Term
The process of identifying an “unknown” bacterium is a rational and sequential procedure. What is the 1st step in attempting to identify the “unknown”? |
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Definition
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What is the 2nd step in identifying an unkown? |
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Definition
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Term
List 3 pieces of information that can be determined from a Gram stain |
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Definition
1. Gram reaction 2. Cell shape 3. cell arrangement |
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Term
list the 4 genus mentioned in the lab manual that are able to fix nitrogen |
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Definition
Rhizobium, Azobacter, Cyanobacteria, Clostridium |
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Term
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Definition
Living together in the same environment |
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Term
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Definition
organisms that live together in a particular environment |
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Term
name 2 enzymes that are involved in notrogen fixation |
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Definition
Nitrogenase and Transaminase |
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Term
name two end products of nitrogen fixation |
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Definition
Ammonia and Amino Acids(-> proteins) |
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Term
List 3 types of symbiotic relationships and describe each one |
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Definition
1. commensalism: the microbe benefits, the host is neither benefited or harmed 2. mutualism: the host and microbe both benefit each other 3. parasitism: the microbe benefits at the expense of the host |
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Term
Rhizobium and legume plants are an example of which type of symbiotic relationship? why? |
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Definition
Mutualism; because the Rhizobium cannot fix nitrogen without without a legume and it also obtains energy from carbohydrates synthesized by the plant, and the fixation gives the legume nitrogen that it can use for growth of plant parts |
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Term
what is the Gram reaction and cell shape of Rhizobium cells? |
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Definition
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Term
List 6 characteristcs of Staphylococci |
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Definition
1. Saprophytes and parasites of skin and mucus membranes 2. Gram-positive cocci arranged in clusters 3. Medium sized, off white or yellow colonies 4. faculative anaerobes 5. tolerant of high NaCl concentration 6. produces catalase |
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Term
Where are Staph found in the body? |
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Definition
skin and mucus membranes, especially nasopharynx and uppermost part of pharynx that is continuous with nasal passages |
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Term
Give one example of a pathogenic Staphylococcus |
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Definition
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Term
Give 2 examples of a Staph that is non-pathogenic |
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Definition
Staph epidermis and Staph saprophyticus |
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Term
what test can be used to differentiate between the pathogenic and non-pathogenic Staph? |
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Definition
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Term
List 4 diseases caused by Staph aureus |
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Definition
1. wound infections 2. pneumonia 3. toxic shock syndrome 4. food poisening |
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Term
List 7 characteristics of Streptococci |
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Definition
1. Saprophytes and parasites 2. Gram-positive coccie arragned in chains or pairs; small white colonies 3. More fastidious 4. faculative anaerobes 5. lactose fermenters 6. not catalse producers 7. no NaCl tolerance |
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Term
Streptococci are divided into 3 groups according to their type of hemolytic reaction. List and describe these groups |
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Definition
1. Alpha: hemolysins partially lyse red blood cells and reduce hemoglobin(red pigment) to methemoglobin(green pigment) 2. Beta: hemolysins completely lyse RBCs and decolorize the hemoglobin 3. Gamma: no lysis occurs |
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Term
3 characteristics of Hemolysins: |
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Definition
1. lyse RBCs 2. are produced by pathogenic bacteria 3. play a role in the virulence of the pathogenic organisms via aidning the infecting organism to escape some of the hosts productive mechanisms(such as blood clot formation) |
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Term
what is the function of the coagulase enzyme? |
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Definition
clots blood plasma without using thrombin |
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Term
How is the result of the mannitol fermentaion interpreted? |
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Definition
If mannitol is fermented, the agar turns from pink to yellow |
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Term
what is the correlation between the Mannitol Fermentation test and the Coagulase test? |
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Definition
if one is positive, the other one will be too |
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Term
Describe the Bile-Esculin test |
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Definition
Group D Strep can hydrolize bile-esculin into eculectin and glucose. Esculectin can be visualized by adding gerric citrate, which forms a black/grey complex |
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Term
Explain the principle of the NaCl tolerance test |
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Definition
Group D Strep arethe only group of strep resistant to Salt |
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Term
How is the NaCl tolerance test interpreted? |
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Definition
Positive result= turbidity in NaCl broth and/or deep purple color change to light purple |
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Term
List 7 characteristics of the enteric organisms |
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Definition
1. Gram (-) 2. faculative anaerobes 3. oxidase negative 4. catalse (+) 5. non-spore forming 6. ferment glucose 7. rod shaped |
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Term
What 2 diseases are caused by genus Escherichia? |
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Definition
Typhoid fever and acute gastro enteris |
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Term
which 3 genuses are frequently found in Urinary Tract infections but not GI tract? |
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Definition
Hafnia, Morgonella, Providencia |
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Term
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Definition
Gram-negative, non-spore forming, faculatively anaerobic rods that can ferment lactose |
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Term
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Definition
contains ingredients designed to elicit a specific biochemical of physiological response, allowing different groups to be differeintiated |
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Term
List 3 examples of differential media and what the differentiate |
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Definition
1. MacConkey Agar- lactose fementers 2. Bile Esculin Agar- Esculin hydrolysis 3. Mannitol Salt Agar- mannitol fermentation |
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Term
