Microbiology Lab Practical 2 - Staph, Strep, Intestinal Pathogens

Front 1

Enriched media that contains 10% NaCl.

Back 1

m-Staphylococcus Broth

Front 2

Name the organism that prefers higher salt concentration.

Back 2

Staphylococcus

Front 3

What does the higher salt concentration do to other organisms?

Back 3

Inhibits most other organisms

Front 4

Name the components of Mannitol Salt Agar.

Back 4

Mannitol, 7.5 % NaCl and Phenol Red Indicator

Front 5

Mannitol, 7.5 % NaCl and Phenol Red Indicator

Back 5

Mannitol Salt Agar components

Front 6

What happens if the Mannitol ferments to produce acid?

Back 6

The phenol red changes color from red to yellow.

Front 7

Why does phenol red changes color from red to yellow?

Back 7

Mannitol was fermented.

Front 8

Staphylococcus Medium 110 (SM110)

Back 8

Mannitol and 7.5 % NaCl

Front 9

Mannitol and 7.5 % NaCl

Back 9

Staphylococcus Medium 110 (SM110) components

Front 10

Name the advantage of SM110 over MSA.

Back 10

SM110 favors colony pigmentation by different strains of S. Aureus

Front 11

Name the media that favors colony pigmentation by different strains of S. Aureus.

Back 11

SM110 (Staphylococcus Medium 110)

Front 12

These patterns differentiate microorganisms based on their reactions to blood.

Back 12

Hemolysin patterns on Blood Agar Plates

Front 13

Name the three hemolysin patterns.

Back 13

Alpha Hemolysis, Beta Hemolysis and Gamma Hemolysis

Front 14

Alpha Hemolysis, Beta Hemolysis and Gamma Hemolysis

Back 14

Hemolysin patterns on Blood Agar Plates

Front 15

Hemolysin pattern that has partial blood hemolysis and partial clearing around colony.

Back 15

Alpha Hemolysis

Front 16

Hemolysin pattern that has partial clearing around colony that appears green due to partial reduction of hemoglobin in blood.

Back 16

Alpha Hemolysis

Front 17

Explain why partial clearing around colony appears green in Alpha Hemolysis.

Back 17

Partial reduction of hemoglobin in blood.

Front 18

Hemolysin pattern that has complete blood hemolysis and complete clearing around colony.

Back 18

Beta Hemolysis

Front 19

Hemolysin pattern that has no blood hemolysis and no zone of clearing around colony.

Back 19

Gamma Hemolysis

Front 20

Name toxin responsible for Beta Hemolysis.

Back 20

Hemolysin

Front 21

Name the organism that always test positive during a Coagulase Test.

Back 21

S. Aureus

Front 22

Procedure includes inoculating small plasma tube with organism and incubating at 37 degree water bath overnight for this test.

Back 22

Coagulase Test

Front 23

After incubating inoculated plasma tube at 37 degree water bath overnight, the plasma becomes clumpy or solidifies. Is this a positive or negative reaction?

Back 23

Positive reaction

Front 24

Bacteria that caused plasma to clump or solidify is called...

Back 24

Coagulase positive bacteria

Front 25

Coagulase positive bacteria

Back 25

Bacteria that caused plasma to clump or solidify.

Front 26

Explain why Coagulase Test is valid for only gram + staph bacteria.

Back 26

Some gram - bacteria can cause false positive reactions and clotting mechanism is not due to coagulase.

Front 27

What is the typical appearance of S. Aureus on MSA plate?

Back 27

S. Aureus turns yellow due to fermentation

Front 28

S. Aureus turns yellow due to fermentation when grown on this type of plate.

Back 28

MSA Plate

Front 29

What is the typical appearance of S. Aureus on Blood Agar plate?

Back 29

Beta Hemolysis (Complete blood hemolysis and complete clearing)

Front 30

S. Aureus when grown on this type of plate

Back 30

Blood Agar Plate

Front 31

What is the typical result of S. Aureus in the Coagulase Test?

