TABLE 3.

Antilisterial resistance to an intranasal challenge with L. monocytogenes in intranasally immunized mice

Immunization routeaImmune dose (CFU/mouse)Log bacteria (CFU/organ)b in:
LiverSpleenLung
NoneNone2.86 ± 0.383.81 ± 0.463.92 ± 0.58
Intravenously5 × 1042.00 ± 0.24c1.39 ± 0.31d<1.0
Intranasally5 × 1042.57 ± 0.552.41 ± 0.47d3.16 ± 0.73
Intranasally1 × 1062.10 ± 0.12c<1.02.23 ± 0.47d
  • a Mice were immunized with different doses of L. monocytogenes. They were reinfected intranasally with 106 CFU of L. monocytogenes.

  • b The number of L. monocytogenes in the organs was determined 3 days after secondary infection. Each results represents the mean ± standard deviation for a group of four mice.

  • c Significantly difference from the value for nonimmunized group (P < 0.05).

  • d Significantly difference from the value for nonimmunized group (P < 0.01).