Which German physician discovered the bacterium that causes gonorrhea?

Which German physician discovered the bacterium that causes gonorrhea? Albert Neisser did.

In 1879, Neisser examined pus samples from patients with gonorrhea and identified distinctive paired spherical bacteria, later known as Neisseria gonorrhoeae. The organism is a Gram-negative diplococcus that commonly infects the mucous membranes of the genital tract, but it can also affect the throat, rectum, eyes, and joints.

Neisser’s observation was a major step, but proving causation took further work. Max Bockhart later linked the cultured organism more conclusively to gonorrhea, while the bacterium’s formal name, Neisseria gonorrhoeae, honors Neisser. A common mix-up is confusing discovery of the organism with development of an effective treatment: antibiotics such as penicillin came decades later, and modern strains have developed substantial resistance.

Neisser also contributed to research on leprosy and syphilis. His name therefore appears in both medical history and microbiology, not only in the name of the gonorrhea bacterium.