You and your oral flora
You and your oral microflora
A module in seven parts…
Overall learning objectives
-why are we doing this?
At the end of this module, you will be able to do the following:
• describe (some of) the microbes that live in and on the human body.
• explain the roles that microbes play in both human and health and disease, in particular the role that microbes play in immunity
• differentiate between DNA replication as it occurs within a cell and as it occurs inside of a test tube.
• navigate sources of information about microorganisms and be able to discriminate between accurate and inaccurate sources.
Learning objectives for today…
• You will be able to describe (some of) the microbes that lie in and on the human body
• Just to become comfortable working and thinking about microbes
Find a background image of bacteria adhering to a surface for this slide; good source: Science Photo Library or the ASM Microbe Library
What Are Microbes?
Types of microbes
• Find a good Electron micrograph image of each category here…
– Could also use this opportunity to get student responses for examples of each
• Prokaryotes
– Bacteria
– Archaea
• Eukaryotes
– Fungi
– Protists
– Green Algae
• Viruses
There are LOTS of microorganisms
• Insert fun cartoon
• Number of galaxies: ~ 350 billion of bacteria here
• Stars in the Milky Way: 200-400 billion
(e.g. search for
• US National Debt: 15.9 trillion (as of
8/2012)
“The fantastic
• Cells in the human body: 50-75 trillion world of
Microbiology”)
• Number of visible stars: 10 22
• Number of Microorganisms: 10 31
• 99% of microorganisms are uncharacterized!
Yes, microbes cause disease…
• Insert pie chart of
Infectious Disease
Deaths
Worldwide…good sources include CDC or
WHO, but others also useful
– http://www.who.int/mediacentre/fac tsheets/fs310/en/
– http://www.childinfo.org/mortality_u nderfive.php
• Second leading cause of death worldwide
• Dental plaque is the most widespread
• Tuberculosis affects 1/3 of world
• A child dies of malaria every minute!
– (some estimate 1 every
30 seconds)
…but most microbes are BENEFICIAL!
Help their hosts
– Insert image of intestines here
Maintain ecosystems
– Insert lovely landscape
Alter climate
– Insert storm image here
• Aid digestion
• Make vitamins
• Detoxify chemicals
• Develop the immune system
• Fight off invaders
• Cycle nutrients
• Cycle metals
• Decompose
• Fix O
2
, CO
2 and
N
2
• Food source
• Bioremediation
• Seed clouds
• Nucleate ice crystals
• Produce O
2
• Sequester CO
2
