeks. Conclusion: Streptococcus pneumoniae induces acute bacterial rhinosinusitis in C57BL6/J mice as measured by culture and influx of neutrophils, and can be used as a mo del of acute bacterial rhinosinusitis.