Table 1.

Virulence of S. suis library and strains in germfree pigs

Strain No. of pigs Dose of S. suis(CFU) Mortalitya (%) Mean no. of days until death Morbidityb (%)Clinical index of the group Fever indexeLeukocyte indexfNo. of pigs in which S. suis was isolated from:
Specificc symptomsNonspecificd symptoms CNS SerosaeJoints
S735(pCOM-L) 4 107 100 4100 69 91 25NAg 3 2 3
4 108 75 7 100 50 69 2017 2 1 2
S735(pCOM-V10) 5106 100 1 100 100 100 54 45 5 5
S735(pCOM1) 4 106 2512 25 2 11 6 80 1 1 2
S735(pCOM-V10) 5 106 100 1100 100 100 60 NA5 5 5
S735(pCOM-V735) 5 106 2015 100 40 26 17 52 1 1 1
S735(pCOM1) 5 106 20 16 60 119 11 20 1 0 0
24(pCOM-V10) 5106 100 2 100 50 66 42 293 3 5
24(pCOM-V735) 4 106 2515 100 40 30 17 18 1 0 0
24(pCOM1) 5 106 20 15 20 214 6 21 1 0 0
  • a Percentage of pigs that died due to infection or had to be killed for animal welfare reasons.

  • b Percentage of pigs with specific symptoms.

  • c Percentage of observations for the experimental group in which specific symptoms (ataxia, lameness of at least one joint, and/or stillness) were observed.

  • d Percentage of observations for the experimental group in which nonspecific symptoms (loss of appetite and/or depression) were observed.

  • e Percentage of observations for the experimental group of a body temperature of >40°C.

  • f Percentage of blood samples for the experimental group in which the concentration of granulocytes was >1010/liter.

  • g NA, not applicable.