Analysis of comparative virulence analysis for HV-positive and -negative K. pneumoniae. In the pneumonia model, bacterial counts in the lung (A) and blood (B) at 20 hours post-infection with the HV-negative 1084 or the HV-positive 1112 were determined in diabetic mice (filled columns) or naïve mice (striped columns). In the KLA model, 1084 (C, E) and 1112 (D, F) were orally inoculated into diabetic mice with inoculums of 105 CFU (C, D) or into naïve mice with inoculums of 108 CFU (E, F). Twenty microliters of blood was removed from the retroorbital sinus of mice at 24 h, 48 h, and 72 h post-inoculation; and the bacterial loads were determined using the plate-counting method. Each symbol represents the data obtained from a particular mouse. The bacterial load recovered from a particular mouse tissue, which was beyond the detection limit (approximately 40 CFU), is not represented. Survival of these mice was monitored daily for seven days. The survival rate of the 1112-infected (solid line) or the 1084-infected (dotted line) diabetic (G) or naïve (H) mice was determined by Kaplan-Meier analysis. Data were compiled from results obtained from three independent experiments.