Microbiology Unit 2 Lab

Front 1

aerotolerance

Back 1

the ability or inability of an organism to grow in the presence of oxygen

Front 2

Obligate (strict) aerobes

Back 2

Need oxygen
seen at the top of the medium

Front 3

Facultative anaerobes

Back 3

Can grow in the presence or absence of oxygen
live throughout the medium

Front 4

Aerotolerant anaerobes

Back 4

Respire anaerobically even in the presence of oxygen
live throughout the medium

Front 5

Microaerophiles

Back 5

Can live only in environment containing lower than atmospheric levels of oxygen
live near the middle of the medium

Front 6

Obligate (strict) anaerobes

Back 6

No oxygen-even small amounts of O2 are lethal
typically live in the lower half to two-thirds of the medium

Front 7

Capnophiles

Back 7

Can survive only if CO2 levels are elevated

Front 8

Streak Plate technique

Back 8

Use a four streak pattern in quadrants, sterilizing the loop for each pass.
Allows for individual cells or colony forming units to separate and grow into individual pure colonies

Front 9

Simple Stain

Back 9

Most bacteria have a negative charge. The stains Methyl Blue, Crystal Violet and Safranin will form a bond.

Front 10

Heat Fix

Back 10

Kills the bacteria
Causes bacteria to adhere to the slide
Coagulates the cytoplasmic proteins.

Front 11

Negative Stain

Back 11

To determine morphology and cellular arrangement.
The dye and bacteria are both negative charge so the bacteria repels the dye and remains unstained against the dark background
Nygrosin and Congo Red

Front 12

Morphology

Back 12

Cell shape and arrangement

Front 13

Cocci (singular)
Coccus

Back 13

Round sphere shape

Front 14

Bacilli (singular)
Bacillus

Back 14

Rods

Front 15

Spirilla (singular)
Spirillum

Back 15

Spiral shape

Front 16

Vibrios

Back 16

Slightly curved rods

Front 17

Coccobacilli

Back 17

Short rods

Front 18

Spirochetes

Back 18

flexible sprials

Front 19

Pleomorphism

Back 19

Variety of cell shapes

Front 20

Diplococcus

Back 20

two cocci daughter cells remain attached

Front 21

Diplobacilli

Back 21

two bacilli daughter cells remain attached

Front 22

Streptococcus

Back 22

a coccus chain

Front 23

Streptobacillius

Back 23

Bacillus chain

Front 24

Tetrad

Back 24

Group of four cells (cocci only)

Front 25

Sarcina

Back 25

Group of eight cells (cocci only)

Front 26

Staphyloccus

Back 26

cluster of coccus cells

Front 27

Gram Stain

Back 27

A method of staining that differentiates between Gram (-) and Gram (+) bacteria. The results of this stain depend upon the cell wall of the bacterium.

Front 28

Gram Stain's 4 reagents in order

Back 28

Primary Stain - Crystal Violet
Mordant - Gram's Iodine
Decolorizing Agent - 95% Ethanol
Counterstain - Safranin

Front 29

In Gram Staining, what is the purpose for the Ethanol?

Back 29

Decolorizing Agent; the most critical step of Gram staining.

It is a lipid solvent, so the outer membrane of the Gram negative bacteria will melt away and washes out the dark purple stain and leaves the Gram negative bacteria colorless.

Front 30

When Gram Staining what is the purpose of Safranin?

Back 30

Because the outer membrane of the Gram negative bacteria has been melted away and the purple is gone, safranin will stain the Gram (+) cells pink.

Front 31

Acid Fast Stain shows this

Back 31

Use to detect cells capable of retaining a primary stain when treated with an acid alcohol. Used to identify Mycobacterium

Front 32

Mycobacterium

Back 32

Have Mycolic Acid in the cell wall (a waxy substance)
Use the Acid Fast Stain to identify

Front 33

Endospore Stain

Back 33

Use to detect the presence of spores in bacterial cells
Smear, air dry, heat fix
With steam and Malachite green flood for 5-7 min
Rinse
Flood with Safrinin 1-2 min
Rinse; blot

Front 34

Endospore

Back 34

a dormant stage of bacteria to survive in a poor environment

Front 35

Hanging Drop stain

Back 35

To observe Motility (flagella), a wet mount preparation on a special slide (has a depression) with a cover slip. A drop of water is placed on the cover slip (four corners have a thin dot of petroleum jelly) the microbe is transferred to the cover slip. NO STAIN IS USED
Invert the slide for viewing

Front 36

Catalase Test

Back 36

To identify organisms that produce the enzyme catalase, used to break down H2O2 into H2O + O2
(+) shows gas (O2)

Front 37

Citrate Test

Back 37

Test for possession of the enzyme Citrate-permease allows the organism to use citrate as a sole carbon source
Green medium changes to blue in (+) pH 7.6 or higher

Front 38

Fermentation; Starch Hydrolysis
Glucose

Back 38

If an organism can use glucose to produce pyruvate by glycolysis
Clear halo around colony (+)
Amylase enzyme

Front 39

Gelatinase Test

Back 39

Ability to produce gelatinases
Watery tube (+)
solidification of media (-)
(-) is the presence of gelatinase enzyme to hydrolyze gelatin

Front 40

Indole Test

Back 40

produce indole using enzyme tryptophanase
SIM method test for motility, NH3, and Indole
Add Kovak's Reagent which will react with the indole to produce quinoidal compound
Red= (+) bacteria has the enzyme
No Red = indole (-)

Front 41

Lipase Test (egg yolk)

Back 41

Lipid Hydrolysis (lipids are fats)
Lipases can hydorlyze fat, they break down the Triglycerides (glycerol + 3 Fatty Acid chains)
Pink = (-)
Clear zones =(+)

Front 42

Methyl Red/Vogues Proskauer Test
MR-VP

Back 42

A combination test to detect an organism capable of overcoming the buffer and lowering the pH
Red = (+)
Oranges and Yellows =(-)

Front 43

Motility Test
(H2S ?)

Back 43

Stab with a straight needle.
(+) shows diffuse growth radiating from the central stabline

Front 44

Starch Hydrolysis

Back 44

Ability to hydrolyze starch, enzyme amylase or glucosidase
Breaks down starch to get it into the cell
(+) clear zones
(-) blue/dk brown

Front 45

Urease Test

Back 45

ability to hydrolyze urea with urease break it into NH3 + CO2
Proteus have rapid urease activity (can cause urinary infection)
(+) pink

Front 46

Two differential stains

Back 46

Gram Stain
Acid Fast Stain

Front 47

List the steps of Acid Fast Stain

Back 47

Do smear, air dry, heat fix
Steam Fix with Carbol Fuchsin for 5-7 minutes
Rinse
Rinse with Acid Alcohol 1 min
flood with Methyl Blue 1-2 min
blot
(+) pink are acid fast
(-) blue

Front 48

describe the negative stain smear method for Capsular Staining

Back 48

put a drop of the bacteria toward the end of a clean slide.
put the ink (Nigrosin) a bit further toward the end.
use a second clean slide to drag first across the ink then adding the bacteria as you drag without stopping