Term
| Mannitol Salts Agar - Contains ____________ which inhibits growth of almost all bacteria except _______________ |
|
Definition
| sodium chloride, Staphylococcus |
|
|
Term
| Mannitol Salts Agar -- Only Staph. aureus can ferment ______________ |
|
Definition
|
|
Term
| Mannitol Salts Agar - _______________ is the pH indicator |
|
Definition
|
|
Term
| Mannitol Salts Agar - If mannitol is fermented, the phenol red turns _____________ due to the production of ____________ end products. |
|
Definition
|
|
Term
| Mannitol Salts Agar - Only Staph. ____________ will have a ___________ zone around its growth. |
|
Definition
|
|
Term
| Mannitol Salts Agar - The salt selects for __________________ species. |
|
Definition
|
|
Term
| Mannitol Salts Agar - The mannitol helps ___________ Staph. aureus from other Staph. species. |
|
Definition
|
|
Term
| Standard Plate Count - Used to estimate the number of organisms in a sample of _____________ |
|
Definition
|
|
Term
| Standard Plate Count - Dilutions are made to reduce the number of bacteria per volume of liquid to a number that can be _______________ |
|
Definition
|
|
Term
| Standard Plate Count - Define CFU |
|
Definition
|
|
Term
| Oxidation-Fermentation Test - Differentiates fermenters from _______________ |
|
Definition
|
|
Term
| Oxidation-Fermentation Test - OF media can contain one of many ___________. We use glucose. |
|
Definition
|
|
Term
| Oxidation-Fermentation Test - In oxidation, glucose is oxidized to _________ and then converted to ________ in the _____________ cycle and ________ ____________ ________. _________ is the final electron acceptor. This process will produce an ____________ environment. |
|
Definition
pyruvate
CO2
Krebs
electron transport chain
Oxygen
acidic |
|
|
Term
| Oxidation-Fermentation Test - In fermentation, glucose becomes _____________ and then is converted into an acid end product in the _____________ of oxygen. |
|
Definition
|
|
Term
| Oxidation-Fermentation Test - The pH indicator _____________ blue is green at pH 7.1 and ____________ below 6.0. |
|
Definition
|
|
Term
| Oxidation-Fermentation Test - __________ oil is used to create an ____________ environment where only ______________ can occur. |
|
Definition
| mineral, anaerobic, fermentation |
|
|
Term
| Oxidation-Fermentation Test - In the tubes without mineral oil, oxygen can diffuse into the top of the ________________ media producing an environment where ______________ can occur. |
|
Definition
|
|
Term
| Oxidation-Fermentation Test - Fermenters, or organisms that ferment and oxidize, produce acid and turn the media _______________ in __________ tubes. The tube with oil is anaerobic throughout. Fermentation is an anaerobic process. The tube without oil is anaerobic at the bottom and fermentation will occur here. The acid will affect the ___________ tube. |
|
Definition
|
|
Term
| Oxidation-Fermentation Test - Organisms that _______________ only will turn the aerobic area of the media (top) yellow only in the tube without mineral oil. |
|
Definition
|
|
Term
| Oxidation-Fermentation Test - Organisms that don't ferment or oxidize glucose will not make ____________. The tubes will be ________ (no change). The tubes may be __________ indicating that the organism produced alkaline end products from __________ acid utilization. |
|
Definition
|
|
Term
| MR/VP - The methyl red test (MR) is used to identify organisms that produce ____________ mixed-acid end products from _______________. |
|
Definition
|
|
Term
| MR/VP - Methyl red is added ____________ incubation to detect acid. It will turn red ___________ pH 4.4. |
|
Definition
|
|
Term
| MR/VP - The Voges Proskaur test is used to detect organism that produce ___________ acids from glucose fermentation. |
|
Definition
|
|
Term
| MR/VP - VP test - These unstable acids are readily converted into ____________ and 2,3 butanediol which __________ the pH. |
|
Definition
|
|
Term
| MR/VP - VP reagents will turn _________ in the presence of these alkaline end products. An organism cannot be MR and VP positive. It is one or the other. |
