Microbiology Lab Study guide- FINAL

1. What type of agar is Nutrient agar (NA)? All bacteria need carbon and nitrogen to grow. What ingredients in NA provide carbon for the bacteria – what macromolecules use carbon? What ingredients in NA provide nitrogen and what macromolecules use nitrogen?

2. What is the selective ingredient(s) in Columbia CNAwith 5% Sheep Blood Agar? Why is this ingredient “selective” and why will Streptococcus pyogenes, Streptococcus pneumonia and Streptococcus epidermidis (Enterococcus facecalis) grow on this agar but not E. coli or other enteric bacteria family members? What is the differential ingredient in Columbia CNAwith 5% Sheep Blood Agar? How is this plate used to identify Streptococcus pyogenes, Streptococcus pneumonia and Streptococcus epidermidis (Enterococcus facecalis)? What is seen when Streptococcus pyogenes, Streptococcus pneumonia and Streptococcus epidermidis (Enterococcus facecali)s are inoculated on this plate? What virulence factor can be seen by this agar? What does this virulence factor do inside the human body(how does this help the bacteria?) What ingredients in Columbia CNAwith 5% Sheep Blood Agar provide carbon for the bacteria – what macromolecules use carbon? What ingredients in Columbia CNAwith 5% Sheep Blood Agar provide nitrogen and what macromolecules use nitrogen?

3. What is the selective ingredient in MacConkey agar? Why is this ingredient “selective” and which types bacteria will grow on this agar (use the Genus and species names)? What is the differential ingredient in MacConkey agar? What is seen when Eschericia coli grows on this plate what is seen when Salmonella sp, Klebsiella pneumoniae, or Staphylococcus epidermidis are inoculated on this plate? What virulence factor can be seen with this agar? What does this virulence factor do inside the human body (how does this help the bacteria?) What ingredients MacConkey agar provide carbon for the bacteria – what macromolecules use carbon? What ingredients in MacConkey agar provide nitrogen and what macromolecules use nitrogen?

4. What is the selective ingredient in MSA agar? Why is this ingredient “selective” and which types bacteria will grow on this agar (use the Genus and species names)? What is the differential ingredient in MSA agar? How is this plate used to identify Staph aureus? What is seen when Staph aureus grows on this plate what is seen when other Staph sp grow on this plate? What virulence factor can be seen by this agar? What does this virulence factor do inside the human body (how does this help the bacteria?) What ingredients MSA provide carbon for the bacteria – what macromolecules use carbon? What ingredients in MSA provide nitrogen and what macromolecules use nitrogen?

5. How do antibiotics work to stop bacterial growth

a. What is the site of action of each of the antibiotics discussed in lab this term, including colistin, nalidixic acid, Penicillin, Penicillin/Clavulanic Acid (What does this drug do?), Rifampin, Streptomycin, Polymyxin.

b. What is the Zone of inhibition (ZOI) tell you about the bacteria’s sensitivity to an antibiotic?

c. What does it mean if the ZOI is small?

d. What does it mean if the ZOI is big?

6. Can you label the parts of the microscope?

7. How do you calculate the FOV on a scope?

8. If an organism stretches across the FOV at 1000X magnification how big is this organism in micrometers?

9. If a bacteria is 1 micrometer in diameter- What shape is it? How many of these bacteria fit across the FOV calculated at 1000X magnification?

10. Why must a slide be heat-fixed?

11. Virulence factors – how does of each of these help to bacteria when in a human host. Name an example of a microbe with this virulence factor

a. Flagella

b. Gram negative

c. Hemolysin

d. Ability of ferment mannitol

e. Ability to ferment lactose

f. Beta-lactamase

12. What information comes from a gram stain?

a. How does this technique highlight differences in gram + and gram – bacteria?

b. What does alcohol do to the gram negative bacteria?

c. Why do the gram positive bacteria stain purple?

d. Why do gram negative bacteria stain red?

13. What are the macromolecules? What are the building blocks of each macromolecules?

14. Where in the bacterial cell is each macromolecule found?

15. What is an infectious does of a bacteria?

16. What gram negative bacteria have been observed in lab?

17. What gram positive bacteria have been observed in lab?

18. Which observed have a flagella? What information comes from a mobility assay?

19. Which bacteria have a capsule?

20. Which bacteria are acid-fast?

21. If bacterial colonies are on a plate and can be counted what is the formula to determine the number of bacteria in the original sample?

22. What is the purpose of streak plating?

23. What is the difference between a negative staining technique and a positive staining technique?