Survival of infected hamsters and sequential change of general urinary conditions during Leptospira infection. (A) Survival rate of infected hamsters and Leptospira-positivity ratio of the urine culture were checked every day. Hamsters were infected with 103 leptospires and urine was collected every day from pre-infection to just before death. Chemical analysis of hamster urine was done using urinalysis paper and absorbance was also measured at 600 nm. Infected hamsters became moribund from the eighth day post infection. Leptospires were recovered from the urine from the seventh day after infection. Three independent experiments were done (n = 10) and the sum of the survival rate of the 10 hamsters are shown. (B and C) Urinary pH (B) and absorbance (C) changed after the seventh day. Hamster infection experiments were repeated three times. The sum of the turbidity and pH values were taken and the average (±SD) are shown (n = 10). *: p < 0.05, **: p < 0.01.