Leptospira is a genus of bacteria in the family Leptospiraceae which are aerobic (uses oxygen), able to move by themselves (are motile), and shaped like coils. There are free-living members which live in soil, freshwater, and saltwater, as well as parasitic pathogens of humans and other animals which most notably cause leptospirosis (a disease which chiefly afflicts a number of livestock and other domestic animals but can also affect humans).