The reason eggs are potentially dangerous is because the chickens must endure conditions that produce disease.

P. multocida-directed mutants have been tested for their ability to produce disease.

Yet the fact was that only 3 percent of them produced human disease; the rest were either harmless or beneficial.

Not all microorganisms produce disease, however, and many are beneficial.

So, I hope I've introduced to you the very different styles by which microbes produce disease and indicated the balance of factors involved.

Pathogenicity is the capacity of certain organisms to produce disease.

It was intended to prevent a virus that has already entered the body from producing disease.

Where and when is the gene required and how does it produce disease?

However, no specific event is sufficient by itself to produce disease.

Researchers are now using the powerful tools of molecular genetics to understand how these bacteria produce disease, and why.