Figure 4.

NTSp and NTHi persist together in the chinchilla middle ear. Chinchillas were inoculated via transbullar injection with a high or low dose of NTSp, alone or in combination with NTHi (see the section ‘Materials and Methods’). At four and seven days post-inoculation, animals were euthanized and bacterial loads were assessed for S. pneumoniae (A and C) and NTHi (B and D) in homogenized middle ear tissue (A and B) and middle ear fluid (C and D). The geometric mean (solid horizontal line) was calculated for each group and did not include values below the bacterial limit of detection (dashed horizontal lines). Inflammation was evaluated by otoscopic examination at one, four and six days post-inoculation (E); graph shows mean otoscopy scores, with error bars denoting the range of scores in each group. *P < 0.05; **P < 0.01.