Microbiology lab midterm

According to the UTSA Handbook of Operating Procedures (HOP), graded work can only be made up or submitted late if this is due to documented: (check all that apply)

-military or government service -observance of a religious holiday -required participation in an official UTSA-sponsored event.

Koehler illumination is set up using the ____ X objective.

10

A Phenol Red Glucose Broth was inoculated and incubated for 20hours at body temperature. You observe that the broth is yellow and there is a bubble in the Durham tube. How would you record these results? What process has occurred?

A/G; fermentation

PRCB test EPI(s)

Acid and gas

Statins that lower cholesterol, antibiotics and fermentation end products like acids and alcohols are all products that benefit people and are produced by Fungi!

True

Students will be expected to review recordings and materials posted on Blackboard, and keep up with required completion of all assignments and posted due dates according to the class schedule.

True

The 4 quadrant streak plate method is a good technique to use when dealing with high density samples like a patient sample.

True

Using notes, another person or outside sources of any kind during an online proctored exam is considered cheating and will be reported to the office of academic dishonesty.

True

Your Unknown Identification project report is late if it is not submitted by the stated due date per the class schedule.

True

Based on the medium recipe given below, identify whether the given medium is defined or undefined. Ingredients: Sucrose 10 grams, Cysteine 5 grams, Magnesium chloride 5 grams, Agar 5 grams, Sheep Blood 50 ml, Distilled water 1000 ml

Undefined

Which of the following statements regarding the PRCB test are true? Please indicate all that apply.

-An observation of pink/no bubble after 24 hour incubation denotes a result of K. -A Durham tube is one of the indicators. The end products of interest (EPI) for this test are acid and gas. A result of A/-- denotes fermentation has occurred.

What items should be discarded into small white biohazard containers? Select all that apply.

-Cotton swabs -Pasteur pipettes -Wooden applicators

Select all of the following statements which are true.

-Never apply cosmetics or insert contacts lenses in the laboratory. -Never pipette anything by mouth. -Always clean your lab bench area before and after work with a disinfectant like Wescodyne.

This objective should be used to set up Koehler illumination

10x

VP test process

2,3 butanediol fermentation

Calculate the best limit of resolution for a microscope that utilizes a light wavelength of 500 nm and has the below Numerical aperture values.Assume a NA of the condenser at 0.9 (without oil) and 1.25 (with oil)HINT: The best LOR is using the maximum magnification and proper use of that objective. Typical N.A. Values 4x .1 10x .25 40x .65 100x 1.25

200 nm LOR= (wavelength)/(NA condenser + NA objective)

You have just viewed commercially prepared slides with immersion oil. List 2 specific actions you should take regarding the slides and/or your microscope before returning these items to their original places.

?

Which of the following facts about agar is true?

Agar is made from seaweed Agar solidifies at 40 Degrees Celsius

Think critically! A lab technician is making a batch of MRVP broth. Oops! They left out the phosphate buffer. Assuming you are testing members of the family that IMViC is designed to ID, what is the consequence of this mistake when interpreting your methyl red test result?

All species tested would appear positive for mixed acid fermentation. buffer added to to resist small changed in pH

VP test reagents

Aloha-naphthol, Potassium hydroxide

Citrate test EPI

Ammonia

In any stain/dye, the charged portion of the chromogen is the _________________ while the pigmented (colored) portion is the __________________.

Auxochrome, chromophore

Define the acronym BSL. What level of laboratory is our micro lab?

Bio safety level, 2

All bacterial cells can be stained as............ G- or G+

Both

Crystal violet stains these cells purple after just step 1 of Gram staining. G- or G+

Both

Citrate test indicator

Bromothymol blue

The type of media that contains 0% agar is a:

Broth

PRCB test substrate

Carbohydrate

Gram staining allows us to distinguish between bacteria based on differences in what specific cell structure?

Cell wall

Diplydium caninum, flea, praziquantel

Choose the answer that fills in the below blanks properly. The above scolex is from the species __________of the helminthe subphylum cestoda, and produces the egg packets seen on the right. This organism causes anal pruritits, loss of appetite and indigestion in humans, cats and dogs. The insect vector is the _____________. The drug of choice for this type of parasitic infection is ___________________.

Citrate test enzyme

Citrate permease

Matching: Hemolysis on blood agar Beta hemolysis

Complete clearing of RBCs

Shutter/diaphragm that controls the amount of light that will directly hit the slide on the stage and the angle of illumination. Has recommended values based on the objective used.

