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Helicobacter pylori and the Bacterial Theory of Ulcers


Debra A. Meuler
Biology Department
Cardinal Stritch University


This case is an account of the events that led Drs. Robin Warren and Barry Marshall to the bacterial theory of ulcers. The two physicians refused to accept the standard explanations for what they had observed and instead developed an alternative hypothesis, saving countless patients from unnecessary pain and suffering. Along the way they transformed the way the medical community viewed peptic ulcer disease. The case shows the importance of curiosity, serendipity, and tenacity in scientific inquiry; how science is built upon the work of others; how assumptions can cloud people's views, leaving them closed to new ideas; and how scientific "truth" can and does change when faced with new data and new interpretations. It is appropriate for use in any course at the high school or undergraduate level that teaches students about the scientific method and/or the sociology, nature, and history of science.

  • Trace the development of a major idea in biology/medicine.
  • Learn about the cultures in which the people profiled in this case story lived and worked.
  • Illustrate the scientific method using a real life example.
  • Provide insight into how a discipline's base assumptions can affect scientific progress.
  • Provide an opportunity for students to analyze authentic data.
  • Show how scientists identify a causal relationship between a pathogen and a particular disease.
Keywords: Helicobacter pylori; ulcer; gastritis; nature of science; sociology of science; experimental design; J. Robin Warren; Barry Marshall; Nobel Prize
Topical Area: History of science, Scientific method
Educational Level: High school, Undergraduate lower division, Undergraduate upper division
Formats: PDF
Type/Method: Analysis (Issues), Discussion
Language: English
Subject Headings: Biology (General)   Microbiology   Science (General)   Medicine (General)   Science Education  
Date Posted: 2/18/2011
Date Modified: N/A
Copyright: Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

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