Comparison of the virulence of Streptococcus pneumoniae in ICR mouse stocks of three different origins / 한국실험동물학회지

ABSTRACT

Streptococcus pneumoniae causes many people to suffer from pneumonia, septicemia, and other diseases worldwide. To identify the difference in susceptibility of and treatment efficacy against S. pneumoniae in three ICR mouse stocks (Korl ICR, AICR, and BICR) with different origins, mice were infected with 2 × 106, 2×107, and 2×108 CFU of S. pneumoniae D39 intratracheally. The survival of mice was observed until three weeks after the infection. The three stocks of mice showed no significant survival rate difference at 2 × 106 and 2 × 107 CFU. However, the lung and spleen weight in the AICR stock was significantly different from that in the other two stocks, whereas the liver weight in BICR stock was significantly lower than that in the other two stocks. Interestingly, no significant CFU difference in the organs was observed between the ICR stocks. The level of interferon gamma inducible protein 10 in KorlICR was significantly lower than that in the other two stocks. The level of granulocyte colony stimulating factor in BICR was significantly lower than in the other two stocks. However, tumor-necrosis factor-alpha and interleukin-6 levels showed no significant difference between the ICR stocks. In the vancomycin efficacy test after the S. pneumoniae infection, both the single-dose and double-dose vancomycin-treated groups showed a significantly better survival rate than the control group. There was no significant survival difference between the three stocks. These data showed that KorlICR, AICR, and BICR have no susceptibility difference to the S. pneumoniae D39 serotype 2.