|
Definition
|
|
Term
| Starch Hydrolysis - Starch is made of chains of _________________ molecules. |
|
Definition
|
|
Term
| Starch Hydrolysis - Starch is too big to enter ____________ cells. |
|
Definition
|
|
Term
| Starch Hydrolysis - In order to use the glucose, the bacteria must first break the _____________ into glucose. |
|
Definition
|
|
Term
| Starch Hydrolysis - The enzymes bacteria use to do this are called __________________ and oligo-1,6-glucosidase. |
|
Definition
|
|
Term
| Starch Hydrolysis - These enzymes are _____________. That is, the cells secrete the enzymes into their environment. |
|
Definition
|
|
Term
| Starch Hydrolysis - If the starch has been digested by the bacteria, starch will not be present in the ________ surrounding the colonies. |
|
Definition
|
|
Term
| Starch Hydrolysis - Iodine turns blue or __________ in the presence of starch. |
|
Definition
|
|
Term
| Starch Hydrolysis - If the media surrounding a colony is ______________ after the addition of iodine, the bacteria have digested the _________________. |
|
Definition
|
|
Term
| Oxidase Test - There are many types of bacterial electron transport chains. One type uses the molecule _____________ __ ___________to transfer electrons to ___________. |
|
Definition
| cytochrome c oxidase, oxygen |
|
|
Term
| Oxidase Test - Most enterobacteriaceae are oxidase _________________. |
|
Definition
|
|
Term
| Oxidase Test - Most nonfermenters like _____________ are oxidase positive. |
|
Definition
|
|
Term
| Oxidase Test - Paper which is impregnated with tetramethyl-p-phenylenediamine can be ________________ by cytochrome c oxidase. |
|
Definition
|
|
Term
| Oxidase Test - When tetramethyl-p-phenylenediamine is oxidized by cytochrome c oxidase, it turns dark _______. This means the organism is oxidase positive and is probably not an enterobacteriaceae. |
|
Definition
|
|
Term
| API 20E - This system uses 20 tests simultaneously to identify bacteria. The 20E is used for enterobacteriaceae. Results are interpreted in groups of __________ to determine a code. The code is compared to a list of possible _____________. |
|
Definition
|
|
Term
| Catalase - In order to convert ADP to ATP, organisms use the _________ cycle and the _________ ________ _______. |
|
Definition
| Krebs, electron transport chain |
|
|
Term
| Catalase - One of the pathways in the electron transport chain produces hydrogen __________ (H2O2), and super oxide (O2) |
|
Definition
|
|
Term
| Catalase - H2O2 and O2 are __________ to cells. So they produce the enzyme superoxide ______________ that converts O2 into H2O2 and the enzyme ___________ which converts H2O2 into water and O2. The oxygen is released as a ________. |
|
Definition
toxic
dismutase
catalase
gas |
|
|
Term
| Catalase - When we add hydrogen peroxide to an organism that produces catalase, ________ will be produced. |
|
Definition
|
|
Term
| Nitrate Reduction Test - Anaerobic respiration involves the transfer of electrons to an inorganic molecule other than ________________. Nitrate is one of those molecules. |
|
Definition
|
|
Term
| Nitrate Reduction Test - Almost all enterobacteriaceae use the enzyme _________________ to reduce nitrate NO3 to ____________ NO2 |
|
Definition
| nitrate reductase, nitrite |
|
|
Term
| Nitrate Reduction Test - Other bacteria further reduce nitrite to nitrogen ____________ (N2). |
|
Definition
|
|
Term
| Thioglycollate Medium - This media has a ___________ of oxygen concentration, aerobic at the top, __________ at the bottom. |
|
Definition
|
|
Term
| Thioglycollate Medium - Sodium thioglycollate and ____________ in the media reduce oxygen to ______________. |
|
Definition
|
|
Term
| Thioglycollate Medium - Rezazurin in the media turns _________ when oxidized indicating that part of the media contains ____________. |
|
Definition
|
|
Term
| Thioglycollate Medium - A small amount of ___________ in the media _________ diffusion of oxygen. |
|
Definition
|
|
Term
