In 1675 Dutch scientist Antony Von Leeuwenhoek observed bacteria and named them animalcule. In 1773, the Danish scientist Müller named the rod-shaped organisms as bacilli. In 1829, German scientist C. G. Ehrenberg was the first to name the small organisms bacteria. In 1869, the French scientist Louis Pasteur established the Germ theory of disease by extensive research on bacteria. In 1878, German physician and scientist Sadilot named bacteria as microbes. In 1952, Zinder and Linderberg discovered the bacterial transduction system. In 1968, scientist Mary included bacteria as prokaryotes. German physician Robert Koch is called the father of bacteriology.