Pre-Labs

How much media is needed to prepare each of the following?: agar slant, agar plate, broth tube, agar deep

• Slant: 7 mL

• Plate: 20 mL

• Broth: 7 mL

• Deep: 50% of the test tube

Complex/undefined media

General growth media in which the exact chemical composition is not known

Broths

Used to grow microbes when a large number of cells are required

Agar slants

Used mainly for growing stock cultures

What four factors affect microbial growth? 

• Type of growth medium

• Incubation time

• Incubation temperature

• pH of the medium

What are the three fundamental skills needed in a microbiology lab? 

• Good hand-washing technique

• Good aseptic transfer technique

• Good media-preparing technique

Name two ways you can isolate a colony on an agar plate. 

• Spread plate (pour plate)

• Quadrant streak plate

Mutualism

The symbiotic organism and the host both receive benefit(s) from the relationship

Free-living organisms

Organisms that do not live in or on a host

Opportunistic organisms

Capable of producing a diseased state, if introduced into a suitable part of the body

Saprophytic

Living off dead, decomposed organic matter

Pathogens

Organisms that do cause disease and damage the host

Most organisms do not cause infections in humans (T/F?)

True

What are the appropriate settings to autoclave sufficiently? 

 121 Celsius ; 15 psi (pressure); 15 min

A pure culture is necessary to perform tests for identification purposes; and, it is usually grown in a broth or slant medium (T/F?)

True

Mixed cultures only have one type of organism (T/F?)

False

Identify the growth in media to the media type: pellicle

Broth

Identify the growth in media to the media type: filiform with a smooth edge

Agar slant

Identify the growth in media to the media type: turbid

Broth

Identify the growth in media to the media type: smooth, entire

Agar plate

Identify the growth in media to the media type: sediment

Broth

Define the term for growth in broth culture: flocculent

Suspended chunks or pieces

Define the term for growth in broth culture: sediment

Growth on the bottom

Define the term for growth in broth culture: ring

Growth at top around the edge

Define the term for growth in broth culture: pellicle

Membrane at the top

Define the term for growth in broth culture: uniform fine turbidity

Evenly cloudy throughout

Define the term for growth on slant culture: filiform

Smooth texture with solid edge

Define the term for growth on slant culture: spreading edge

Solid growth seeming to radiate throughout

Define the term for growth on slant culture: transparent

Almost invisible or easy to see light through

Define the term for growth on slant culture: friable

Rough texture with a crusty appearance

Define the term for growth on slant culture: pigmented

Produces a colored growth

Identify the growth in media to the media type: umbonate

Agar plate

Identify the growth in media to the media type: friable

Agar slant

Identify the growth in media to the media type: flocculent

Broth

Identify the growth in media to the media type: filamentous whole colony shape

Agar plate

Identify the growth in media to the media type: raised

Agar plate

Identify the following margins:

1. Entire (smooth)

2. Undulate (wavy)

3. Lobate (lobed)

4. Filamentous (unbranched strand)

5. Irregular

Identify the following slant growths:

1. Filiform (smooth, even)

2. Beaded

3. Echinulate (spiny)

4. Filamentous (unbranched strands)

5. Rhizoid (branched)

Identify the following elevations:

1. Flat

2. Raised

3. Plateau

4. Convex

5. Umbonate

The image below demonstrates a pellicle and sediment (T/F?)

True

Identify the following colony shapes:

1. Round

2. Erose

3. Spindle

4. Irregular

What is the practical limit of magnification of the light microscope?

1300X

Identify the organisms to its correct common name: Clonorchis sinensis

Chinese liver fluke

Identify the organisms to its correct common name: Trichinella spiralis

Pork worm

Identify the organisms to its correct common name: Taenia pisiformis

Tapeworm

Identify the organisms to its correct common name: Fasciola hepatica

Common liver fluke

Identify the organisms to its correct common name: Enterobius vermicularis

Pinworm

Identify the structure to the group: encysted larvae

Pork worm

Identify the structure to the group: scolex and proglottids

Tapeworm

Identify the structure to the group: oral sucker and cercariae

Chinese liver fluke

Identify the structure to the group: hypostome

Tick

Micrometers can also be called microns (T/F?)

