Listeria characteristics

Listeria monocytogenes
Listeria monocytogenes is a bacterium commonly found in soil, stream water, sewage, plants, and food. Each bacterium is Gram-positive and rod-shaped. Listeria are known to be the bacteria responsible for listeriosis, a rare but lethal food-borne infection that has a devastating mortality rate of 25% (Salmonella, in comparison, has a less than 1% mortality rate ). They are incredibly hardy and able to grow in temperatures ranging from 4°C (39°F), the temperature of a refrigerator, to 37°C (99°F), the body's internal temperature. Furthermore, listerosis's deadliness can be partially attributed to the infection's ability to spread to the nervous system and cause meningitis. Finally, Listeria has a particularly high occurrence rate in newborns because of its ability to infect the fetus by penetrating the endothelial layer of the placenta.