| Anaerobic jar - Used to cultivate _________ and ____________. |
|
Definition
| anaerobes, microaerophiles |
|
|
Term
| Anaerobic jar - After the jar is sealed, a packet is added to ____________ the ____________. |
|
Definition
|
|
Term
| Anaerobic jar - Sodium borohydride and sodium ____________ reacted with water to form ____________ gas and ____________. |
|
Definition
| bicarbonate, hydrogen, CO2 |
|
|
Term
| Anaerobic jar - Oxygen and hydrogen form _________ in the presence of the __________ catalyst. |
|
Definition
|
|
Term
| Anaerobic jar - The indicator contains ____________ blue which is colorless when _______________ (anaerobic) and blue when in the presence of ______________. |
|
Definition
| methylene, reduced, oxygen |
|
|
Term
| The nitrate reduction test is based on the detection of ____________________ in the medium after incubation with an organism |
|
Definition
|
|
Term
| Nitrate reduction test - After adding nitrate A & B reagent, red indicates: |
|
Definition
|
|
Term
| Nitrate reduction test - After adding nitrate A & B reagent, yellow indicates: |
|
Definition
| that nitrite is not present in the medium and that zinc dust must be added to determine if the organism is nitrate negative or if the organism has reduced the nitrate to nitrite and then reduced to nitric oxide, nitrous oxide or nitrogen (will not react to nitrate reagents) |
|
|
Term
| Nitrate reduction test - After adding zinc dust, red indicates: |
|
Definition
| organism is nitrate negative |
|
|
Term
| Nitrate reduction test - After adding zinc dust, yellow indicates: |
|
Definition
| organism is nitrate positive and produced nitrite which was further reduced to NO, N2O, or N2. |
|
|
Term
|
Definition
| a series of controlled transfers down a line of dilution blanks (tubes containing a known volume of sterile dilutent). The series begins with a sample containing an unknown concentration of cells (density) and ends with a very diulte mixture containing only a few cells. |
|
|
Term
|
Definition
| one that contains between 30 and 300 colonies. A count lower than 30 is considered statistically unreliable (TFTC - too few to count) and greater than 300 is typically too many to be viewed as individual colonies (TMTC - too many to count). |
|
|
Term
| formula for Original Cell Density (OCD) |
|
Definition
CFU
OCD=----------------
D X V
|
|
|
Term
| If you innoculate a plate with 0.1 mL of a 10-5 dilution and counted 37 CFUs, what is the original density count? |
|
Definition
OCD = CFU/D x V
OCD = 37 CFU/ 10-5 x 0.1 mL
OCD = 37 CFU/10-6 mL
OCD = 37 x 106 CFU/mL
OCD = 3.7 x 107 CFU/mL |
|
|
Term
| If you innoculate a plate with 0.1 mL of a 10-7 dilution and counted 33 CFUs, what is the original density count? |
|
Definition
OCD = CFU/D x V
OCD = 33 CFU/ 10-7 x 0.1 mL
OCD = 33 CFU/10-8 mL
OCD = 33 x 108 CFU/mL
OCD = 3.3 x 109 CFU/mL |
|
|
Term
|
Definition
mL of sample
dilution = --------------------------------------
total volume |
|
|
Term
| What would be the dilution if 96 mL of dilutent is added to 4 mL of a bacterial suspension? |
|
Definition
dilution=mL of sample/total volume
dilution= 4 mL/96 mL + 4 mL
dilution = 4 mL/100 mL
dilution = 4/102
dilution = 4 x 10-2 |
|
|
Term
| If you add 1.0 mL of an undiluted sample to 99 mL of sterile dilutent, what is the dilution? |
|
Definition
dilution=mL of sample/total volume
dilution= 1 mL/99 mL + 1 mL
dilution = 1 mL/100 mL
dilution = 1/102
dilution = 1 x 10-2 |
|
|
Term
| If you add 5.0 mL of an undiluted sample to 99 mL of sterile dilutent, what is the dilution? |
|
Definition
dilution=mL of sample/total volume
dilution= 5 mL/99 mL + 5 mL
dilution = 5 mL/104 mL
dilution = 0.048
dilution = 4.8 x 10-2 |
|
|
Term
| The plate has 72 colonies, with a sample volume of 10-7 mL. What was the original concentration in the sample? |
|
Definition
OCD = CFU/sample volume
OCD = 72 CFU/10-7 mL
OCD = 72 x 107 CFU/mL
OCD = 7.2 x 108 CFU/mL |
|
|
Term
| The plate has 259 colonies, with a sample volume of 10-6 mL. What was the original concentration in the sample? |
|
