pathogenicity islands

Pathogenicity islands are specific segments of genetic material found in some bacteria that contain genes enabling them to cause disease. These DNA sections often originate from other bacteria and are integrated into the bacterial genome, acting as genetic "boxes" that carry the tools the bacteria need to infect hosts, evade the immune system, or produce toxins. Their presence enhances a bacteria’s ability to cause illness, and they are often transferable between bacteria, contributing to the spread of virulence traits within microbial populations.