1. Partial Materials in the Final Lab Exam (Nov
Partial Materials in the Final Lab Exam (Nov. 28/29): Labs #9-23 (All labs after the first lab exam) Please also read the review sheets I handed out on Nov. 20 in lab. I will have office hour M/Th: 9:15 a.m. - 10:15 a.m. at DH 553 or DH 543 (my lab)

2. LAB 9: Single Colony Isolation
Know how to obtain single colonies through the “Streak for Isolation” on an agar plate technique.

3. Streak Plate technique

5. Lab #9 All in NA plates Micrococcus luteus Staphylococcus aureus
Serratia marcescens
Klebsiella rosea

6. Blood agar (BA) is a differential medium.
- Some bacteria produce an enzyme that is able to lyse RBCs –
this process is hemolysis.
- By growing bacteria on blood agar we can determine if the
bacteria produce hemolysin and thus lyse the RBCs.
- Blood agar is NA to which sheep RBCs have been added.
- If hemolysin is produced by the bacteria it will be secreted
into the medium and the RBCs will be lysed
(the medium will be clear rather than red).
- So presence of clearing around the bacterial growth indicates
hemolysis.
- Growth on BA differentiates between the hemolytic and
non-hemolytic bacteria.

7. Gamma hemolysis = No hemolysis
Alpha hemolysis = Partial
Beta hemolysis = Complete

9. Lab 10: Stock and Working Slants
Why did we prepare a stock and a working stock slant for the unknown?
Why did we grow the unknown in different media and under different conditions?

10. “Working” “Stock”

11. Lab 11: Simple Staining & Bacterial Smear
Understand simple, negative, and positive staining.
Know how to prepare a bacteria smear

12. Demos: simple stains of:
Neisseria (diplococci) Pseudomonas (bacilli)

13. Lab 12: Differential Staining (Gram Stain)
Know the entire Gram Staining procedure and the function of each step.
Know the Endospore procedure (in Appendix, p. 121)

14. GRAM STAIN
E coli (Gm -)
Staph epidermidis (Gm+)

15. ENDOSPORE STAIN Bacillus megaterium See Appendix IV, p. 121
Outcome for endospore + for Micr20
Bacillus anthracis
Clostridium tetani

16. Cell Arrangements:

17. Lab 13: Selective and Differential Media
EMB: Eosin-Methylene Blue
a. Differential and selective properties.
b.Contains bile salts and the dyes eosin and methylene blue; all inhibitory to Gram-positive bacteria (e.g. Staphylococcus aureus).
c. Selects for Gram-negative bacteria (e.g. Escherichia. coli).
d.Differentiates lactose fermenting (dark color with metallic sheen) from non-lactose-fermenting (colorless) bacteria.

18. Salmonella pullorum
E. coli
Staph. epidermidis
Staph. aureus

19. Lab 13: Selective and Differential Media
TGA: Tellurite Glycine Agar
a.Selects for coagulase-positive staphylococci.
b.Differential: coagulase-positive cocci form black colonies.
c.Coagulase-negative cocci are generally inhibited. The ones that grow are gray.
d.Most Bacilli and Pseudomonas (Gm+) are inhibited.
e.Proteus sp rarely grows and form brown colonies.

20. Staph. aureus
E. coli
Staph. epidermidis
Salmonella pullorum

21. Know all the media we covered in Micro20 since lab #9: The purpose of the medium, how to read a positive and a negative result, what those results mean, and the MAJOR components of the medium.

22. Lab 14: Antibiotic Sensitivity
Antibiotics are chemicals that are produced by other bacteria/fungi
that have the ability to prevent other organisms (bacteria) from
growing or killing them.
Sensitivity X Resistance to antibiotics.
Bacteriostasis (stopping bacterial growth) X bacteriocide (killing of bacteria).
Broad spectrum antibiotics- effective against a wide range of bacteria (G+ and G-).
Narrow spectrum antibiotics - effective against a small specific group of bacteria (either G+ or G-).

23. Lab 14: Antibiotic Sensitivity; Disc Diffusion Method

24. LAB 15: Catalase, Amylase, Gelatinase (Proteinase), MRVP
MRVP, see Appendix IV, p

25. CATALASE H2O2 Negative Positive Enterococcus faecalis
Streptococcus aureus

26. Amylase: Starch Hydrolysis
BEFORE
AFTER
Flood with Iodine solution
E.coli
Bacillus subtilis
E coli - (neg.)
Bacillus subtilis + (pos.)

27. Gelatinase test: Plate was flooded with Frazier’s Developer
negative

28. LAB 16: Urease, SIM agar, Citrate

29. UREASE
UREASE TEST: Urease is an enzyme that breaks the carbon-nitrogen bond of amides (e.g. urea) to form carbon dioxide, ammonia, and water. Members of genus Proteus are known to produce urease. When urea is broken down, ammonia is released and the pH of the medium increases (becomes more basic). This pH change is detected by a pH indicator that turns pink in a basic environment. A pink medium indicates a positive test for urease.

30. SIM agar SIM = Sulfide, Indole, Motility.
INDOLE TEST: Indole is a component of the amino acid tryptophan. Some bacteria have the ability to break down tryptophan for nutritional needs using the enzyme tryptophanase. When tryptophan is broken down, the presence of indole can be detected through the use of Kovacs' reagent. Kovac's reagent, which is yellow, reacts with indole and produces a red color on the surface of the test tube.

