Fig. 2.

Summary of viable counts (log₁₀) of Hi, y axis, from cultures of fluid obtained over a period of 26 days (x axis) after inoculation of 50–100 Hi at day 0. Open circles represent quantitative cultures from individual samples of middle-ear fluid after inoculation with one of five representative Hi strains (see Fig. 1): 486, 375, 477, 285, or 162. Filled circles indicate the results of chinchillas inoculated with the isogenic siaB mutants. The lowest detectable number of organisms is 100 cfu/ml (logarithm 100 = 2). Thus, for all samples obtained from chinchillas where organisms were not detected (zero cfu), a value of log₁₀₀ was assigned, and these data points are plotted within the area labeled “Less than 100 cfu/ml.”