lab practical micro

In a serial dilution, the final dilution factor performed was 1:100,000. After 48 hours incubation @ 37oC there were 190 colonies counted on the plate. What was the concentration of bacteria in the original undiluted sample?

19,000,000 cfu/mL

How many phases are involved in the bacterial transformation process?

3

In this image of the objective lenses on a compound light microscope the lens on the far left would allow you to view a specimen at?

400X

In order to be classified as an insect, the organism should have_________ legs?

6

listeria

About 260 people die each year as a result of infection by this

listeria

An estimated 1,600 people get sick with this each year

Typical "normal" flora of the human body does not include which of the following?

Arthropods, helminths

gamma hemolysis

Bacteria is growing on the agar but there is no change in the appearance or color of the blood agar and no lysis of red blood cells

salmonella

Causes well over 1 million illnesses each year

salmonella

Causes ~23,000 hospitalizations each year due to infected food

Kingdom Plantae

Complex, multi-cellular organisms that use photosynthesis to make food.

kingdom fungi

Consists of unicellular and multicellular organisms that cannot make their own food (heterotrophs)

Kingdom Protista

Contain one celled eukaryotes such as algae and protozoa.

Differential media is a type of specialty media which?

Contain specific dyes that cause a color change as different bacteria grow and produce waste products.

What is known as the differential step in the Gram's stain procedure and why?

Decolorizer is the differential step because it is during this step that the gram negative bacteria will lose the purple color from the crystal violet stain.

Trichomonas vaginalis belongs to _____________ and _____________

Domain Eukarya, Kingdom Protista

What is the stain which can help visualize the structure formed by bacteria during unfavorable conditions that contains DNA and a small amount of cytoplasm encased by a protective outer covering which can then germinate during favorable conditions.

Endospore stain

What do bacteria form that may help them during unfavorable conditions such as heat, exposure to chemicals or radiation that allows them to remain metabolically inactive for many years and return to a vegetative form?

Endospores

Which of the following is the most lethal form of fungal disease?

Fungal Pneumonia

The new GHS system provides information on the labels of the chemicals that you will use in lab. What does GHS stand for?

Global Harmonized System

An agent or infection that began somewhere as an outbreak then became an epidemic which turned pandemic and is now endemic to the United States is?

Human Immunodeficiency virus

A hemoflagellate, such as Trypanosoma, is an organism that would be most likely be found?

In the bloodstream, but move outside of red blood cells by means of flagella

beta hemolysis

In this type of hemolysis a clear zone is left behind in the agar

What genus of tick is responsible for Lyme disease transmission in the United States?

Ixodes

kingdom bacteria

Kingdom of prokaryotic, single-celled organisms that lack a membrane-enclosed nucleus and can be classified by shape.

alpha hemolysis

Lysis of red blood cells occurs but the iron in the RBC is not consumed as a food source

Why should we be concerned with studying macroscopic parasites in a microbiology class and why would this be important to a clinical microbiologist?

Macroscopic organisms are sometimes vectors which deliver the causative agents of infections and it is important for clinical microbiologists to identify these pathways of agent transmission.

This disease is caused by a parasitic protozoan, which is transmitted through the bite of a Mosquito vector and delivered into the bloodstream of a definitive host.

Malaria

Mold cultures grow?

Much slower than bacterial cultures

difference between the "Spread Plate Method" and the "Streak Plate Method of Isolation" is___________ and one similarity is_________?

One difference between the two techniques is that the "Spread Plate Method " is used to evenly distribute the bacteria across the entire plate and a similarity is the end result should produce pure colonies in both methods.

It is important to note that Gram-positivity (the ability to retain the purple crystal violet-iodine complex) is not an all-or-nothing phenomenon but a matter of degree. There are several factors that could result in a Gram-positive organism staining Gram-negatively. Check all the factors that could apply to this situation.

