Table 2.

Resolution of res-tet-res sequences following growth in vitro and in vivoa

Strain or site% Tcs colonies (mean ± SE) after growth:
In vitrobIn vivoc
Bvg+ phase conditionsBvg phase conditionsDay 12Day 20
NBP1217.4 ± 4.589.6 ± 5.2
NBP1477.6 ± 3.486.9 ± 4.4
Nasal cavity14 ± 6.416 ± 5.8
Trachea17 ± 4.318 ± 7.2
Lungs19 ± 5.516 ± 6.7
  • a See Fig. 5.

  • b Strains were grown on BG-blood agar with or without the addition of 5 mM nicotinic acid and 5 mM MgSO4for 72 h. Cells were then harvested and plated, and the percentage of Tcs resolvants was determined.

  • c Mice were inoculated with NBP121 grown on plates containing tetracycline. At 12 and 20 days postinoculation, the percentages of Tcs colonies recovered from the nose, trachea, and lungs were determined.