True

Identify the cellular structure of organelle to the genus that has it: cilia

Paramecium

Identify the cellular structure of organelle to the genus that has it: pseudopods

Amoeba

Identify the cellular structure of organelle to the genus that has it: kinetoplast

Trypanosoma

Identify the cellular structure of organelle to the genus that has it: chloroplasts

Spirogyra

Identify the cellular structure of organelle to the genus that has it: hyphae with conidia

Aspergillus

Identify the microbe to the appropriate category: Plasmodium vivax

Protozoa

Identify the microbe to the appropriate category: Diatoms

Algae

Identify the microbe to the appropriate category: Candida albicans

Yeasts

Identify the microbe to the appropriate category: Rhizopus

Molds

Identify the microbe to the appropriate category: Giardia lamblia

Protozoa

What is the total magnification when using the low power objective with a 10X eyepiece? 

100X

Numerical aperture

The measure of the ability of a lens to “capture” light coming from the specimen and use it to make the image

Condenser

Structure of a microscope concentrates the light onto the specimen

Resolving power

Actual measurement of how far apart two points must be for the microscope to view them as separate points

Parfocal

Ability of the microscope to stay in relative focus as the objective lenses are changed from one to another

Field/field of vision

The round lit area you see when looking through the microscope

A phase contrast microscope illuminates the specimen and its parts at various levels of light intensities (contrast) because the light waves are both in phase and out of phase (T/F?)

True

What is the resolution of a compound, binocular, bright-field microscope?

 0.2 µm

Acidic stains can also be called negative stains (T/F?)

True

Methylene blue is a basic stain (T/F?)

True

Safranin is an acidic stain (T/F?)

False

A pair of two rods linked end-to-end are called:

Diplobacilli

The counter stain for the Gram stain is safranin (T/F?)

True

Heat-fixing can distort cell shape, arrangement, and size (shrinkage) (T/F?)

True

Acidic stains

This type of stain is negatively charged and repels the negative charge of the bacterial cell, thus leaving the organism unstained with a colored background

Auxochrome

This is the charged portion of the chromogen

Basic stain

This type of stain is attracted to the negative charge of the bacterium and will dye the bacterium a certain color and leave the background white

Chromophore

This is the portion of the chromogen that has color

Chromogen

This is the colored molecule of a stain (usually a benzene derivative)

A chain of round cells is called a:

Streptococci

Nigrosin is an acidic stain (T/F?)

True

Congo red is a basic stain (T/F?)

False

The acid-fast stain is a differential stain (T/F?)

True

The basic stain that stains the bacterium inside the capsule in the capsule stain procedure is:

Maneval’s stain

What color are the vegetative cells in the endospore stain?

Red or pink

Central endospore

The endospore is in the middle of the cell

Terminal endospore

The endospore is on the end of the cell

Subterminal endospore

The endospore is between the middle and end of the cell

The Kinyoun acid-fast staining method requires heat for at least five minutes (T/F?)

False

A smear for the capsule stain requires heat-fixing (T/F?)

False

What are the two acid-fast staining methods?

Kinyoun (K) and Ziehl-Neelsen (ZN)

A counter stain for the acid-fast stain is:

Methylene blue

Peritrichous (flagella arrangement)

Flagella covering the entire cell surface of the bacterium

Monotrichous or polar (flagella arrangement)

A single flagellum found at one end of the bacterium

Amphitrichous (flagella arrangement)

Flagella at both ends of the bacterium

Lophotrichous (flagella arrangement)

Tufts of flagella at one end of the bacterium

The primary stain the endospore stain is:

Malachite green

In MSA the inhibitor is:

High salt content