TABLE 1.

Neuropathogenicity in CD155tg mice

ConstructLD50Spinal cord titer
PFU or FFUaNo. of virionsbPFU or FFU/gcNo. of virions/gd
PV(M) wt3.2 × 102 PFU3.7 × 1041.0 × 109 PFU1.15 × 1011
PVAB755-15152.6 × 102 PFU7.3 × 1053.5 × 107 PFU9.8 × 1010
PVAB2470-29544.6 × 101 FFU4.8 × 1063.4 × 106 FFU3.57 × 1011
  • a LD50 expressed as the number of infectious units, as determined by plaque or infectious focus assay, required to result in 50% lethality after intracerebral inoculation.

  • b LD50 expressed as the number of virus particles, as determined by OD260 measurement, required to result in 50% lethality after intracerebral inoculation.

  • c Virus recovered from the spinal cord of infected mice at the time of death or paralysis; expressed in PFU or FFU/g of tissue, as determined by plaque or infectious focus assay.

  • d Virus recovered from the spinal cord of infected mice at the time of death or paralysis, expressed in particles/g of tissue, derived by multiplying values in the third column by the particle/PFU ratio characteristic for each virus (Fig. 3D).