Theodor Albrecht Edwin Klebs was a German-Swiss microbiologist. He is mainly known for his work on infectious diseases. His works paved the way for the beginning of modern bacteriology, and inspired Louis Pasteur and Robert Koch. He was the first to identify a bacterium that causes diphtheria, which was called Klebs–Loeffler bacterium. He was the father of physician Arnold Klebs.

Brigadier General George Miller Sternberg was a U.S. Army physician who is considered the first American bacteriologist, having written Manual of Bacteriology (1892). After he survived typhoid and yellow fever, Sternberg documented the cause of malaria (1881), discovered the cause of lobar pneumonia (1881), and confirmed the roles of the bacilli of tuberculosis and typhoid fever (1886).