Definition
OCD = CFU/sample volume
OCD = 259 CFU/10-6 mL
OCD = 259 x 106 CFU/mL
OCD = 2.59 x 108 CFU/mL |
|
|
Term
| How many colonies should be on the plate innoculated with a sample volume of 10-7 with an OCD of 2.59 x 108? |
|
Definition
OCD = CFU/sample volume
2.59 x 108 = x CFU/10-7 mL
(2.59 x 108)(10-7 mL) = (x CFU/10-7 mL)(10-7 mL)
2.59 x 101 CFU = x |
|
|
Term
| How many colonies should be on the plate innoculated with a sample volume of 10-5 with an OCD of 2.59 x 108? |
|
Definition
OCD = CFU/sample volume
2.59 x 108 = x CFU/10-5 mL
(2.59 x 108)(10-5mL) = (x CFU/10-5 mL)(10-5 mL)
2.59 x 103 CFU = x |
|
|
Term
| A plate inoculated with a sample volume of 10-7 mL produced 170 colonies. What was the orignial concentration? |
|
Definition
OCD = CFU/sample volume
OCD = 170 CFU/10-7 mL
OCD = 170 x 107 CFU/mL
OCD = 1.7 x 109 CFU/mL |
|
|
Term
| After incubation, how many colonies should be on the 10-8 mL plate from the dilution series with an OCD of 1.7 x 109? |
|
Definition
OCD = CFU/sample volume
1.7 x 109 = x CFU/10-8 mL
(1.7 x 109)(10-8 mL) = (x CFU/10-8 mL)(10-8 mL)
1.7 x 101 CFU = x |
|
|
Term
| After incubation, how many colonies should be on the 10-6 mL plate from the dilution series with an OCD of 1.7 x 109? |
|
Definition
OCD = CFU/sample volume
1.7 x 109 = x CFU/10-6 mL
(1.7 x 109)(10-6 mL) = (x CFU/10-6mL)(10-6 mL)
1.7 x 103 CFU = x |
|
|
Term
| You have inoculated 100 μL of a sample diluted by a factor of 10-3 on a plate. After incubation, you count 58 colonies. What was the original cell density? |
|
Definition
100 μL = 0.1 mL
OCD = CFU/D x V
OCD = 58 CFU/ 10-3 x 0.1 mL
OCD = 58 CFU/10-4 mL
OCD = 58 x 104 CFU/mL
OCD = 5.8 x 105 CFU/mL |
|
|
Term
| Results of E. coli on mannitol salt agar |
|
Definition
| no growth on MSA, can't grow in salt |
|
|
Term
| Results of Staph. aureus on mannitol salt agar |
|
Definition
| growth with yellow, tolerates salt |
|
|
Term
| Results of Staph. epi on mannitol salt agar |
|
Definition
| growth on MSA, but remains red, tolerates salt |
|
|
Term
| Mannitol Salts Agar Lab - What purpose does the Nutrient Agar plate serve? In what way does it increase the validity of the test result? |
|
Definition
| The Nutrient Agar plate acts as a control to see if each organism grows without the presence of salt. |
|
|
Term
| What would be the likely consequences of omitting the NaCl in Mannitol Salt Agar? Why? |
|
Definition
| The E. coli would grow and you could not select for the Staphylococcus. |
|
|
Term
| Would omitting the NaCl alter the Mannitol Salts Agar's specificity or sensitivity? |
|
Definition
| It would alter the medium's specificity because you could not select for the Staphylococcus. |
|
|
Term
|
Definition
|
|
Term
| O-F test - What is the purpose of the uninoculated control tubes used in this test? |
|
Definition
| Two uninoculated control tubes are needed to show the results of the medium in both aerobic and anaerobic environments. It is used to show that the medium remains green under both conditions, showing it is sterile and also as a color comparison. |
|
|
Term
| O-F test - What color results would you expect for organisms in O-F glucose media inoculated with an enteric? |
|
Definition
| Since enterics can both oxidize and ferment, both the unsealed (aerobic) tube and the sealed (anaerobic) tube will turn yellow. |
|
|
Term
| O-F test - results of Enterobacteriaceae, Pseudomonas, and Alcaligenes |
|
Definition
Enterobacteriaceae - sealed:yellow, unsealed:yellow - oxidation and fermentation
Pseudomonas - sealed:green, unsealed:yellow - oxidation
Alcaligenes - sealed:green, unsealed:green - non-reactive
|
|
|
Term
O-F Medium Results and Interpretation
[image] |
|
Definition
sealed:green or blue, unsealed:any yellow - oxidation
sealed:yellow, unsealed:yellow - oxidation and fermentation (or fermentation only)
sealed:green or blue, unsealed:green or blue - no sugar metabolism
blue indicates organism used peptone and produced alkaline end products |
|
|
Term
