1. BACTERIA AND VIRUSES

2. What Are Bacteria? Prokaryotic Small (1-5 um) and Unicellular
No Nucleus
No Mitochondria or Chloroplast
Single Chromosome
Small (1-5 um) and Unicellular
100 trillion in the body. That’s 100,000,000,000,000 cells!
Compared to 10 trillion human cells. 10:1 ratio
Used to be grouped as Monera

3. Archaebacteria vs. Eubacteria
Differences that resulted in the two-kingdom classification structure for bacteria include:
Biochemical differences such as cell wall and plasma membrane composition
Structure and function of genetic material particularly tRNA and rRNA base sequences (archaebacteria are actually more similar to eukaryotes, and lack peptidoglycan in the cell walls)
Reactions to antibiotics

4. Eubacteria: includes most of the “common” bacteria
Heterotrophs: these use organic molecules as food sources. Some are parasites, others are saprophytes (feeding on dead organisms or wastes).
Photosynthetic autotrophs: includes cyanobacteria. These are often found in long chains of cells.
Chemosynthetic autotrophs: these can make their own food, but they don’t undergo photosynthesis. Instead, they break down sulfur and nitrogen containing inorganic compounds.

5. Archaebacteria: thrive in extreme conditions
Methane producers: these thrive in oxygen-free environments (such as the digestive tracts of cows, marshes, and lake sediments). These are important in sewage disposal plants where they assist with the breakdown of sewage.
Salt-loving bacteria: these live in bodies of water with high levels of salts. Ex: Great Salt Lake, Dead Sea.
Heat and acid-loving bacteria: these thrive in hot, acidic waters such as sulfur springs and hot ocean vents (temps can be above the boiling point).

6. Basic structure of bacteria
They can also have other structures such as flagella (long, whip-like projections that can be used for movement) and pili (extensions of the plasma membrane). The DNA is circular and often separate pieces exist called plasmids.

7. Shapes of Bacteria Bacilli (rod-shaped)
Ex. Bacillus anthracis (Anthrax)
Spore forming
Inhalation of these spores into lungs
Treatment for Anthrax
Antibiotics like penicillin if used soon after exposure

8. Shapes of Bacteria Cocci (spherical shaped) Streptococcus aureus Cures
Strep throat
Usually found in clusters
Cures
Antibiotics (stops replication of cells)

9. Shapes of Bacteria Spirilla (Spiral shaped) Vibrio cholerae (Cholera)
Spread through contaminated water, food
Shellfish & plankton
Other filter feeders
Symptoms: Severe diarrhea, vomiting and dehydration.
Treatment: rehydration salts, and antibiotics

10. Reproduction Binary fission Conjugation
Similar to what process in humans?
Why is it different?
Can happen every 20 minutes (E. coli)
Why don’t bacteria take over the world?
Conjugation
Exchange genetic material (antibiotic res.)

11. Where do Bacteria Live? In You!! Skin
Mouth--over 500 different types of bacteria!!
S. mutans
Plaque formation and cause of cavities
Favorable environment

12. Bacteria in Your Mouth

13. Where do Bacteria Live? In You!! Intestinal Tract E. coli
Most abundant in lower GI tract

14. Where do Bacteria Live? Inanimate objects Water fountain Door handles
Keyboards
Silverware
Lockers
Dirty gym socks

15. Where do Bacteria Live? Water Coliform Bacteria What are Coliforms?
Total Coliforms
Fecal Coliforms
What are Coliforms?
Indicators for pathonogenic bacterium
Where are they found?
In rivers, lakes, swimming pools(?), drinking water(?)

16. Sources of Coliform Bacteria
Sewage (fecal coliforms)
Warm blooded mammals’ fecal material
Livestock
Cows
CAFOs
Pollution
Industry
Agricultural

17. Beneficial Bacteria Used in making foods Cheese
(Penicillin Roqueforti = blue cheese)
Wine & Beer, sauerkraut, yogurt
Oil spills
Intestinal – antagonistic and mutualistic
Wastewater treatment plants

18. viruses

19. Bacteriophages Viruses that infect BACTERIA
Bacteriophages are used to insert DNA into another organism
Bacteriophages will be shown in the animation describing the two different replication cycles of all viruses
The LYTIC cycle is an active virus which KILLS the cell
The LYSOGENIC virus is integrated into the host DNA and HIDES inside the cell

20. Lytic Virus
Lytic Bacteriophage

21. 5 Steps in the Lytic Cycle
Attachment
Entry
Replication
Assembly of new viruses
LYSIS: cell breaks open and releases new viruses into the organism or environment

22. Lysogenic Virus
Prophage infection

23. 8 steps of the Lysogenic Cycle
Attachment
Entry
Integration into the host cell’s DNA (prophage or provirus)
Replication of cells (including virus DNA)
Trigger
Replication of Virus
Assembly
Lysis

24. Common Viruses Flu Virus HIV: Retrovirus Herpes Simplex I
Chicken pox virus (shingles)
West Nile Virus: most people infected never know they have it!
Flu Virus

25. Vaccines: the war against the virus
Prevention by injecting WEAKENED or “KILLED” virus particles to cause your immune system to recognize the virus quickly
When in contact with the real virus, your IMMUNE SYSTEM should recognize the virus and come to the rescue