Communicable disease spreads from affected individuals to those unaffected. Pathogens are microorganisms which can cause disease. These include bacteria, viruses and fungi. Have a look at the little things!
There are multiple ways in which pathogens cause disease. Bacteria can produce toxins, viruses take over cellular machinery such as enzymes and nutrients and destroy the cells in the process, while fungi can secrete enzymes that break down host tissue.
There are many different kinds of bacterial toxin e.g. by Staph. aureus, such as protein barrels that integrate into the plasma membrane of host cells and cause their contents to leak out through these huge pores created by the…