Robert Koch discovered the etiologic agent of?

Appeared in: BHU NO - 2015

Explanation

Robert Koch is a key figure in the history of microbiology, credited with several major discoveries.
In 1882, he successfully isolated and identified Mycobacterium tuberculosis as the bacterium responsible for causing tuberculosis.
This bacterium is often referred to as 'Koch's bacillus' in his honor.
His work provided definitive proof for the germ theory of disease, revolutionizing the understanding and treatment of infectious diseases.

Option A: The bacterium causing typhoid fever, Salmonella typhi, was first observed by Karl Joseph Eberth in 1880 and first cultured by Georg Gaffky in 1884, not by Robert Koch.
Option B: Smallpox is caused by the Variola virus. While the disease has a long history, the major breakthrough was Edward Jenner's development of the smallpox vaccine in 1796, well before Koch's time and the discovery of viruses.
Option D: The poliovirus, the causative agent of poliomyelitis, was first isolated in 1909 by two Austrian physicians, Karl Landsteiner and Erwin Popper.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Historical Discoveries in Microbiology as background academic context rather than a clinical decision trigger.
Understanding the historical basis of microbiology helps nurses appreciate the importance of infection control measures, such as isolation precautions for patients with active tuberculosis, which are direct applications of the germ theory proven by Koch.
Koch's postulates provide the logical framework that underpins modern diagnostic microbiology. When a nurse sends a patient's sample to the lab, the process of identifying the pathogen is based on these principles.
What if? If a patient presents with a fever and cough of unknown origin, the principles established by Koch guide the diagnostic process: obtain a sputum sample (isolate the organism), culture it (grow it), and identify it to confirm the cause, which directly impacts the choice of antimicrobial therapy.

How to Approach the Question

This is a factual recall question based on the history of medicine and microbiology.
Identify the key figure mentioned in the question stem: 'Robert Koch'.
Access your knowledge about the major scientific contributions of Robert Koch.
Systematically evaluate each option to see which disease's etiologic agent was discovered by him.
Recall that Koch is most famously associated with tuberculosis and cholera.
Select 'Tuberculosis' as it is one of his most significant discoveries.

Concept Tested & Keywords

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E6 Pathology-Textbook of PATHOLOGYHarsh Mohan Part 1 (1-214) p. 114-116

E6 PATHOLOGY QUICK REVIEWBased on Harsh Mohan Textbook of PATHOLOGY p. 172-174

E6 Medicine Harrison 22e Part 1 p. 1421-1423

Practise the full BHU NO - 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.