Koch's postulates are criteria used to establish that:

• A. antibiotics are effective against all bacteria
• B. all microorganisms are pathogenic
• C. viruses can be cultured on nutrient agar
• D. a specific microorganism causes a particular disease

Answer: (D)

Verified step by step guidance

1. Understand that Koch's postulates are a set of criteria designed to establish a causal relationship between a specific microorganism and a particular disease.
2. Recall the four main postulates: (1) The microorganism must be found in all organisms suffering from the disease, but not in healthy organisms; (2) The microorganism must be isolated from a diseased organism and grown in pure culture; (3) The cultured microorganism should cause disease when introduced into a healthy organism; (4) The microorganism must be re-isolated from the experimentally infected host and identified as being identical to the original specific causative agent.
3. Recognize that Koch's postulates do not address antibiotic effectiveness, pathogenicity of all microorganisms, or culturing viruses on nutrient agar, so those options are incorrect.
4. Conclude that the correct interpretation of Koch's postulates is that they establish that a specific microorganism causes a particular disease.
5. Summarize that Koch's postulates are fundamental in microbiology for linking microbes to diseases, which is essential for diagnosis and treatment development.