Vaccine strain detection in fecal pellets following oral immunization.

BALB/c mice (n = 5) were orally immunized with UK-1(ΔaroA), 14028S(ΔaroA) or BSG (mock). Fecal pellets were collected on days 0, 1, 2, 3, 7, and 10 post immunization for enumeration of bacterial shedding post vaccination. 14028S(ΔaroA) titers in the fecal pellets declined significantly by day 7 and continued to decline at day 10. Mice vaccinated with UK-1(ΔaroA) maintained significantly higher bacterial titers (**P ≤ 0.01) by day 10 post immunization (last time-point analyzed) when compared to 14028S(ΔaroA)-vaccinated mice.