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Definition
contains components that inhibit growth of unwanted bacteria, thus selecting bacteria that are resistant to the components |
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Term
some media are both selective and differential, give 2 examples |
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Definition
MacConkey Agar and Mannitol Salt Agar |
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Term
TSI(Triple Sugar Iron) agar can detect: |
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Definition
1. glucose, sucrose, lactose fermentation 2. gas production 3. H2S production |
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Term
A yellow butt in the TSI agar indicates: |
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Definition
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Term
a yellow TSI slant indicates: |
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Definition
sucrose/ lactose fermentation |
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Term
IMVIC is a combination of which 4 tests? |
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Definition
Indole, Methyl-Red, Vogues-Proskauer, Inorganic Citrate |
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Term
The enterotube has 12 chambers and can perform how many tests simultaneously? |
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Definition
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Term
The enterotube can identify the level of... |
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Definition
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Term
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Definition
do not invade the tissues and cause damage, instead they reside on the surface |
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Term
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Definition
can cause disease of the host defenses are lowered of if the balance between bacteria and normal flora is disrupted |
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Term
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Definition
sometimes invade the body and cause disease of they can get past defenses |
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Term
What is the one weakness of the Kirby-Bauer Disc method? |
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Definition
it does not determine if an organism is bacteriostatic of bacteriocidal |
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Term
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Definition
inhibits growth but does not kill |
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Term
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Definition
inhibits growth and induces killing |
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Term
List the 9 factors that affect the size of inhibition zones |
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Definition
1. Sensitivity or organism 2. molecular size 3. concentration of agent 4. density of culture 5. rate of diffusion of agent 6. size of inoculum 7. time of incubation 8. temperature of incubation 9. interactions between agent and medium |
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Term
Name two antibiotics that are small in size |
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Definition
Pecicillin and ampicillin |
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Term
Name 2 antiobiotics that are large in size |
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Definition
Poolymyxin B and bacitracin |
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Term
MIC (minimal inhibitory concentration) |
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Definition
lowest concentration that prevents visible growth but not killing |
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Term
MBC (minimal bacteriocidal concentration) |
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Definition
lowest concentration that prevents visible growth and induces killing |
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Term
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Definition
lyses cells and is observed as a decrease in cell number or turbidity |
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Term
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Definition
the antimicrobial effect of two drugs used simultaneously is greater than tha of the drugs when used seperately |
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Term
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Definition
combination of two drugs interferes with each other's mechanisms and renders them ineffective |
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Term
Citrate Utilization
-how does the medium change and why? -what is the indicator? |
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Definition
Produce NH3(alkaline) --> Simon citrate slant medium changes green to blue due to a rise in pH. Bromothymol blue is the indicator |
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Term
How does Carbohydrate Fermentation and Gas Production in Durham tubes? What is the indicator? |
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Definition
the tube changes from green to yellow due to a drop in pH. BTB is the indicator |
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Term
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Definition
indole--> intermediate metabolite in breakdown of tryptophan(amino acid) -presence of enzyme tryptophase -Kovac's reagent--> reacts with indole-->red |
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Term
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Definition
tests for mix acids production from glucose fermentation. Turns red at pH below 4.4. Large acid: alcohol ratio. equal C02:H2 ratio. MR-VP medium-->add methyl red--> red is positive result. indicates the fermentation of glucose |
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Term
Vogue-Proskauer Test (Butanediol Fermentation) |
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Definition
also indicates fermentation of glucose to 2,3 butanediol and ethanol. detects the presence of acetoin. high alcohol:acid ratio. large amount of gas is produced, large C02:H2 ratio. MR-VP medium, add Barritts A and B--> wait for 20 minutes--> pink/red = positive |
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Term
3 Categories of Biological and Enzymatical Reactions Used to Identify Bacteria |
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Definition
1. Nutrient Requirements 2. Metabolic Intermediate or End Products 3. Presence of Specific Enzymes |
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Term
2 Tests Used to Determine the Nutrient requirements of a Bacterium |
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Definition
1. Citrate test 2. sugar fermentation test |
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Term
Citrate test -what does it determine? -what is the medium? -what is the indicator? -how are results interpreted? |
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Definition
-tests for the ability to use citrate as the sole source of carbon -Simon agar is used -Bromothymol Blue is the indicator -Change from green to blue (bc of pH increase) is a positive result |
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Term
Sugar Fermentation test -what does it determine? -what is the medium? -what is the indicator? -how are results interpreted? |
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Definition
-tests for Carbohydrate fermentation and gas production in a Durham tube -tube changes from green to yellow (+ result) due to decrease in pH -Bromothymol blue is the indicator -if gas is produced, it is shown by a trapped bubble |
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Term
3 Tests that Determine the Metabolic Products of an Organism |
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Definition
1. Indole test 2. Methyl Red test 3. Vogues-Proskauer test |
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Term
Indole Test -what does it test for? -what reagent is used? |
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Definition
-tests for the production of indole from tryptophan (an amino acid) Tryptophase breaks down tryptophan into indole, pyruvic acid, and ammonia. Indole is what is what is being tested for, but it implactes the presence of tryptophase -the presence of indole is seen by adding Kovac's reagent, which reacts with indole and creates a red complex |