Over decolorization, Overheating during heat fixation, The age of the culture

What is the component of the bacterial cell wall that is actually being stained?

Peptidoglycan layer

alpha hemolysis

The appearnce of a greenish color with bacterial growth on blood agar

After 48 hours of incubation at 37oC you observe a red color in the Methyl Red media after adding 6 drops of the proper reagent. This means that_____________?

The bacteria are positive for the production of an acid

Correctly define the term "definitive host".

The host in which the parasite spends its final development stage and reaches its mature form capable of reproduction.

When talking about microscopy in this laboratory parcentric means?

The specimen should stay mostly in the center of the field of view when switching between objective lenses.

What does the term pleomorphic mean concerning bacteria?

These bacteria have no consistent shape or size

When performing a serial dilution, a student forgot to change the pipette and used the same pipette for every .5 mL transfer of the solution from tube to tube. Would these results be accurate and what would you predict the outcome would be?

These results would be inaccurate because the extra culture on the inside and outside of the pipette would increase the concentration of the next tube beyond the factored amount.

beta hemolysis

This is the complete lysis of red blood cells on blood agar where all of the contents of the cell were consumed as a nutritional source

After performing a serial dilution a student counted 9 colonies on the 1:100,000 plate and 21 colonies on the 1:10,000 plate. Was this an accurate serial dilution? Why or why not?

This was not an accurate serial dilution because the number of colonies counted on the 1:100,000 plate was not within the target window and the difference in the count between the two plates was not close to a factor of 10.

The acid-fast stain is probably the second most frequently used stain. The acid-fast stain aids in diagnosis of what two diseases?

Tuberculosis and Leprosy

how or why aseptic technique would be used in a laboratory.

Using proper aseptic technique can greatly minimize or even eliminate the risk of contamination. Aseptic technique prevents microbes used in the laboratory from accidentally being released into the environment and/ or infecting people working in the laboratory. Proper aseptic technique prevents contamination of cultures from foreign bacteria inherent in the environment.

Which of the below is the correct procedure for washing your hands?

Wet your hands, apply soap, rub hands together while singing Happy Birthday twice, rinse well and dry, use the paper towel to turn off the faucet.

What does the yellow color of a sugar test tube indicate?

What does the yellow color of a sugar test tube indicate?

Which of the following is NOT a requirement for laboratory clothing?

You must wear a long sleeve shirt or blouse under your lab coat when in the lab.

A bacteria that will grow well in the environment of a refrigerator at a temperature of ~4oC could be best classified as?

a psycrophile

epidemic

a sudden and simultaneous outbreak or increase in the number of cases of disease in a community

What type of staining needs to be done on sputum cultures to identify the presence of Mycobacterium?

acid fast stain

facultative

adapt to variations in levels of oxygen

The process of fermentation includes the production of any or all of these waste products during bacterial metabolism.

alcohol, CO2, acid

Metal inoculating loops and needles are sterilized before and after use in a desktop incinerator to prevent introduction of unwanted organisms. Agar plates are held in a manner that minimizes the exposure of the surface to the environment. These are common practices that are observed while using proper_______________.

antiseptic technique

anaerobe

any organism that is able to live without oxygen

A fundemental technique important in the laboratory and used by Microbiologists for a variety of procedures such as, transferring cultures, inoculating media and isolation of pure cultures is known as?

aseptic technique

The type of inoculation technique used in this lab exercise, when transferring the environmental sample to the agar plate, is known as____________?

bacterial lawn

A positive reaction for Citrate agar will appear as?

blue

Locomotion by protists can be accomplished by which of the following means

cilia, Axostyle, flagella, Pseudopodium

During what form of horizontal gene transfer can plasmid DNA be replicated and passed to another bacterial cell?

conjugation

Kingdom Animalia

contain organisms that are multicellular eukaryotes including vertebrates and invertebrates.

