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


“The fantastic

• Cells in the human body: 50-75 trillion world of


• 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


Worldwide…good sources include CDC or

WHO, but others also useful

– tsheets/fs310/en/

– 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


, CO

2 and



• Food source

• Bioremediation

• Seed clouds

• Nucleate ice crystals

• Produce O


• Sequester CO


To the module!