1. Classifying Bacteria Bergey’s Manual of Systematic Bacteriology
Classifies bacteria via evolutionary or genetic relationships.
Bergey’s Manual of Determinative Bacteriology
Classifies bacteria by cell wall composition, morphology, biochemical tests, differential staining, etc.

2. Prokaryotic Organisms
Prokaryotic-means pre-nucleus.
Genetic material not enclosed in a special nuclear membrane.
What are the other differences between Prokaryotic and Eukaryotic organisms.
Prokaryotic organisms are split into two Domains.
Bacteria
Archaea

3. The Prokaryotes

4. Domain Bacteria Phylum Proteobacteria
Contains most of the gram negative bacteria.
Relationships have been put together via Ribosomal RNA studies.
Split up into five classes.
Alpha, beta, gamma, delta, and epsilon

5. Alphaproteobacteria
The Alphaproteobacteria contain many bacteria that are capable of nitrogen fixation in symbiosis with plants.
What is nitrogen fixation?
Also includes several plant and human pathogens.

6. The Alphaproteobacteria
Human pathogens
Bartonella
B. hensela: Cat-scratch disease
Brucella: Brucellosis
Can survive phagocytosis, an important element of the body’s defense against bacteria.

7. The Alphaproteobacteria
Obligate intracellular parasites
Rickettsia: Arthropod-borne, spotted fevers
R. rickettsii: Rocky Mountain spotted fever

8. The Alphaproteobacteria
Plant pathogen
Agrobacterium: Insert a plasmid into plant cells, inducing a tumor
Figure 9.19

9. The Alphaproteobacteria
Nitrogen-fixing bacteria
Rhizobium
Fix nitrogen in the roots of plants
Figure 27.5, step 5

10. The Betaproteobacteria
Neisseria
Usually inhabit the mucous membranes of mammals.
N. meningitidis
N. gonorrhoeae
Figures 11.4, 11.6

11. The Gammaproteobacteria
Pseudomonas
Opportunistic
pathogens
Metabolically diverse
Polar flagella
Figure 11.7

12. The Gammaproteobacteria
Legionella
Found in streams, warm-water pipes, cooling towers
L. pneumophilia
Legionellosis or legionaire’s disease
Figure 24.15b

13. Enteric Bacteria Genera
Escherichia-Very commonly found in human intestines. Known for its ability to cause very serious food-borne disease.
Salmonella-Almost all members of this genera are potential pathogens.
Serratia-Can be found on catheters, in saline irrigation solutions, and in other supposedly sterile situations.
Proteus-very motile genera, many flagella, can cause UTI’s or wound infections.

14. The Epsilonproteobacteria
Helicobacter
Multiple flagella
Peptic ulcers
Stomach cancer
Figure 11.12

15. Cyanobacteria Oxygenic photosynthesis
Heterocysts-specialized cells that fix nitrogen.

16. Firmicutes Low G + C ratio-Guanine and cytosine bases in DNA.
Gram-positive bacteria.

17. Clostridiales Clostridium Endospore-producing Obligate anaerobes
C. tetani- tetanus,
C. Botulinum- Botulism
C. perfringens- gas gangrene,
C. difficile- serious diarrhea,
Especially when undergoing
Antibiotic therapy.
Figures 11.15, 11.16

18. Bacillales Bacillus Endospore-producing rods
B. anthracis –cause anthrax
Figure 11.17b

19. Bacillales Staphylococcus S. aureus-cause a lot of hospital infection.
MRSA- methicillin resistant S. aureus.
Figure 11.18

20. Members of this genus are probably responsible for more
Streptococcus-
Members of this genus are probably responsible for more
Diseases than any other
group of bacteria.
Pneumonia, strep throat,
cavities, scarlet fever.
Figure 11.19

21. Actinobacteria High G + C-guanine and cytosine levels in DNA.
Gram-positive

22. Important Genera Mycobacterium
M. tuberculosis
M. leprae-causes leprosy.
Propionibacterium-Some species help make swiss cheese, others cause acne.
Streptomyces-produce a a large number of antibiotics.
Figure 11.21b

23. Phylum Spirochaetes Treponema T. pallidum is the cause of syphilis.
Figure 11.24

24. Domain Archaea Hyperthermophiles Methanogens Extreme halophiles
Pyrodictium
Sulfolobus
Methanogens
Methanobacterium
Extreme halophiles
Halobacterium
Figure 11.26

25. Homework
Write a few sentences about the difference between gram positive cell walls and gram negative cell walls, and how the gram stain came about.
Also define:
Nitrogen fixation
Plasmids
Diseases
Rocky Mountain Spotted fever
Legionellosis
MRSA
Scarlet Fever
Cat-scratch disease
Brucellosis
Peptic Ulcers (Helicobacter)