Microbio Week 1

What is the simple definition of a microbe?

A microbe is a living organism that usually requires a microscope to be seen.

What is the simple definition of a microbe?  Describe 3 examples of microbes that contradict this definition (1-2 sentences for each).

 

Some molds , some molds are multicellular and can grow large enough to be seen without a microscope. This contradicts the idea that all microbes are microscopic.

Algae, Certain algae are considered microbes, but some species are multicellular and visible to the naked eye. This goes against the definition that microbes must require a microscope to be seen.

1. Viruses: Viruses are often grouped with microbes, but they are not living organisms and lack cellular structure. This contradicts the definition of a microbe as a living organism.
   

List Koch's postulates in order.  In 2-3 sentences, explain why these may not always hold true (include one specific example). (1)

1. The microorganism must be present in all cases of the disease and absent from healthy individuals.

Why Koch’s postulates do not always hold true:

Why Koch’s postulates do not always hold true:
Koch’s postulates, developed by Robert Koch, do not always apply because some microbes cannot be grown in pure culture and some cause disease only under certain conditions. For example, Mycobacterium leprae, which causes leprosy, cannot be grown in laboratory culture, so it violates the second postulate even though it clearly causes disease.

List Koch's postulates in order.  In 2-3 sentences, explain why these may not always hold true (include one specific example). (2)

The microorganism must then be re-isolated from the newly diseased host and shown to be the same as the original organism.

List Koch's postulates in order.  In 2-3 sentences, explain why these may not always hold true (include one specific example). (3)

The cultured microorganism should cause the same disease when introduced into a healthy host.

List Koch's postulates in order.  In 2-3 sentences, explain why these may not always hold true (include one specific example). (4)

The microorganism must then be re-isolated from the newly diseased host and shown to be the same as the original organism.

Why Koch’s postulates do not always hold true:

Koch’s postulates, developed by Robert Koch, do not always apply because some microbes cannot be grown in pure culture and some cause disease only under certain conditions. For example, Mycobacterium leprae, which causes leprosy, cannot be grown in laboratory culture, so it violates the second postulate even though it clearly causes disease.