This scanning electron micrograph (SEM) depicts a number of Leptospira sp. bacteria atop a 0.1. µm polycarbonate filter.
Leptospira interrogans causes leptospirosis, a usually mild febrile illness that may result in liver or kidney failure. Leptospira is a flexible, spiral-shaped, Gram-negative spirochete with internal flagella. Leptospira interrogans has many serovars based on cell surface antigens. Leptospira enters the host through mucosa and broken skin, resulting in bacteremia. The spirochetes multiply in organs, most commonly the central nervous system, kidneys, and liver. They are cleared by the immune response from the blood and most tissues but persist and multiply for some time in the kidney tubules. Infective bacteria are shed in the urine. The mechanism of tissue damage is not known. Leptospirosis is a worldwide zoonosis affecting many wild and domestic animals. Humans acquire the infection by contact with the urine of infected animals. Human-to-human transmission is extremely rare.
Credit: NCBI / CDC