Bacteria from the Yersinia genus

You really don’t want to come into close contact with Yersinia bacteria, since many of them can make us very sick. For example, Yersinia pestis usually lives in fleas on rodent animals. But when it enters into a human body, it can give that person the plague disease since it turns off the health protection.

For this, Yersinia pestis has a very special weapon, that only becomes active at body temperature. It looks like a long needle that can directly poke into immune cells. The bacterium then sends proteins into the immune cell to deactivate it, so it cannot attack the bacterium anymore. Like this, the bacterium shuts off many players of the immune system to get comfortable within the body and make that person sick.