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Term
Methyl Red test -what does it test for? what is the indicator? Medium? -how are results interpreted? |
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Definition
-tests for strong acid production from fermentation. Methyk red organisms produce large amounts of lactic, succinic, and acetic acid --> low pH. the produce small amount of ehtanol --> large acid:alcohol ratio -if an organism has formic hydrogenase, then equal amounts of CO2 and H2 are produced. -indicator methyl red turns red at or below pH 4.4 -MR-VP broth is used (a glucose broth) |
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Term
Vogues-Proskauer Test -what does it indicate? -what does it detect? -what medium is used? reagent? -how are the results interpreted? |
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Definition
-indicates fermentation of glucose to 2,3 butanediol and ethanol -detects presence fo acetoin -high alcohol: acid ratio -large amounts of gas produced, large CO2:H2 ratio - MR-VP medium used -add Barrits A and B --> wait 20 minutes --> pink/red= positive |
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Term
3 tests that indicate the presence of specific enzymes |
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Definition
1. Oxidase test 2. Catalase test 3. Urease test |
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Term
Oxidase test -what does it determine? -what dye is used? |
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Definition
-determines if organisms have Cytochrome C. Oxidase -use a colorless dy: p-phenylenediamine dihydrochloride as an artificial electron donor -->dye is oxidized--> blue/black color |
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Term
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Definition
-catalase converts hydrogen peroxide to oxygen and water -usually facultative aerobes and obligate aerobes have catalase -add H2O2, ifi t bubbles, catalase is present |
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Term
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Definition
-determine ability of organism to hydrolyze urea -urease converts urea broth into ammonia and CO2 -hot pink color (due to pH increase) indicates positive result |
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Term
Cysteine Desulfurase Test |
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Definition
-detection of H2S production -Kligler's iron agar (KIA) is used -dark precipitate indicates H2S production -if yellow |
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Term
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Definition
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Term
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Definition
nucleic acid and proteins- basic structure --> capsid or shell which encloses the nucleic acids (either DNA or RNA) |
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Term
2 major qualities of a virus |
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Definition
1. possesion of its own genetic material, which, on its own, behaves as part of the host cell 2. possesion of extracellular infective state, represented by specialized onjects, the virions, which are produced in the cell under genetic control of the virus itself and serve as vehicles for introducing the viral genome into other cells |
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Term
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Definition
a clear spot on a bacterial lawn that contains no bacteria bc all the cells have been lysed |
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Term
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Definition
-helical: spring shaped -polyhedral: many sided -binal: polyhedral head w/ helical tail(nucleic acid in head) |
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Term
3 types of T type coliphages |
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Definition
a. T even phages: similar in geneitc constitution and serologic properties -->pyrimidine, 5-hyroxymethylcytosine replaces cytosine b. T5: resembles T even phages except has regular cytosine c. T1, T3, T7: seroligically an genetically unrelated to both one another and the T-even phages |
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Term
5 Stages of phage infection |
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Definition
1. adsorption to specific receptor sites on bacterial cell 2. penetration of phage nucleic acid into bacterial host, protein coat remaining outside 3. intracellular development: phage replication, biosynthesis 4. maturation 5. lysis --> release |
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Term
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Definition
viral nucleic acid persists in host for many generations(or indefinitely). bacterial host functions normally, viral nucleic acid is transmitted successively through many bacterial generations |
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Term
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Definition
bacteriophages that cause lysogeny |
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Term
lysogens/ lysogenic strains |
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Definition
bacterial hosts of lysogeny |
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Term
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Definition
latent, non-infectious form which is carried in lysogenic bacteria |
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Term
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Definition
gram(-) rods symbiotic organism that invades root hairs nitrogen fixing |
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Term
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Definition
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Term
2 enzymesi nvolved in notrogen fixation |
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Definition
transaminase & nitrogenase |
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Term
2 final end products of Nitrogen fixation |
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Definition
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Term
whati s the shape and gram reaction of Staphylococci? |
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Definition
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Term
what is the arrangement and color of Staphylococci colonies? |
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Definition
golden/ off white clusters |
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Term
Is Staph tolerant of NaCl? |
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Definition
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Term
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Definition
skin follicles and mucus membranes |
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Term
Staph's oxygen requirement is... |
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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
Staph epidermidis and Staph saprophyticus |
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Term
what test is used to differentiate between pathogenic and non-pathogenic Staph? |
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Definition
coagulase test --> (+)test = pathogenic -->coagulase converts fibrinogen to fibrin and clots plasma |
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Term
S. aureus causes which diseases? |
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Definition
wound infections, pneumonia, toxic shock syndrome, food poisening |
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Term
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Definition
hospital acquired infections |
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Term
S. autotrophyticus causes... |
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Definition
urinary tract infections (UIT) |
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Term
what is the gram reaction and shape of Streptococci? |
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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
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Term
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Definition
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