Condenser aperture diaphragm

This type of light microscopy uses light reflected off (not transmitted through) the sample. Often used for providing contrast for difficult to stain organisms like Treponema spp.

Dark field

Based on the medium recipe given below, identify whether the given medium is defined or undefined. Ingredients: Sucrose 10 grams, Cysteine 5 grams, Magnesium chloride 5 grams, Agar 5 grams, Distilled water 1000 ml

Defined

Because it is SO HOT in the summer time in Texas, you would be allowed to wear shorts and sandals when working in the lab during a summer course.

False

If your grade in the course is not what you had hoped for, never fear--there will be lots of extra credit work available to help bring up your average.

False

The final exam will NOT be cumulative and will only cover the material presented in the second half of the semester.

False

True or False: Staining a bacterial specimen with only crystal violet will allow you to visualize the size, shape, arrangement and Gram type of that bacterium.

False

When recording colony morphology, it is best to use Quadrant 1 as your source for colonies to describe.

False

PRCB test biochem process

Fermentation

Which is NOT a true statement about colony morphology?

One of the features that can be determined from examination of colony morphology is the shape of an organism as either a rod or cocci.

This type of light microscopy utilizes ultraviolet light and fluorescent dye. Often used to illuminate specific structures on a specimen.

Fluorescent

MRVP test substrate

Glucose

Lipopolysaccharide (LPS) outer membrane. G- or G+

Gram negative

The decolorizer extracts lipids from these cells making them lose crystal violet. G- or G+

Gram negative

These cells stain red/pink after all steps of proper Gram staining. G- or G+

Gram negative

Very thin peptidoglycan (PDG) inner layer. G- or G+

Gram negative

Gram's iodine helps these cells retain crystal violet in proper Gram staining. G- or G+

Gram positive

The decolorizer dehydrates these cells making crystal violet bind more intensely. G- or G+

Gram positive

These cells stain blue/purple after all steps of proper Gram staining. G- or G+

Gram positive

Thick, cross linked peptidoglycan (PDG) outer layer. G- or G+

Gram positive

After a successful Gram stain, you observe blue/purple, rod shaped cells arranged in long chains. The full, correct morphological description of these bacteria would be (include Gram stain, shape and arrangement):

Gram positive streptobacilli

This substance has the same refractive index as glass and is used to prevent the loss of light rays by directing them into the objective lens. Used only on the 100X objective.

Immersion oil

Indicate which PPE (Personal Protective Equipment) would be required to be worn while carrying out any experiment in the Micro lab. Select all that apply.

Lab coat: knee length and fully buttoned up Latex gloves (or other gloves made from hypoallergenic material) losed toe shoes that completely encompass the feet Long pants that completely cover the ankles Safety glasses All are required

What is the general purpose of streak plating a mixed culture?

Isolation into pure cultures/colonies

Used gloves are always considered contaminated and should be thrown away in the _____________________________.

Large Biohazard bin

Where should hazardous items like petri plate bacterial cultures be discarded?

Large biohazard bins

The term for the measurement of how far apart two points or details can be for them to be distinguished as separate

Limit of resolution

Why do we add 0.1% agar to our tryptic nitrate broth for the nitrate reduction test?

Limits diffusion of oxygen for anaerobic nitrate reduction

A nitrate reduction test has remained colorless after adding reagents A and B. Zinc is then added and the tube is still colorless. This is considered:

Long reduction

MR test reagent

Methyl red

MR test process

Mixed acid fermentation

The cytological basis for the acid-fast stain is the presence of _______________ in the cell walls.

Mycolic acid

Which of the following statements regarding the nitrate test are true? Please indicate all that apply.

Nitrate is reduced to nitrite via the simple pathway. After A plus B plus zinc, a colorless observation means long reduction has occurred. Nitrate reductase is the enzyme involved in the simple reduction pathway.

Nitrate simple test enzyme

Nitrate reductase

Nitrate reduction test simple pathway EPI

Nitrite

Matching: Hemolysis on blood agar Gamma hemolysis

No hemolysis observed

A nitrate reduction test is colorless after adding reagents A and B. Zinc is then added to the tube and the broth turns red. This is considered:

No reduction

The measure of how well a lens can capture light.

Numerical aperture

A bacteria species inoculated into fluid thioglycollate broth and incubated for 24 hours displays growth towards the very top of the tube where the resazurin indicator is pink. What aerotolerance category does this organism belong to? What growth pattern in broth best describes this type of growth?

