Table 3.

Quantitative recovery of H. pylori NSP335 and NSP355a

Colonizing strain (phenotype)WkLog10 CFU geometric mean titer of H. pylori in:No. colonized (n = 5)No. gastritis positive (n= 5)c
Gastric mucus from wash step:Gastric tissueb
NSP335 (I)26.2ND5.5NDd 5.3NDND5.15.050
NSP355 (II)25.8ND5.1ND4.9NDND5.15.450
  • a Bacteria were recovered from gastric mucus and epithelial cell washings at 2, 4, and 8 weeks after challenge of 10-week-old NS:Hr/ICR hairless mice with concentrated H. pylori cells. The challenge doses of H. pyloriused were 4.0 × 108 and 1.0 × 109CFU for NSP335 and 2.6 × 109 and 3.0 × 109 CFU for NSP355. The corresponding frequency of colonization and positive histopathological findings are indicated for each examination conducted at weeks 2, 4, and 8 postchallenge. Gastric tissues from all control nonchallenged mice were negative forH. pylori CFU at the second, fourth, and eighth weeks of observation (n = 5 for each necropsy time).

  • b CFU per 100 mg of homogenate.

  • c By histopathology.

  • d ND, not determined.