Theodor Escherich

German physician Theodor Escherich (1857–1911) was working as a pediatrician in his native Bavaria when he discovered the bacterium E. coli. In addition to identifying a central cause of much child mortality during his time, he focused his career on improving child care, particularly infant hygiene and nutrition.

The first pediatrician to specialize in the study of infectious diseases, Theodor Escherich identified the colon bacillus now known as Escherichia coli or E. coli. During his distinguished career, he held department chairmanships at notable institutions throughout Western Europe, including at the prestigious and influential St. Anna's Children's Hospital in Vienna, Austria.

Theodor Escherich

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Spent Childhood in Bavaria and Austria

Escherich was born November 29, 1857, in the Bavarian city of Ansbach. His father, Ferdinand Escherich, was trained in medicine and worked as a medical statistician, and his mother, Maria Sophie Frederike von Stromer, came from a respected military family. Maria died when Escherich was five, and at age ten he moved with his father to Würzburg, where, for Ferdinand, a secure government job and a new wife awaited.

Escherich joined the medical staff of the Julius Hospital in Würzburg in 1888, as first assistant to internist Karl Christian Adolf Jakob Gerhardt (1833–1902). The hospital was founded in 1576 by the bishop of Würzburg and extended its local ministry to orphans and epileptics. Under the leadership of several influential physicians, by the late 1800s, the Julius Hospital was a modern facility known for its innovative surgical methods, concern for hygiene, and its well-equipped operating theatre.

Gerhardt was a pioneering pediatrician, his focus being pathology, the study of the pathology, or path, of diseases. While working in the hospital's clinic under Gerhardt, Escherich also became interested in pediatrics. Gerhardt was by then halfway through writing his important multi-volume textbook Handbuch der Kinderkrankheiten, which focused on the diseases of childhood, and as second and later first assistant, it is likely that Escherich was involved in this project. He also gained an interest in bacteriology while serving as a scientific assistant during Gerhardt's trip to Naples, Italy, to battle a cholera epidemic in 1884. Meanwhile, with Gerhardt as his doctoral advisor, he earned his Ph.D. in medicine in the fall of 1882.

Focused Career on Treating Diseases of Childhood

From late 1882 through 1883, Escherich lived in Vienna, where he studied under Hermann Widerhofer (1832–1901). A professor at the University of Vienna, Widerhofer was also personal physician to the children of Austria's royal family, and in 1885 would assume directorship of the university's department of pediatric diseases. He was also director of the St.-Anna-Kinderhospital (St. Anna's Children's Hospital), and Escherich performed bacteriological research work there. This experience provided great opportunities for the young doctor: the third-oldest pediatric hospital in Europe, St. Anna's Hospital was 50 years old at the time, and many of its patients were children living in poverty.

By the late summer of 1884, Escherich had moved to the University of Munich to perform more research in its department of pediatrics. In October, the Bavarian government sent him to Naples, Italy, which had been hit by the cholera pandemic of 1863–75, which would kill approximately 600,000 people worldwide. He also traveled to Paris, France, to attend lectures at the city's Salpeêtrière Hospital by famous French neurologist and psychologist Jean-Martin Charcot.

Made Groundbreaking Discovery in Field of Bacteriology

In 1885 Escherich took a position as a clinical assistant in Munich, Germany, working at the “Reisingerianum,” a clinic founded in 1843 by German physician Franz Reisinger and affiliated with the University of Munich. Between 1886 and 1890, he worked at the Von Haunersche Kinderklinik, a pediatric hospital, as first assistant to clinic director Heinrich von Ranke. Also in 1886, the University of Munich awarded Escherich the title of Privatdozent, signifying his qualification to lecture as an independent professor on the university level.

It was now, at the University of Munich, that Escherich began to investigate the role of bacteria in children's illhealth. He drew on the wealth of knowledge among the school's teaching staff, as well as its state-of-the-art bacteriological laboratory and other facilities. After culturing several strains of bacteria and performing intensive laboratory testing and retesting, he presented his work to his peers in 1886 as Die Darmbakterien des Säuglings und ihre Beziehungen zur Physiologie der Verdauung (“The Enterobacteria of Infants and Their Relation to Digestion Physiology”). Most significant in this work was Escherich's discovery of a bacterium he identified as “bacterium coli commune,” now known as E. coli. This bacteria was present in the intestinal flora of all the children studied, both healthy children and those experiencing diarrheal symptoms.

The human microbiome contains many microorganisms, bacteria being the most numerous. Escherich's work provided the first scientific evidence that these microorganisms are a natural and necessary part of the digestive system; researchers would now discover microorganisms in other systems within the human body: oral, urinary, nasal, digestive, upper respiratory, and others. In 2007, the U.S. National Institutes of Health began the Human Microbiome Project, a five-year process of synthesizing the knowledge gathered from around the world and discovering the specific role of each microorganism in sustaining human health and also contributing to disease.

Pursued Career in Academics and Hospital Director

Based on his discovery of E. coli, as well as his dedication to furthering the health of children, in 1890, Escherich became professor extraordinary of pediatrics and director of St Anna's Children's Hospital at the University of Graz, advancing to professor ordinary four years later. When Widerhofer died in 1902, his responsibilities expanded and he was appointed full professor of pediatrics at the University of Vienna. The following year, he founded the Säuglingsschutz (“Infant Defense Society”), which campaigned to improve children's health by encouraging women to breast-feed their infants. His concern over the high infant mortality rate in Vienna also inspired him to advocate for a facility dedicated to prenatal and infant care. In 1904 his vision of a Kinderklinik was realized at St. Anna's Hospital, and this pediatric clinic became a model for the rest of Europe.


Oberbauer, Barbara A., Theodor Escherich: Leben und Werk, Futuramamed-Verlag, 1992.


Clinical Infectious Diseases, October 15, 2007, Stanford T. Schulman and others, “Theodor Escherich: The First Pediatric Infectious Diseases Physician?,“pp. 1025–1029.

Nature Reviews Microbiology, December 2007, Jörg Hacker and Gabriele Blum-Oehler, “In Appreciation of Theodor Escherich.”□

(MLA 8th Edition)