Question

one bacterial pathogen can cause symptoms of gastroenteritis in 2 hours after ingestion of contaminated food and another pathogen requires 3 days to cause disease. how do the pathogenic mechanisms of these bacteria differ that explains the difference in incubation time.

Answer 1

Differences in incubation time for establishing the same diseased condition between different bacteria is due to the following reasons

1. Nature of the target cell - If the target cell is accessible readily like that of epithelial cells in the gastrointestinal tract it is easier for the bacterium to establish an infection. On the other hand, if it spends time in finding its target cell inside the host body it will prolong its incubation time in the host.
2. Mechanisms the bacterium uses to evade the immune system of the host - The bacteria which has a best mechanism to evade the host immune system can able to increase in numbers within a short range of time which reduces its incubation time inside the host.
3. Toxicity of the compounds produced by the bacterium - if the toxin produced by one of the bacteria is less toxic then it takes more time to establish the same effect as produced by the highly toxic one produced from different bacteria.