Fig. 7. Bacterial load in organs of mice infected with Streptococcus suis type 2 wild-type (WT) and its isogenic Δstp1 mutant. As the lower limit of detection was 100 colony-forming unit (CFU), we did not suggest a null result when no single colony was present in a 10 µL spot of the organ homogenates; in such a case, we assigned an arbitrary value of 50 CFU to that sample.