Obligate or strictly aerobe/pellicle

A bacteria species inoculated into fluid thioglycollate broth and incubated for 24 hours displays growth towards the very bottom of the tube where the resazurin indicator is colorless. What aerotolerance category does this organism belong to? What growth pattern in broth best describes this type of growth?

Obligate or strictly anaerobe/sediment

An object in focus will remain in focus when switching objectives. This is a feature of our light microscopes....

Parfocal

Matching: Hemolysis on blood agar Alpha hemolysis

Partial breakdown of RBCs, greenish tint

Basic stains always have a ______________ charge.

Positive

Nitrate test substrate

Potassium nitrate

A nitrate reduction test has turned red after adding reagents A and B. This is considered:

Simple reduction

List the 7 characteristics you would use to describe colony morphology for an isolated colony you viewed from an observation image using a stereoscope, and give an example of a description you observed for each category when evaluating one of your 4 quadrant streak plates observation images.

Size ex: Punctiform Shape ex: Round Pigment ex: Orange Opacity ex: Translucent Texture ex: Mucoid Margin ex: serrated Elevation ex: Flat

The substrate that serves as the sole source of carbon in a Simmon's citrate test is:

Sodium citrate

The type of media that contains 1-2% agar is a:

Solid

Where would hazardous items like bacterial tube cultures be discarded?

Stainless steel racks on the sink at the discard area

The SIM medium is a combination medium that is used for the determination of the following bacterial activities:

Sulfur reduction, indole production and motility

A SIM biochemical test was inoculated and incubated for 24 hours at body temp. You observe a black precipitate in the stab line, and after adding Kovac's reagent, a yellow ring. What are your conclusions?

Sulfur reduction, non-motile, indole was not produced

Plasmodium, female Anopheles mosquito, Malaria, chloroquine.

The Apicomplexan organism seen here,________________ , is an intracellular parasite delivered to the human bloodstream via the insect vector,______________________ . The infection causes chills, fever, vomiting, and headaches in a cyclical fashion. This disease is known as_______________ and is common in sub saharan Africa. It is treated with____________________________ .

Exams will be offered online through Blackboard Learn and using Proctorio. Internet access, access to a computer and to a camera and microphone will be required for exam administration.

True

Trypanosoma cruzi, Chagas, Kissing bug

The protozoan parasite seen here is________ . This parasite causes the disease called______________ and is transmitted via the bite and feces deposition from the _______________. (vector)

A student is making a simple and basic stain. They aseptically apply broth culture to the slide, allow it to air dry, apply stain for 1 min, rinse with water and view using the 100X objective with immersion oil. They cannot seem to locate any stained cells on the slide. Where did they make a mistake?

They did not Heat fix the sample. This step adheres the bacteria to the slide. They probably washed off the bacteria when they rinsed with water.

A negative stain has a negative charge and stains the background instead of the cell itself.

True

Saccharomyces yeast cells

What organism and form is seen here?

Penicillim, conidia

What organism and structure is seen here? same pic but pink in notes

Clonorchis sinensis, Trematoda

What parasite is seen here in both the adult and egg form? What phylum/subphylum does it belong to? Trematoda, Cestoda (Flatworms) or a Nematode (roundworm)?

Why is the eradication of Malaria proving to be such a difficult task? (Please read your choices carefully.)

a. Complex life cycle and ecology of the parasite b. challenges of providing adequate medical care in the developing world c. desensitization leading to less precautions taken A, B, C are all correct

Select all the characteristics that apply to the Kingdom Protista (Protozoa).

a. Lack a cell wall c. Typically possess a mode of locomotion (motiliity) e. heterotrophic g. eukaryotic h. primarily asexual reproduction

Select all the characteristics that apply to the Kingdom Fungi.

a. Eukaryotic e.can be dimorphic f.heterotophic i.cell wall largely composed of chitin j.some produce antibiotics

A technique that is free of microbial contamination is called ____________________ technique.

aseptic

A microorganism that needs many ready-made organic compounds to survive is called a __________________ organism.

fastidious

PRCB test indicator

phenol red

A bacterial culture that contains a single species of bacteria is called a ____________________ culture.

pure

Nitrate reduction test reagents

sulfanilic acid, alpha naphthylamine, zinc

You are new to Micro lab and have just accidentally spilled bacterial culture directly onto your hands. Since you have diligently read and studied your lab safety handout, you know exactly how to handle this. What should you do?

wash the affected area twice with antimicrobial soap, rinsing with 70% ethanol (70% EtOH) between washings.