Back 31

Coagulase Positive

Front 32

Describe typical gram stain, cellular morphology and arrangement in Streptococci.

Back 32

Gram Positive Cocci in pairs and chains

Front 33

Name the organism that is gram positive cocci, in pairs and chains.

Back 33

Streptococci

Front 34

Biochemical test that is used to differentiate between Strep and Staph.

Back 34

Catalase Test

Front 35

In Catalase Test, does Strep test positive or negative?

Back 35

Negative

Front 36

In Catalase Test, does bubbling from hydrogen peroxide indicate a positive or negative reaction?

Back 36

Positive

Front 37

In Catalase Test, does Staph test positive or negative?

Back 37

Positive

Front 38

List the six (6) screening tests for streptococci.

Back 38

1) Catalase Test
2) Hemolysis on BA plate
3) Bacitracin Test
4) Optochin Test
5) Bile Esculin Test
6) 6.5% Salt Tolerance Test

Front 39

Name the type of Strep that completes Alpha hemolysis on BA plate.

Back 39

Streptococcus pneumoniae

Front 40

Name the type of Strep that completes Beta hemolysis on BA plate.

Back 40

Streptococcus pyogenes

Front 41

Name the type of Strep that completes Gamma hemolysis on BA plate.

Back 41

Enterococcus faecalis

Front 42

In Hemolysis on BA plate Test, what type of blood is used due to its consistent hemolytic patterns of Strep?

Back 42

Sheep Blood

Front 43

Name the test used to differentiate Beta Hemolytic Group A Streptococcus (BSA).

Back 43

Bacitracin Test

Front 44

Name the organism that causes acute pharyngitis.

Back 44

Beta Hemolytic Group A Streptococcus (BSA)

Front 45

What is another name for acute pharyngitis?

Back 45

Streptococcus pyogenes

Front 46

In Bacitracin Test, was is placed on an agar plate?

Back 46

Bacitracin disk

Front 47

In Bacitracin Test, what is the Bacitracin disk?

Back 47

An antibiotic

Front 48

In Bacitracin Test, what does the Bacitracin disk do?

Back 48

Inhibits bacterial growth

Front 49

In Bacitracin Test, how many mm constitutes a presumptive identification of Beta Hemolytic Group A Streptococcus (BSA)?

Back 49

Zone of clearing of 10 mm or more around the disk.

Front 50

Name the test that constitutes a presumptive identification of Beta Hemolytic Group A Streptococcus (BSA).

Back 50

Bacitracin Test

Front 51

Name the test used to differentiate Streptococcus Pneumoniae from other Alpha Hemolytic Streptococci.

Back 51

Optochin Test

Front 52

Name the only Streptococcus that is susceptible to Optochin.

Back 52

Streptococcus Pneumoniae

Front 53

In Optochin Test, what is the chemical name for the Optochin disk?

Back 53

Ethylhydrocupreine hydrochloride

Front 54

Ethylhydrocupreine hydrochloride is the chemical name for __________.

Back 54

Optochin

Front 55

In Optochin Test, how many mm constitutes a presumptive identification of Streptococcus Pneumoniae?

Back 55

Zone of inhibition of 14mm or more around disk.

Front 56

Name the test that constitutes a presumptive identification of Streptococcus pneumoniae.

Back 56

Optochin Test

Front 57

Name the test that constitutes a presumptive identification of Enterococcus faecalis and Group D Streptococcus.

Back 57

Bile Esculin Test

Front 58

Name the test that hydrolyzes esculin (glycoside composed of esculetin and glucose).

Back 58

Bile Esculin Test

Front 59

In Bile Esculin Test, what does esculetin react with?

Back 59

An indicator (ferric citrate)

Front 60

In Bile Esculin Test, describe end result when esculetin reacts with indicator (ferric citrate).

