1 / 6

Germ Theory

Germ Theory. Koch’s Postulates. If a microorganism is the causative agent of an infectious disease, it must be: found in abundance in all organisms suffering from the disease, but should not be found in healthy animals * isolated from a diseased organism and grown in pure  culture .

keely-logan
Download Presentation

Germ Theory

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Germ Theory

  2. Koch’s Postulates • If a microorganism is the causative agent of an infectious disease, it must be: • found in abundance in all organisms suffering from the disease, but should not be found in healthy animals* • isolated from a diseased organism and grown in pure culture. • should cause disease when introduced into a healthy organism. • must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.

  3. Koch’s Postulates Continued • Basically, Robert Koch established a scientific method for establishing the cause of a disease.  • In doing so, he pioneered the field of microbiology.  • He received a Nobel Prize in 1905 for isolating bacteria that caused anthrax, tuberculosis and cholera.  * His first postulate he abandoned some time later, after he discovered some hosts had no symptoms

  4. Steps in Pathogenesis • To cause disease, a pathogen must: • Contact the host - be transmissible • Colonize the host - adhere to and grow or multiply on host surfaces • Infect the host - proliferate in host cells or tissues • Evade the host defense system - by avoiding contact that will damage it • Damage host tissues - by physical (mechanical) or chemical means

  5. Milestones in the History of Medicine

  6. Overview of Some Diseases • The Germ Theory (around 1860) • single most important contribution by the science of microbiology to the general welfare of the world's people • The theory that microorganisms may be the cause of some or all disease. • Key to developing the germ theory of disease was a refutation of the concept of spontaneous generation. • Specific aseptic techniques are employed to avoid microbial contamination • Method of prevention of spoilage of liquid foodstuffs - Pasteurization

More Related