pandemic

disease afflicting an increased proportion of population over wide geographic area

morbidity

diseased condition

aerotolerant

doesn't use oxygen but not harmed by it

All plasmids exist as______________and contain______________?

double stranded DNA; specialized genes

A yeast cell is?

eukaryotic, much larger than a bacterial cell, reproduces by budding, single-celled organism

types of data health officials collect during a foodborne outbreak investigation

food and environment data, epidemiological data, traceback data

These are projections on mold that function for nutrient uptake, adherence to substrate, and hold up reproductive structures.

hyphae

Clinically, most molds are identified by?

hyphae structure, appearance of the mycelium, asexual spore structure

The purpose of transferring the cultures into varying temperatures of hot and cold in order to make them permeable to extracellular DNA is known as?

inducing competency

aerobe

lives and grows in presence of oxygen

outbreak

localized occurrence of disease or illness within specific time period usually presumed to have common cause

E. coli

most strains of this are actually part of a healthy human instestinal tract

obligate aerobe

must have oxygen in order to grow

endemic

native disease that prevails continuously in geographic region

In which type of specialty stain is the background stained and the bacteria left unstained?

negative stain

incidence

number of new cases of disease occurring during given period

Mortality rate

number of people who have died as result of particular cause or due to all causes

While bacterial chromosomes normally carry all the genes necessary for growth and reproduction, bacteria also contain genes associated with extra-chromosomal DNA called?

plasmid

The acronym for the use of a fire extinguisher is PASS what does it stand for?

pull, aim, squeeze, sweep

The main phases of transformation in our experiment are?

recovery, growth, transformation

microaerophile

requires oxygen at levels below normal atmosphere

A method used to dilute a substance in a stepwise manner into a solution with a constant dilution factor is known as?

serial dilution

A zygospore would be considered a?

sexual spore

The mold Rhizopus consists of which of the following?

sexual spores, asexual spores, non-septate hyphae

mortality

the permanent and irreversible cessation of all vital functions

How can we know if this transformation experiment (or any experiment) is a valid test?

there should be both a positive and negative control

According to taxonomy of living organisms yeast and mold both belong to the the Kingdom Fungi.

true

An epidemiologist is responsible for tracking the movement, frequency and distribution of infectious disease transmitted throughout a population.

true

Contaminated food is often not the last food a person ate

true

When disposing of the environmental sample plates from this laboratory procedure they are to be considered a bio-hazard because they have been given nutrition, optimum temperature and time to grow. Allowing for more growth than would be found in nature.

true

Yeast can convert carbohydrates to carbon dioxide and alcohols in the respiratory process known as fermentation.

true

At what "total magnification" should you view your gram stained slide, as well as allbacterial slides?

1000x (oil immersion)

When you viewed the prepared slide of Staphylococcus in this lab exercise the appropriate objective lens to use would have been the?

100X

MacConkey agar (MAC) is most commonly used for the selective isolation of (a.)_____________ and differentiate them based on (b.)____________ resulting in a color change.

. Lactose fermentation Gram negative species

If you were viewing a bacterial slide using immersion oil you are at what magnification?

1000X

What are 3 ways you can help play a role in the network of organizations that investigate foodborne illness when you are sick?

Report your illness to your county health department, Ask your health care provider to order a stool or blood test to confirm foodborne illness, Make a food diary

List 4 protocols that must be followed for the collection of a biological specimen in order to obtain a timely and valid laboratory result.

Samples must be collected using proper collection techniques. It must be collected in the presence of the patient and labeled with 2 identifiers (such as patient name and number). Collected samples must be transported to the laboratory as soon as possible. It must be collected in the proper container.

An agar that contains a dye and/or indicator and a growth inhibitor as part of its ingredients can best be described as.

Selective and Differential

E. coli

Some strains can produce shiga-toxin or verocytotoxin

Lactose, maltose, mannitol, sucrose, and trehalose are all different types of___________ and they are all used under the general heading of____________ testing.

Sugars, carbohydrate