Figure 4.
Protective role of cTSA56 against heterologous genotype infection. Mice (n = 5/group) were immunized with the indicated antigens and challenged i.p. with 100 × LD50 of O. tsutsugamushi. Mice were immunized with antigens from the Boryong genotype and challenged with the indicated genotypes. Survival rate (A) and body weight change (B) of mice were observed for 30 d after infection. CNT, mock-immunized; *p < .05; **p < .01. (C) Bacterial loads in the spleens of mice (n = 4/group) infected with Boryong or Kato genotype were assessed by qRT-PCR using primer sets detecting the p47 gene of O. tsutsugamushi. The infected tissues were collected at 7 days after infection. Black circle, mock-immunized; red circle, TSA56-immunized; blue circle, cTSA56-immunized. Red line, mean; *p < .05; **p < .01.