| MR-VP test - Detects organisms capable of performing _____________________ and produce _________ acids. |
|
Definition
mixed acid fermentation
stable |
|
|
Term
| MR-VP test - for MR test, a positive result is ______ and indicates a ______ pH. |
|
Definition
|
|
Term
| MR-VP test - VP test detects organisms that are able to ferment glucose, but convert their products to _____________ |
|
Definition
|
|
Term
| MR-VP test - VP test - a positive result is _________ and indicates a _________ pH |
|
Definition
|
|
Term
| MR-VP test - Which of the two tests would likely produce more false negatives with a shorter incubation time and why? |
|
Definition
| The VP test because VP positive organisms need time for the unstable acids to convert to acetoin |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Starch Hyrdolysis - Organisms that can break down starch contain the enzyme ___________ |
|
Definition
|
|
Term
| Starch Hydrolysis - A positive result is: |
|
Definition
| a clearing around growth, indicating amylase is present |
|
|
Term
| Starch hydrolysis - a negative result is: |
|
Definition
| no clearing around growth, no amylase present |
|
|
Term
| starch hydrolysis - in many tests it is acceptable to read a positive result before the incubation time is completed. why is this not the case with starch agar? |
|
Definition
| because if the enzyme amylase is present, it needs time to break the starch down to glucose |
|
|
Term
|
Definition
| starch hydrolysis - left negative result, right positive result |
|
|
Term
| catalse test - catalase test converts hydrogen peroxide into ____________ |
|
Definition
|
|
Term
| catalase test - positive result is: |
|
Definition
| bubbles, catalase is present |
|
|
Term
| catalase test - negative result |
|
Definition
| no bubbles, no catalase is present |
|
|
Term
| catalase test - why is it advisable to perform this test on a known catalase-positive organism along with the organism you are testing? |
|
Definition
| to make sure the hydrogen peroxide has not broken down and is still working |
|
|
Term
|
Definition
|
|
Term
| oxidase test - positive result is: |
|
Definition
| dark blue withing 20 seconds, cytochrome c oxidase is present |
|
|
Term
| oxidase test - negative result is: |
|
Definition
| no color change to blue within 20 seconds, cytochrome c oxidase is NOT present |
|
|
Term
|
Definition
|
|
Term
| API 20 E - why is it important to perform the reagent test last? |
|
Definition
| Because you need to look for spontaneous reactions first. Also, if you splash reagents into adjacent cups you could change their color |
|
|
Term
|
Definition
| how to read an API 20 E test |
|
|
Term
| Nitrate Reduction Test - after adding A & B reagents, a red result means: |
|
Definition
| nitrate-positive, nitrate reduction to nitrite (NO3 -> NO2) |
|
|
Term
| Nitrate reduction test - yellow result after adding A & B reagents indicates: |
|
Definition
incomplete test, zinc must be added
may be nitrate-negative
or may have further reduced nitrite to nitric oxide, nitrous oxide or nitrogen |
|
|
Term
| nitrate reduction test - after adding zinc dust, no color change indicates: |
|
Definition
| nitrate positive - nitrate reduction to NO, N2O, or N2 |
|
|
Term
| nitrate reduction test - after adding zinc dust, red color change indicates: |
|
Definition
| no nitrate reduction, nitrate-negative |
|
|
Term
|
Definition
|
|
Term
| fluid thioglycollate medium - good for cultivation of _____________ and ______________ |
|
Definition
| strict anaerobes, microaerophiles |
|
|
Term
| fluid thioglycollate medium - is ________ at the top and _____________ at the bottom |
|
Definition
|
|
Term
| fluid thioglycollate medium - the aerobic zone is _________ in color |
|
Definition
|
|
Term
fluid thioglycollate medium growth
[image] |
|
Definition
1 - aerobe - growth only at top
2 - faculative anaerobe - growth throughout, but more growth at top
3 - aerotolerant anaerobe - growth throughout tube
4 - anaerobe - no growth at top |
|
|
Term
|
Definition
| Brewer anaerobic jar, used to culture anaerobes |
|
|