31. SIM agar

32. MOTILITY Motile bacterium Non-motile bacterium (e.g. Staph aureus)
(e.g. Pseudomonas aeruginosa)

33. Citrate: The Simmon’s Citrate medium tests the ability of the
bacteria culture to be able to use citrate as the sole C source.
Bacteria that are able to produce the enzyme citrase are able to
transport the citrate into the cell and use it as a source of C.
Since the medium does not contain any other source for C, only
those bacteria that can produce citrase are able to grow in this
medium.
When cultures are able to use the citrate they break it down,
producing sodium bicarbonate, which changes the pH of the
medium to alkaline.
The pH indicator in the medium (bromothymol blue) changes to a
blue color from its original green color. +

34. LAB 17: Carbohydrate Utilization

35. Lab 17: KIA medium
C = Uninoculated 3 = Glucose fermenter + H2S producer
1 = Non-fermenter 4 = Glucose+Lactose fermenter, gas
2 = Glucose fermenter 5 = Gluc + Lact ferm + H2S producer

36. Lab 17: Fermentation of Carbohydrates
F- tubes

37. SUGAR Fermentation
Detection is based on acid production due to sugar fermentation. The pH indicator is PHENOL RED. Phenol red turns yellow under acidic conditions. Hence, yellow means a positive result.

38. The ability to ferment specific sugars is dependant on the ability of the
bacterium to produce the specific enzymes required for the
transport and metabolism of that particular sugar.
Thus fermentation of various sugars can be used to characterize bacteria.
The F-tubes use phenol red in the medium as pH indicator and the use
of inverted tubes to detect production of gases.
Results are recorded as Negative (no metabolism); Acid (+ reaction);
Acid + Gas (+ with gas production).

39. LAB 18: Unknown & Single Colony Isolation
Know how to use the Dichotomous Key to identify a bacterium based on morphology, Gram staining, endospore production, and various metabolic reactions. See p.58-61of lab manual.

41. LAB 19: Pour Plate Pour Plate Technique Serial Dilution
Colony Forming Unit (CFU)
Quantification of Bacteria in Cell/ml

42. Lab 19: Pour Plate Dilution Series: 100 10-1 10-2 10-3 10-4 (Dilution)
Bacteria Enumeration
Dilution Series:
(Dilution)
1ml
1ml
1ml
1ml
TMTC * (CFU)
*Best CFU
CFU = 100
Dilution = 1000
Hence 100 X 1,000 =
100,000 = 1x105
(1: : : : :10,000)

43. Bacteria Enumeration 1x10-5 1x10-6
Cell /ml= (CFU X dilution factor) / volume

44. LAB 20: Most Probable Number
MPN method, MPN table
Durham tubes
Presumptive, Confirmed, and Completed tests

45. Lab 20: Most Probable Number (MPN)
Bacteria Enumeration (Presumptive)
MPN method:
1st- Presumptive test: growth on lauryl tryptose broth
2nd - Confirmed test: on Eosine-Methylene Blue Agar (EMB)
3rd - Completed tests

46. LAB 21: Phage Characterization and Quantification
Plaque, Plaque Forming Unit (PFU)
Serial Dilution, Phage quantification
T1phage

47. BACTERIOPHAGE
1x10-4 Dilution
Plaque
(clear zone)
1x10-6 Dilution

48. LAB 22: Bacterial Aggutination & Immunoprecipitation

49. Immunoprecipitation
- is the reaction between a soluble antigen and its specific antibodies
soluble antigens are smaller and in solution; complexing with antibodies make these
bigger and they fall out of solution as a precipitate –visible to the eye.
Antibody specificity known (toxin, protein, etc.)
Antigen presence or identity not known (?)
Precipitationreaction between antibody and soluble antigen

50. Immunoprecipitation Antibody specificity known (toxin, protein, etc.)
Antigen presence or identity not known (?)
Precipitationreaction between antibody and soluble antigen

51. Immunoprecipitation

52. Reaction of nonidentity
Immunoprecipitation
Reaction of
identity
Reaction of nonidentity

53. LAB 23:Staphyloslide Latex Test Kit
Example of Agglutination

54. ? agglutination no agglutination Bacterial agglutination S. aureus
S. epidermidis ?

55. Mark your bacterial agglutination cards
Bacterial agglutination (new procedure). #1
Mark your bacterial agglutination cards
S. aureus
S. epidermidis

56. Mix the latex agglutination reagent dropper bottle
Bacterial agglutination #2
Mix the latex agglutination reagent dropper bottle
and dispense one drop onto each circle
S. aureus
S. epidermidis

57. Bacterial agglutination#3
Using a sterile toothpick , pick up and smear 1 suspect colony from your negative control in the proper ring. #4
Using a NEW sterile toothpick , pick up and smear 1 suspect colony from your positive control in the proper ring. #5
Using a NEW sterile toothpick , pick up and smear 1 suspect colony from your unknown in the proper ring.
S. aureus
S. epidermidis

58. Bacterial agglutination (Part B).#6
Pick up and gently rock the card for 20 seconds and observe for agglutination under normal lighting conditions
S. aureus
S. epidermidis ?