Q.59 Which one of the following is NOT a contribution by Robert Koch?
(A) Identification of causative agent of anthrax.
(B) Discovery of causative agent of tuberculosis.
(C) Discovery of causative agent of leprosy.
(D) Identification of causative agent of cholera

Robert Koch, a pioneering microbiologist, identified key bacterial pathogens and established Koch’s postulates for proving disease causation. The correct answer to the question is (C) Discovery of causative agent of leprosy, as Koch did not identify Mycobacterium leprae.​

Correct Answer

Option (C) is not a contribution by Robert Koch. Mycobacterium leprae, the bacterium causing leprosy, was discovered by Gerhard Armauer Hansen in 1873, not Koch.​

Option Explanations

(A) Anthrax Causative Agent

Koch identified Bacillus anthracis as the cause of anthrax in 1876 through experiments with blood samples from infected animals, fulfilling early versions of his postulates.​

(B) Tuberculosis Causative Agent

In 1882, Koch discovered Mycobacterium tuberculosis, earning the 1905 Nobel Prize; he cultured it and infected animals to prove causation.​

(C) Leprosy Causative Agent

Koch did not discover the leprosy bacterium; Hansen’s 1873 identification predates Koch’s major works, and Koch focused on other diseases like cholera.​

(D) Cholera Causative Agent

Koch isolated Vibrio cholerae in 1883 during an Egyptian outbreak, observing its comma shape in stool samples despite challenges with pure cultures.​