Term
| What is the purpose of using Phenol Red Broth |
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Definition
| Differentiates Enterobacteriaceae. Tests for carbohydrate fermentation and gas production. |
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Term
| How to determine carbohydrate fermentation in Phenol Red Broth |
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Definition
uninoculated = red (from Phenol Red pH indicator)
(+) for fermentation = yellow
(-) for fermentation = red |
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Term
| How to determine gas production in Phenol Red Broth |
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Definition
Gas in durham tube = (+) for gas production
No gas in durham tube = (-) for gas production |
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Term
| How to read TSI slant results |
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Definition
Acidic (A) = yellow
Alkaline (K) = red
Results are read Slant/Butt (ex. K/A = Alkaline slant and acidic butt) |
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Term
| How to determine number of sugars fermented in TSI |
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Definition
Glucose-only fermenters will be K/A (one sugar fermented)
Glucose, lactose &/OR sucrose will be A/A (at least two sugars fermented)
Non-fermenters will be K/K (no sugars fermented) |
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Term
| How to determine gas production in TSI |
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Definition
Agar lifts form bottom of tube
Fissure or crack forms in the agar
Bubble visible in the agar |
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Term
| How to determine H2S production in TSI |
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Definition
H2S indicator = ferrous sulfate
Black precipitate = positive reaction
A positive reaction requires acidic conditions, so if you only see black, it MUST BE acidic (ex. K/Black = K/A H2S (+) |
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Term
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Definition
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Term
| Gram reaction of organisms differentiated by TSI |
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Definition
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Term
| Family of organisms differentiated by TSI |
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Definition
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Term
| Organisms Bile Esculin Agar differntiates |
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Definition
| Inhibits Gram-positive except for Group D Streptococcus, including Enterococcus |
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Term
| What are the selective and differential agents in Bile Esculin Agar |
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Definition
selective = bile
differential = Esculin
Indicator = Ferric Citrate |
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Term
| How to read Bile Esculin media |
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Definition
| Black precipitate forms if the organism is Bile Esculin-positive. An organism that doesn't darken the media, is negative. |
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Term
| Two main families are differentiated in O-F tubes |
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Definition
| Differentiates Enterobacteriaceae from Pseudomonadaceae |
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Term
| Number of tubes used in O-F test |
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Definition
2 tubes
Oxidative tube - no mineral oil added
Fermentative tube - mineral oil added |
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Term
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Definition
pH indicator - Bromthymol Blue
Yellow = acidic pH
Green = neutral pH
(See slide #15 in PowerPoint #6 for further clarity) |
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Term
| Tests involved in SIM media |
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Definition
Sulfur reduction - H2S reacts with ferrous sulfate for form black precipitate = positive
Indole production - Add Kovac's reagent, if you see red = positive
Motility - Growth radiating away from stab line = positive
(See slide #17 on PowerPoint #6 for further clarity) |
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Term
| Family of organisms differentiated by SIM |
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Definition
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Term
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Definition
| Minimum Inhibitory Concentration - Minimum amount of antibiotic/disinfectant needed to inhibit bacterial growth |
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Term
| How to determine MIC from dilution procedure |
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Definition
1) The antibiotic/disinfectant is serially diluted
2) A standard amount of bacteria is added to each tube (i.e. 100ul)
3) Tubes are incubated overnight and then examined for lack of growth (no turbidity) the following day
4) To find the MIC, look for the greatest dilution with no turbidity |
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Term
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Definition
| Minimum Bactericidal Concentration - Minimum amount of antibiotic/disinfectant needed to kill or eliminate all bacteria |
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Term
| How to determine MBC from dilution procedure |
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Definition
| To find the MBC, subculture non-turbid tubes from the MIC test, and find the greatest dilution with no growth on the plate |
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Term
| Name of the antibiotic sensitivity method |
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Definition
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Term
| Media used for Kirby-Bauer Assay (and standards) |
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Definition
| Mueller-Hinton Agar (4mm thickness; pH 7.2-7.4) |
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Term
| Incubation time and temperature for Kirby-Bauer Assay |
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Definition
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Term
| McFarland standard and its purpose |
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Definition
| 0.5 McFarland turbidity standard is ~1.5 x 108 cells per ML standard used to match the turbidity of bacterial saline culture for MIC/MBC testing |
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Term
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Definition
Area devoid of growth around a disc
The zone is measured in mm and compared to reference ranges (Know how to read a table of antibiotic sensitivity standards as well) |
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Term
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Definition
To not be gross
Also, It's the most effective means of controlling spread of bacteria and nosocomial infections |
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Term
| Group of organisms eliminated by proper hand washing technique |
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Definition
| Transient microbes - organisms picked up in our daily activities |
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Term
