1. Introduction to Bacteria

2. Ubiquity of Bacteria
Ubiquity [yoo-bik-wi-tee] : the state or capacity of being everywhere
The ubiquity of bacteria refers to the concept that microorganisms are EVERYWHERE
Bacteria are the most widely distributed organisms in the biosphere.
Soil, water, air
Normal flora: microorganisms that live on and in our body that do not cause harm
Only place where bacteria are not found in the body are in areas that are purposely made sterile (Remember Pasteur’s efforts to make medium stay clean?????)
Some Body fluids (pancreatic, bile, cerebrospinal, kidney filtrate)
Clean rooms
Sterilized/autoclaved equipment

3. What makes an organism a bacterium?
Bacteria are easily defined by their cellular structure and size
Lacks a defined nucleus that is surrounded by a nuclear membrane (only a little DNA; no need for over-organization)
Lack complex organelles (i.e. mitochondria)
Cell wall contains peptidoglycan
Approximately μm in diameter
by comparison, the average red blood cell is 6-8 μm

4. Handling Bacterial Cultures
Aseptic technique: keeps unwanted microorganisms out (reduces contamination)
Purpose: keep the area clean; helps keep the culture clean
Disinfecting work area
All tools used to handle bacteria need to be sterile
Loops/Needles: flamed in the incinerator to sterilize
Tubes, plates, and any other tools: autoclaved/irradiated to kill any existing bacteria
Keep all cultures covered until ready for use
Be aware of your area-if you are unsure if your tools have been compromised, then start over

5. Characterizing Microorganisms
I’m Lonely!!
Binary Fission
Colony

6. Characterizing Microorganisms
Colony morphology
Form: surface view
Elevation: height
Margin: edge
Color
Smell
Cell morphology
Size
Shape
Gram stain reaction
Acid-fast reaction

7. Be sure you can tell the morphology of each organism
Look over Slides #4-11
Be sure you can tell the morphology of each organism
Bacillus/rod, cocci, vibrio/curved, spirochete
Know the correct spelling and nomenclature of each microorganism
There are pictures of the slides on the website

8. Shapes of Bacteria Bacillus (bacilli)
short bacilli
Pseudomonas
Shapes of Bacteria
Bacillus (bacilli)
generic term to describe the morphology of any rod-shaped bacterium (one axis much different than another).
long bacilli
Bacillus
Bacillus with endospores (endospore stain)

9. Shapes of Bacteria Coccus (cocci)
any bacterium that has a spherical, ovoid, or generally round shape
cocci in chains
Streptococci
cocci in clusters
Staphylococci

10. Shapes of bacteria
Vibrio
Possessing a curved-rod shape (comma shape)

11. Shapes of bacteria Spirochete Possessing a helical/corkscrew shape
Treponema pallidum, Borrelia burgdorferi