English: Infection occurs over many steps first starting with the exposure to the pathogen. The body’s skin and mucous membranes do a good job of protecting us from these kind of invaders, however when there is a break in the skin for example we become more susceptible to infection. Once exposed the pathogen travels through the mucous membrane and attaches to epithelial cells. This will ultimately give the pathogen a chance to invade further into the skin and grow in numbers or colonize that area. Once there is a high enough number of pathogens that have proliferated, the microbes use quorum sensing to determine when there is enough of them to spread further to other tissues. The pathogens then release toxins that subsequently cause tissue damage and disease.