| Top 3 organisms responsible for nosocomial infections |
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Definition
E. coli
S. aureus
P. aeruginosa |
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Term
| Know the process of determining an unknown organism and the media that could be used. |
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Definition
| You're on your own with this one. |
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Term
| Purpose of Rapid Strep Test |
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Definition
| These tests can be performed in the clinic (or at home) for point-of-care diagnosis and treatment (Also known as lateral flow assays) |
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Term
| Organism Rapid Strep Test detects |
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Definition
| Group A Streptococcus (specifically, Streptococcus pyogenes) |
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Term
| Purpose of using Enteropluri tubes and organisms detected |
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Definition
| 18-24 hour identification of Enterobacteriacae and other Gram negative, oxidase negative bacteria from non-clinical specimens |
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Term
| How to inoculate, complete tests, and read results for Enteropluri tubes |
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Definition
Includes 12 distinct chambers
Requires a pure culture of the organism to be tested
The test contains a needle that is used to pick up a colony, then is pulled through to inoculate all tests
The test is incubated at 37°C
After incubation the results are recorded and a numeric code is assigned based on a score sheet
The code is entered into a database to identify the unknown organism |
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Term
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Definition
| A virus that infects bacteria. Usually specific "phages" infect specific stains or species of bacteria (ex. Coliphages infect E. coli) |
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Term
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Definition
| A virus that infects E. coli |
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Term
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Definition
| Clear area on a bacterial lawn produced when phage infect and lyse bacterial cells |
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Term
| How to determine page specificity to a bacterial culture |
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Definition
Streak each organism onto a TSA plate utilizing the method used for the UV experiment
Apply 10μL of phage to each quadrant
Plates will be incubated @ 37°C
Examine results for phage specificity |
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Term
| Two major reasons scientists classify viruses as non-living |
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Definition
| Viruses are not cellular and they have no metabolism |
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Term
| Purpose of DNA extraction |
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Definition
| To obtain DNA in a relatively purified form, so it can then be used for further investigations (e.g. PCR, sequencing, electrophoresis, etc.) |
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Term
| Materials required to perform DNA extraction |
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Definition
Detergent (for lysing)
Table salt (for dissolving proteins)
Ice-cold ethanol (for precipitating DNA)
Stick (for spooling DNA for collection) |
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Term
| Know the steps and purpose of each step in the DNA extraction procedure |
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Definition
1) Add 10 ml DNA Extraction Buffer (soapy salty water) to squished strawberries and squish for a few more minutes. (Cell lysing and removal of protein contamination)
2) Filter through a moistened paper towel set in a funnel, and collect the liquid in a clear tube.
3) Add 2 volumes ice cold ethanol alcohol to the strawberry liquid in the tube. Pour the ethanol alcohol carefully down the side of the tube so that it forms a separate layer on top of the strawberry liquid. (DNA precipitation)
4) Watch for a few seconds. You should see a white fluffy cloud at the interface between the two liquids. That’s DNA!
5) Spin and stir the coffee stirrer in the tangle of DNA, wrapping the DNA around the stirrer. |
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Term
| Purpose of Polymerase Chain Reaction (PCR) |
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Definition
| Series of enzymatic reactions used to amplify (copy) small pieces of DNA |
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Term
| Basic materials needed to perform a PCR |
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Definition
Reaction components aka "master mix" include:
Sterile water
Appropriate buffer
Salts (MgCl2)
Nucelotides (dNTPs)
Primers (designed for target region)
Polymerase (Taq)
TEMPLATE DNA |
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Term
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Definition
| The bacterium Thermus aquaticus |
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Term
| Piece of equipment used to perform a PCR reaction |
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Definition
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Term
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Definition
Denaturing stage ~94°C - Separate template DNA
Annealing stage ~54°C - Primers bind to target sequences
Extension stage ~72°C - Complimentary DNA strand is synthesized using DNA polymerase and free dNTPs
Repeat for 30-40 cycles
Analyze PCR products using electrophoresis |
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Term
| Purpose of gel electrophoresis |
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Definition
| Separate DNA pieces out by size |
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Term
| Basic materials needed for gel electrophoresis |
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Definition
Electric current
Agarose or polyacrylamide gel
Stains such as Ethidium Bromide or SyBr Gold (to visualize DNA in the gel)
A base pair ladder (size ladder) to compare and identify correctly sized fragments |
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Term
| Aspects of the Gram-stain procedure |
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Definition
1) Flood slide with crystal violet (primary stain)
2) Flood slide with Gram's iodine (mordant)
3) Decolorize with acetone a few seconds
4) Flood slide with Safranin (secondary stain)
(*Rinse with water following each step*) |
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Term
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Definition
Used for Gram-positive organisms
Identifies organisms that produce the enzyme catalase
Differentiates families of Gram positive cocci
-Catalase (+) Micrococcaceae from
-Catalase (-) Streptococcaceae
Substrate: hydrogen peroxide
(+) test: bubbles form immediately
(-) test: no bubbles |
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Term
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Definition
| Used for Gram-negative organisms |
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Term
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Definition
Sometimes include trophozoite and/or cyst stages along with other forms.
