What are some mechanisms by which pathogenic bacteria cause diseases? Why is this knowledge important?

Pathogenic bacteria have characteristics called as virulence factors that help them to parasite their host. Some bacteria have fimbriae, cilium-like structures that attach the bacterial cell to the host tissue. There are bacteria specialized in intracellular parasitism. Other bacteria secrete toxins, molecules that cause disease; in some cases, the bacterial population growth causes food contamination by toxins. Generally, bacterial disease is caused by bacterial population growth with invasion and destruction of tissues or by bacterial toxins that contaminate the organism.

Bacterial Cell Review - Image Diversity: bacterial virulence factors