MICROBIO LAB EXAM 2

Many bacterial species might contain the answers to all of the questions we as a population have been asking in ?

Medicine, Energy, Engineering.

How is bacteria named?

The first word is the genus (capitalized)

The second word is the species (not capitalized)

Both words are italicized or underlined if hand written.

Can also be named after the person that discovered them.

What is this bacterial nomenclature?

Staphylococcus aureus

What is this bacterial nomenclature?

Clostridium botulinum

What is this bacterial nomenclature?

Klebsiella pneumoniae.

What is this bacterial nomenclature?

Clostridium tetani.

What is this bacterial nomenclature?

Streptococcus pneumoniae.

What is this bacterial nomenclature?

Bordetella pertussis.

What is this bacterial nomenclature?

Neisseria gonorrhoeae

What is this bacterial nomenclature?

Neisseria gonorrhoeae

What are the 3 types of categorizing bacteria?

Phenotypic

Analytic

Genotypic

What is phenotypic classification?

Observable characteristics such as size, shape, or staining characteristics.

Describe gram positive gram stain.

Thick peptidoglycan wall, retaining many crystal violet stains.

Blue/purple color

Describe gram negative gram stain.

Thin peptidoglycan walls, retaining few crystal violet stains.

Red color under microscope.

What are the three shapes of bacterial organisms?

Bacilli

Cocci

Spirilla

What is Analytic classification? What does it include?

Identifies and assigns categories to a collection of data to allow for more accurate analysis.

Includes:

• Whole cell lipid analysis

• Cell wall fatty acid analysis

• Whole cell protein analysis via mass spectroscopy

• Enzyme and electrophoresis

Analytic classification requires:

Expensive machinery, specialized training, and often done only in special labs.

What is biochemical identification? What does it include/do?

Tests to determine what biochemical properties bacteria possess based on metabolic capacities.

Includes/does:

• Ability to ferment carbohydrates

• What carbon sources specific bacteria can use for growth

• The presence or absence of different enzymes in bacteria.

What is Immunological identification?

Based on Antigen / Antibody reactions.

Ex. ELISA test

What is Genotypic classification?

Based on diversities and uniqueness of genetic information in bacteria.

Precise method.

Can use bacterial DNA to determine the species or family of some bacteria.

• DNA fingerprinting

• Gene Sequencing

What is Bacterial classification? Examples? What do they all contain?

• Aerobic Gram-Positive Cocci

  • Catalse positive cocci (staphylococcus)

• Aerobic Gram-Positive Rods:

  • Actinomycetes

  • Miscellaneous

• Aerobic Gram-Negative Rods / Cocci / Curved Rods:

  • Largely pathogenic organisms (Neisseria gonorrhoeae, legionella pneumonia, etc.)

• Anaerobic Gram-Positive and Gram-Negative Bacteria:

  • Categorized further by shape (Clostridium perfringens)

What are the five I’s of microbiology?

Inoculation, Incubation, Isolation, Inspection, and Identification.

What is colony morphology?

The physical appearance and characteristics of bacterial colonies growing on agar.

What is a bacterial colony?

A visible group of bacteria growing together, usually from one original cell.

What is colony size?

The measurement of how large or small a bacterial colony is.

What are the common colony shapes?

Circular, irregular, filamentous, and rhizoid.

What is colony margin?

The outer edge or border of a bacterial colony.

What are common colony margins?

Entire (smooth), undulate (wavy), lobate (lobed), and filamentous.

What is colony elevation?

How high or raised a colony appears when viewed from the side.

What are common colony elevations?

Flat, raised, convex, umbonate, and crateriform.

What does colony pigmentation mean?

The color produced by a bacterial colony.

What does colony opacity describe?

How much light passes through a colony.

What are the three types of colony opacity?

Transparent, translucent, and opaque.

What is colony texture?

The surface appearance or consistency of a colony.

What are examples of colony textures?

Smooth, rough, mucoid, and dry.

What does a mucoid colony look like?

Slimy or sticky because of capsule or slime production.

Why is colony morphology important?

It helps with the preliminary identification of bacteria.

Can colony morphology alone identify bacteria?

No. Additional biochemical and laboratory tests are needed.

What is the slide culture technique?

A laboratory method used to observe fungal structures under a microscope.

What is the main purpose of slide culture?

To identify fungi by observing their microscopic structures.

Why is slide culture useful for identifying fungi?

It preserves the natural arrangement of fungal structures.

What type of medium is commonly used for slide culture?

Sabouraud dextrose agar (SDA).

What is the purpose of the coverslip?

It supports fungal growth and helps preserve structures for microscopic observation.

What fungal structures can be observed using slide culture?

Hyphae, spores, conidia, and conidiophores.

What are hyphae?

Thread-like structures that make up the body of a fungus.

What is mycelium?

A network or mass of fungal hyphae.

What are spores?

Reproductive structures that help fungi spread and reproduce.

What are conidia?

Asexual fungal spores that are not enclosed in a sac.

What are conidiophores?

Specialized fungal structures that produce and support conidia.

What is the purpose of lactophenol cotton blue?

It stains and helps visualize fungal structures under a microscope.

Why is microscopic examination important in fungal identification?

Different fungi have characteristic microscopic structures.

What is the difference between yeast and mold?

Yeasts are generally unicellular, while molds grow as multicellular hyphae.

What does Inoculate mean?

The process of introducing a microorganism into an environment in which they can grow.

What does Incubate mean?

The process of allowing microorganisms to grow at a constant optimal conditions over a period of time.

What is a pure culture?

Has a single known species (axenic)

What is mixed culture?

Has two or more identified species.

What is contaminated culture?

Has unwanted microorganisms of uncertain identity.

What is Isolation?

The separation of different microorganisms from each other.

Three major methods of isolation include?

Streak-plate method

Pour-plate method

Spread-plate method

What is Macroscopic inspection?

Where colonies on a solid medium or colonies in a broth culture are examined with the eyes.

What is microscopic inspection?

Viewing cells using a microscope.

What is the Identify process of the five I’s?

Accomplished by using the collective data gained from the inspection and identifying what the organism is.

CFU has to be between?

30-300

TNTC means?

Too numerous to count.

TFTC means?

Too few to count.

Total bacterial count equals?

count x dilution factor (CFU/ml)

What is dilution?

The process of decreasing the concentration of a solute in solution, usually by mixing with more solvent.