Term
The Gelatin Hydrolysis Test tests for what? |
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Definition
Presence of gelatinases that hydrolyze proteins found found in host connective tissue. (Collagen and Gelatin) |
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Term
The Gelatin Hydrolysis Test that consists of a liquid after culture of a bacterium indicates what? |
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Definition
The presence of gelatinases in the bacterium. |
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Term
What growth media is used for the Gelatin Hydrolysis Test? |
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Definition
Nutrient Gelatin - beef extract, peptone and gelatin |
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Term
Cultures of S. Aureus and E. Aeroginosa are incubated in a Nutrient Gelatin media. What will be the consistency of the test tube? |
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Definition
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Term
Of S. aureus, S. epidermidis, S. marcescans and E. aerogenosa, which media will be liquid after incubation in Nutrient Gelatin growth media? |
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Definition
S. aureus and S. marcescans |
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Term
What type of bacteria produce hemolysins? |
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Definition
Gram positive pathogenic bacteria |
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Term
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Definition
Exotoxins that damage RBCS |
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Term
What media is used for the hemolysis test? |
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Definition
Blood agar - Tryptic soy agar and 5% sheep blood |
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Term
What are three examples of hemolytic bacteria? |
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Definition
Staphylococcus, streptococcus and listeria |
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Term
The partial destruction of RBC's and a greenish discoloration in the media indicates the presence of what? |
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Definition
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Term
The complete destruction of RBC's and a clearing in the media indicates the presence of what? |
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Definition
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Term
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Definition
Produced by bacteria to degrade neutrophil DNA and break down NET's to escape phagocytosis |
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Term
What does the DNA Hydrolysis Test test for? |
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Definition
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Term
Clearing around bacterial colonies in a DNA Hydrolysis test indicates what? |
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Definition
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Term
A negative DNA Hydrolysis test will look like what? |
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Definition
The blue-green dye media without clearing |
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Term
What are the predominant causes of dental caries? |
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Definition
Lactobacillus and streptococcus |
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Term
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Definition
Fermentation of dietary sugars by microbes that lead to acid production that wear away tooth enamel and promote decay |
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Term
What does the Snyder test test for? |
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Definition
A persons' susceptibility to forming dental caries as a result of the presence of lactobacilli or streptococci |
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Term
How does the Snyder test select for lactobacilli? |
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Definition
The pH is reduced to 4.8 - the bacteria are acid-tolerant |
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Term
A media that changes green to yellow in the Snyder test indicates what? |
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Definition
The presence of lactobacilli or streptococci. |
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Term
A change in color after 24 hours indicates what in the snyder test? |
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Definition
A high susceptibility to dental caries |
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Term
A change in color after 48 to 72 hours indicates what in the snyder test? |
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Definition
Moderate to slight susceptibility to dental caries |
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Term
What does the Kirby-Bauer test test for? |
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Definition
A microbes susceptibility to an antibiotic. |
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Term
Which media is used for the Kirby-Bauer test? |
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Definition
The Mueller-Hinton (MH) agar - pH 7.2-7.4 - beef extract, milk protein, starch. |
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Term
Why is MH used in the Kirby-Bauer test? |
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Definition
Has low variation, allows growth of a variety of organisms. |
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Term
What variables can affect the zone of inhibition in the kirby-bauer test? |
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Definition
Number of bacterial cells, thickness of the agar and the growth phase of the microorganism. |
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Term
What phase of growth must the microbe be in during the kirby-bauer test? Why? |
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Definition
Logarithmic - because this is when they are the most susceptible to antimicrobial agents. |
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Term
p. aeroginosa is a __________ __________ and is resistant to all antibiotics tested except for ______________ |
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Definition
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Term
B. cereus is a ____________ ____________ and is resistant to only ___________ and _____________. |
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Definition
Gram + Rod, penicillin and trimethoprim |
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Term
S. aureus is a ________________ _____________ and is resistant to only ______________. |
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Definition
Gram + rod, chloremphenicol |
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Term
Where does S. aureus live? |
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Definition
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Term
MRSA is resistant to many __________ antibiotics? |
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Definition
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Term
What does the femB gene encode for? |
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Definition
The S. aureus-specific enzyme |
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Term
If MRSA is present in a gel electrophoresis, what will be observed? |
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Definition
A mark at the femB gene, and mark at the mecA gene and a mark at the 16s rRNA gene |
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Term
How does a PEA plate inhibit gram negatives? |
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Definition
Phenylethyl alcohol breaks down the outer membrane and cytoplasmic membrane of gram negatives. |
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Term
On an MSA plate if the colonies are clear and the background is pink -red. |
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Definition
Microbes don't ferment mannitol |
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Term
On an MSA plate if the colonies are clear and the medium turns from red to yellow. |
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Definition
Microbe ferments mannitol |
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Term
If a microbe doesn't grow on a PEA plate it is.... |
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Definition
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Term
What is the selective agent in MacConkey Agar? |
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Definition
Crystal violet and bile salts that inhibit growth of gram pos microorganisms |
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Term
What are the differential agents in macConkey Agar? |
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Definition
lactose and PH natural red |
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Term
On macConkey agar the colonies are mauve on a mauve medium |
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Definition
Gram negative that doesn't ferment lactose |
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Term
If a microbe doesn't grow on MacConkey Agar it is.... |
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Definition
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Term
On macConkey agar, the media color is yellow.. |
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Definition
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Term
What is the selective agent in HEA? |
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Definition
Bile salts- prevent gram + |
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Term
What are the differential agents in HEA? |
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Definition
carbs and bromophenol blue
and ferric ammonium citrate and sodium thiosulfate |
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Term
If the media is yellow on HEA agar? |
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Definition
enteric microbe that ferments carbs |
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Term
If the colonies are black on HEA agar? |
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Definition
salmonella!! - produces ferrous sulfide |
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Term
If a microbe doesn't grow on HE... |
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Definition
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Term
If both OF tubes are yellow.. |
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Definition
The microbe is a facultative aerobe |
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Term
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Definition
The microbe may use protein as a fermentation source |
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Term
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Definition
negative for mixed acid fermentation |
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Term
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Definition
Positive for mixed acid fermentation - enteric |
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Term
A VP tube has a little violet at the top |
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Definition
Positive for butanediol pathway. |
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Term
A microbe that hydrolyzes starch will look like what? |
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Definition
zone of clearing around growth- where microbe has eaten at starch |
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Term
Which antibiotics target protein synthesis? |
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Definition
chloramphenicol and tetracycline |
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Term
Which antibiotics prevents bacteria from synthesizing folic acid? |
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Definition
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