When two bacterial strains are orally ingested, bacterium A has an ID50 of 10,000 and bacterium B has an ID50 of 10. However, when the bacteria are injected into a mouse model of infection, bacterium...

When two bacterial strains are orally ingested, bacterium A has an ID50 of 10,000 and bacterium B has an ID50 of 10. However, when the bacteria are injected into a mouse model of infection, bacterium A (LD50 + 10) is more virulent than bacterium B (LD50 + 10,000). Explain how these results might be possible.