Cyst - dormant, survival stage. May be infective form and/or helpful in diagnosis.
Trophozoite - Vegetative or actively growing form. |
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Term
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Definition
| Organism that carries and transmits pathogen |
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Term
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Definition
| Organism that harbors pathogen May be required to complete a particular part of organism’s life cycle and/or spread the organism May show signs of disease |
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Term
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Definition
Balantidium coli
Contracted via fecal-oral route
Animal reservoir - pig
Disease - Balantidiasis |
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Term
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Definition
Entamoeba histolytica
Contracted via fecal-oral route
Disease - amoebic dysentery |
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Term
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Definition
Giardia lamblia
Contracted via fecal-oral route
Disease - Giardiasis |
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Term
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Definition
Trichomonas vaginalis
Contracted via sexual contact
Disease - Trichomoniasis |
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Term
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Definition
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Term
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Definition
| Disease: African Sleeping Sickness (African trypanosomiasis) Vector: Tsetse Fly Location: Africa |
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Term
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Definition
| Disease: Chagas’Disease (American trypanosomiasis) Vector: Cone-nosed “Kissing” Bug Location: Central & South America |
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Term
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Definition
Plasmodium spp.
Disease - Malaria
Vector - Anopheles mosquito
Location - Africa, Asia, and South America
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Term
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Definition
Disease - Toxoplasmosis
Host - Cat |
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Term
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Definition
Cell wall usually composed of chitin
Informally divided into unicellular yeasts and filamentous molds
General purpose media high sugar, low pH (~5.6) (e.g. Sabouraud Dextrose Agar & Potato Dextrose Agar) |
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Term
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Definition
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Term
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Definition
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Term
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Definition
Rhizopus spp.
Disease - Zygomycosis |
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Term
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Definition
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Term
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Definition
Aspergillus spp.
Disease - Aspergillosis |
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Term
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Definition
| Round worms: roundworms with tapered ends |
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Term
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Definition
| Flukes: flat, leaf-like bodies |
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Term
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Definition
| Tapeworms: flatworms made of sections called proglottids with a scolex head |
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Term
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Definition
Enterobius vermicularis egg
Nematode
Human pinworm
Fecal-oral transmission or inhalation of the eggs |
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Term
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Definition
Enterobius vermicularis adult
Nematode
Human pinworm
Fecal-oral transmission or inhalation of the eggs |
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Term
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Definition
Trichinella spiralis
Nematode
Disease - Trichinosis
Usually comes form pork or game animals |
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Term
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Definition
Ascaris lumbricoides egg
Nematode
Most common helminthic infection
Female adult worms can reach length of 49 cm
Disease - Ascariasis |
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Term
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Definition
Necator/Ancylostoma egg
Nematode
Hookworms
Soil-transmitted
2nd most common helminthic infection
Necator americanus - worldwide; most common human-specifc hookworm
Ancylostoma duodenale - more geographically restricted
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Term
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Definition
Necator/Ancylostoma adult
Nematode
Hookworms
Soil-transmitted
2nd most common helminthic infection
Necator americanus - worldwide; most common human-specifc hookworm
Ancylostoma duodenale - more geographically restricted |
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Term
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Definition
Necator/Ancylostoma head
Nematode
Hookworms
Soil-transmitted
2nd most common helminthic infection
Necator americanus - worldwide; most common human-specifc hookworm
Ancylostoma duodenale - more geographically restricted |
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Term
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Definition
Fasciola hepatica
Trematode
Liver fluke
Disease - Fascioliasis
Host - herbivores, esp. sheep and cattle
Humans exposed when infective metacercariae residing on fresh water plants are ingested |
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Term
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Definition
Clonorchis sinensis
Trematode
Chinese liver fluke/Oriental liver fluke
Location - Asia
Disease - Clonorchiasis
Host - fish |
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Term
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Definition
Schistosoma spp. eggs (figure on left will be on the exam)
Trematode
Disease - Schistosomiasis
Intermediate host - snail |
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Term
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Definition
Schistosoma spp. adults (figure on left will be on the exam)
Trematode
Disease - Schistosomiasis
Intermediate host - snail |
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Term
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Definition
| Location: Brazil & Caribbean Adults reside in veins of the hepatic portal system |
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Term
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Definition
| Location: Africa & Middle East Adults reside in the veins associated with the urinary bladder |
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Term
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Definition
| Location: Southeast Asia Adults reside in the veins of the small intestines |
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Term
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Definition
Taenia solium egg
Cestode
Pork tapeworm
Disease - Taeniasis
Host - Pork |
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Term
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Definition
Taenia solium adult
Cestode
Pork tapeworm
Disease - Taeniasis
Host - Pork |
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