Leptospira
Leptospira (from Ancient Greek λεπτός (leptós) 'fine, thin, narrow, etc.' and Latin spira 'coil') is a genus of spirochaete bacteria, including a small number of pathogenic and saprophytic species. Leptospira was first observed in 1907 in kidney tissue slices of a leptospirosis victim who was described as having died of "yellow fever".