Lab Practical #3

Front 1

What is the difference in the macroscopic view of yeast and mold?

Back 1

Mold has a hairy, mossy look while yeast is white, creamy, and moist and smells like yeast.

Front 2

What is the microscopic difference between mold and yeast?

Back 2

Under the microscope yeast is always oval, while mold has various shapes, hyphae,etc.

Front 3

Why is Coccidiodes immitis considered to be a dimorphic fungus?

Back 3

Because it can only grow as yeast under certain environmental conditions.

Front 4

What are the growth differences between fungus and bacteria?

Back 4

Fungi grow as either yeasts or molds and are eukaryotic unlike bacteria which are prokaryotic.

Front 5

Define Blastospore

Back 5

A newly produced cell by yeast reproducing asexually by budding.

Front 6

Define Pseudohyphae

Back 6

Successive blastospores remaining attached to the original cell.

Front 7

Define Septate hyphae

Back 7

Fungal hyphal filaments that are separated by a crosswall.

Front 8

What is the difference between vegetative hyphae and aerial hyphae?

Back 8

Vegetative hyphae penetrates while aerial hyphae grow on the top of the agar's surface.

Front 9

What is the difference between sporangiospores and conidiospores?

Back 9

Sporangiospores are produced at the end of aerial hyphae. Conidiospores are formed on hyphae called conidiospores can be one-celled or multi-celled.

Front 10

how are molds identified in the laboratory?

Back 10

Pigment, Height, Slide Cultures

Front 11

Define Bacteriophage:

Back 11

Viruses that infect bacteria

Front 12

Define Lytic

Back 12

Lysis, Explode, burst

Front 13

Define Plaque

Back 13

Clear area on the agar represented by lysed E. coli

Front 14

What is the purpose for making dilutions of the T-4 virus?

Back 14

To get a countable plate

Front 15

What equation is used to calculate the titer of phage?

Back 15

Plaque Count X Dilution Factor X Sample Amount= PFU/mL

Front 16

Define obligate intracellular parasite

Back 16

They can grow only inside another living host cell.

Front 17

Define the Lytic Cycle

Back 17

Viruses burst open their bacterial host once the appropriate number of viruses has been synthesized, killing the bacteria.

Front 18

How does a medium used for bacterial growth differ from media used for bacteriophage growth?

Back 18

Bacteriophages can only survive in molten agar, not in normal media.

Front 19

What was the purpose of E. coli in the viral plaque experiment (Ex. 14)?

Back 19

E. coli was the host.

Front 20

Differentiate between Staphylococcus and Streptococcus by the catalase test.

Back 20

Staphylococcus will bubble, meaning it has catalase to break down the hydrogen peroxide. Streptococcus will not bubble because it does not have the catalase enzyme.

Front 21

What is the principle of the catalase test and what reagent is used?

Back 21

The test is used to determine whether or not catalase is present. Catalase will break down the hydrogen peroxide (reagent) and produce bubbles that are visible to the naked eye.

Front 22

What is the principle and the reagents used in the coagulase test?

Back 22

Reagent is rabbit plasma...if coagulase is present there will be clumping.

Front 23

What are the results for Staphylococcus aureus in the coagulase and it's reaction on Mannitol Salt agar?

Back 23

Coagulase positive.
Positive On Mannitol Salt Agar.

Front 24

What are the results for Staphylococcus epidermidis in the coagulase and it's reaction on Mannitol Salt agar?

Back 24

Coagulase negative.
Negative on mannitol salt agar.

Front 25

How is Mannitol Salt Agar both a selective and a differential media?

Back 25

It is selective because it determines what can grow because of the high salt concentration and differential because it determines what ferments mannitol because it will turn hot pink.

Front 26

What is the pigmentation of Micrococcus luteus?

Back 26

Yellow.

Front 27

What are the results of the nitrate test and glucose fermentation for Micrococcus luteus?

Back 27

Negative for nitrate reduction.
Negative for glucose fermentation.

Front 28

What are the results of the nitrate test and glucose fermentation for Micrococcus roseus?

Back 28

Positive for nitrate reduction.
Negative for glucose fermentation.

Front 29

What is the pigmentation of Micrococcus roseus?

Back 29

Pink.

Front 30

Staphylococcus and Micrococcus are what type of bacteria?

Back 30

Gram Positive Cocci in clusters.

Front 31

Where is Staphylococcus and Micrococcus found normally on the body?

Back 31

On the Skin and Mucous membranes.

Front 32

What is a carrier?

Back 32

Someone who harbors the pathogen but shows no signs and symptoms.

Front 33

What is MRSA?

Back 33

Isolates that have become resistant to penicillin derivatives.

Front 34

What does nosocomial mean?

Back 34

Hospital acquired infection.

Front 35

Name two substances that Staphylococcus aureus produce to cause disease.

Back 35

Exotoxins and enzymes

Front 36

When do Staphylococcus epidermidis and Micrococcus cause disease?

Back 36

In compromised tissues.

Front 37

What are the types of hemolysis and what do they look like?

Back 37

Alpha: Brownish green
Beta: Bright Yellow
Gamma: Looks like normal bacteria growth

Front 38

Why do you use the streak stab method for blood agar inoculations?

Back 38

Because it enhances the appearance.
Microaerophiles will find their area of oxygen easier.

Front 39

Identify the Alpha Streptococcus and beta Streptococcus given the appropriate biochemical test...

Back 39

Optochin for Alpha:
sensitive= Streptococcus pneumoniae; resistant= Streptococcus mitis.
Beta= Bacitracin
Sensitive: Streptococcus pyogenes; resistant= group c streptococcus

Front 40

Differentiate the Enterococcus from other alpha hemolytic streptococcus...

Back 40

Enterococcus turns black (+) during the bile esculin test while the others are negative. Enterococcus is also resistant to both the optochin and bacitracin tests.

Front 41

How do the appearances of the colonies of Staphylococcus and Streptococcus differ?

Back 41

Staphylococcus=clusters
streptococcus= lines and pairs

Front 42

Which enzyme helps differentiate all staphylococcus from streptococcus?

Back 42

Catalase

Front 43

How did Lancefield divide the beta-hemolytic streptococci into groups?

Back 43

Based on the C polysaccharides extracted from the cell walls.

Front 44

What is the species name of Lancefield Group A streptococcus?

Back 44

Streptococcus Pyogenes

Front 45

What is the species name of Lancefield Group B streptococci?

Back 45

Streptococcus agalactiae

Front 46

Where are Enterococcus normally found in the body?

Back 46

G.I. Tract

Front 47

Define VRE

Back 47

Vancomycin Resistant Enterococcus- nosocomial acquired strains that have acquired resistance to vancomycin.

Front 48

Define Viridans Streptococci

Back 48

Alpha hemolytic streptococci that produce green hemolysis.

Front 49

Name a disease that Group A Strep causes...

Back 49

Strep Throat

Front 50

Name a disease that Group B Strep causes...

Back 50

Neonatal septicemia

Front 51

Name a disease that Enterococcus causes....

Back 51

Urinary Tract Infection

Front 52

Name a disease that Streptococcus pneumoniae causes...

Back 52

Community-acquired pneumonia

Front 53

Name a disease that viridans streptococci causes...

Back 53

Dental Cavities

Front 54

Explain how CNA and MacConkey agar aid in the identification of your mixed unknown...

Back 54

CNA only grows gram (+) bacteria
MacConkey grows gram (-) bacteria

Front 55

Differentiate bacteria that grow on MacConkey by their ability to ferment lactose...

Back 55

If the bacteria can ferment lactose it will turn hot pink.