Back 60

Form a dark brown phenolic iron complex

Front 61

Name the test that forms a dark brown phenolic iron complex.

Back 61

Bile Esculin Test

Front 62

In Bile Esculin Test, do Enterococcus faecalis and Group D Streptococcus grow well on this slant?

Back 62

Yes

Front 63

In Bile Esculin Test, is a slant that is more than half dark considered to be positive or negative.

Back 63

Positive

Front 64

Name the test based on the ability of Enterococcus faecalis and Group B Streptococcus to grow in 6.5% salt broth.

Back 64

Salt Tolerance Test

Front 65

In Salt Tolerance Test, state if turbidity (yellow discoloration) is positive or negative.

Back 65

Positive

Front 66

In Salt Tolerance Test, describe a positive result.

Back 66

Turbidity (yellow discoloration)

Front 67

Name the test that runs side by side with Bile Esculin Test.

Back 67

Salt Tolerance Test

Front 68

Name the three selective differential media for isolation.

Back 68

1) MacConkey Agar
2) TSI Slant
3) Urea Broth

Front 69

Name the six gram - intestinal pathogens.

Back 69

1) Salmonella
2) Shigella
3) Escherichia
4) Enterobacter
5) Proteus
6) Pseudomonas

Front 70

What is the fermentation characteristic that separates Salmonella and Shigella from Coliforms?

Back 70

Inability to ferment lactose

Front 71

Name the intestinal pathogens that cannot ferment lactose.

Back 71

Salmonella & Shigella

Front 72

Intestinal pathogens that ferment lactose on MacConky Agar Plate produce what color?

Back 72

Red/Black

Front 73

Intestinal pathogens that do not ferment lactose on MacConky Agar Plate produce what color?

Back 73

No color

Front 74

Intestinal pathogens that ferment both glucose and lactose on a TSI Slant produce what color?

Back 74

Yellow

Front 75

Name the intestinal pathogens that produce ALL yellow color on a TSI Slant.

Back 75

Coliforms

Front 76

Intestinal pathogens that ferment glucose and not lactose on a TSI Slant produce what colors?

Back 76

Red Slant/Yellow Butt

Front 77

Name the intestinal pathogens that produce a red slant and yellow butt on a TSI Slant.

Back 77

Salmonella, Shigella and Proteus

Front 78

Intestinal pathogens that do not ferment both glucose and lactose on a TSI Slant produce what colors?

Back 78

Red

Front 79

Name the intestinal pathogens that produce ALL red color on a TSI Slant.

Back 79

Pseudomonas

Front 80

Intestinal pathogens that produce a black precipitate is evidence for what?

Back 80

Hydrogen Sulfide production

Front 81

Name the intestinal pathogens that produce hydrogen sulfide.

Back 81

Salmonella and Proteus

Front 82

Name the enzyme that intestinal pathogens contain for Hydrogen Sulfide production.

Back 82

Cystein Desulferase

Front 83

Intestinal pathogens that produce a hot pink color in urease deems them positive or negative?

Back 83

Positive

Front 84

Name the intestinal pathogens that are positive for urease.

Back 84

Proteus

Front 85

Name the intestinal pathogens that are negative for urease.

Back 85

Coliforms

Front 86

Name the 3 reaction patterns seen on media for intestinal pathogens.

Back 86

1) Test for glucose/lactose fermentation
2) Test for Hydrogen Sulfide production
3) Test for Gas production

Front 87

Describe how gas production can be determined for intestinal pathogens.

Back 87

Cracks and lifting of slant (from bottom of tube)

Front 88

Name the components of Triple Sugar Iron Agar.

Back 88

Iron Salts, Glucose and Lactose

Front 89

When medium turns yellow during the 1st part of incubation period of intestinal pathogens, it then changes to red later due to increased alkalinity. What is this called?

Back 89

Alkaline reversion

Front 90

Describe Alkaline Reversion.

Back 90

Medium turns yellow during 1st incubation, then turns red due to increased alkalinity.