Objective: To develop a mouse model of acute bacterial rhinosinusitis.
Design: Study mice (C57BL6/J) were inoculated intranasally with Streptococcus 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. The sinuses were prepared for histological investigation.
Setting: Animal care facility at a tertiary, academic institution.
Method: The histological sections of the sinuses were examined in a blinded manner for the percentage of sinus cavity occupied by neutrophil clusters, and for the number of neutrophils per square millimeter of sinus mucosa.
Results: Infected mice killed at 5 days had significantly more sinus area occupied by neutrophil clusters, significantly more neutrophils within the mucosa, and significantly more S pneumoniae growth in the intranasal cultures compared with controls (15/15 vs 0/6; P<.01). The amount of inflammation had decreased at 2 weeks.
Conclusion: Streptococcus pneumoniae induces acute bacterial rhinosinusitis in C57BL6/4 mice as measured by culture and influx of neutrophils, and can be used as a model of acute bacterial rhinosinusitis.