Question 1

Phenotypic testing is often beneficial in identifying infectious agents from patient samples; however, some disadvantages include

Accepted Answer

A)  organisms must be grown on the same culture media so it is difficult to distinguish them from each other.
B)  lengthy culturing times and the inability to grow some bacteria in vitro.
C)  difficulty in identifying motile organisms.
D)  non-specificity of some biochemical tests since all pathogens utilize the same substrate as a fuel source.E) B) and D)
F) A) and D) B

Question 2

Your daughter probably has strep throat caused by Streptococcus pyogenes.The traditional method of diagnosis involves culturing on blood agar, but this process is time consuming.Your doctor wants a more rapid identification of the infectious agent using a specimen directly obtained from the patient's throat.He would prefer to use a test that can be read in his office without having to culture and isolate the organism.He would likely choose the

Accepted Answer

A)  immunochromatographic test.
B)  Western Blot test.
C)  direct fluorescence test.
D)  pulse-field gel electrophoresis.E) All of the above
F) B) and D)

Question 3

The ELISA test has been used as the most common, rapid screening test for HIV infection.Its sensitivity is very high but its specificity is rather low (for an important identification test) .Which statement describes this accurately?

Accepted Answer

A)  Only certain kinds of instruments can be used to pick up the small amounts of fluorescence given off in the ELISA.
B)  The test can identify the patient's antibody to HIV only when it is large quantities.
C)  A false positive test result may develop due to the test antigens capturing normal antibodies.
D)  The patient's specimen has to be handled in a certain way to maintain the integrity of the viral DNA.E) A) and B)
F) A) and C)

Question 4

Alkaline phosphatase is an enzyme used in _____ tests.

Accepted Answer

A)  indirect fluorescent antibody
B)  ELISA
C)  Western blot
D)  direct fluorescent antibodyE) A) and B)
F) A) and C)

Question 5

An infectious organism isolated from a patient has a sequence on its genome TATTGAAGC.This will hybridize to the RNA probe UAUUGAAGC.

Accepted Answer

A) True 
 B)False

Question 6

The indirect ELISA test is commonly used to diagnose infections caused by all of the following except ______.

Accepted Answer

A)  hepatitis A virus
B)  rubella virus
C)  hepatitis C virus
D)  HIV
E)  HelicobacterF) A) and B)
G) B) and D)

Question 7

The tuberculin test is an example of an in vitro serological test.

Accepted Answer

A) True 
 B)False

Question 8

Soluble antigens are detected in what type of test?

Accepted Answer

A)  Specificity
B)  Cross-reactions
C)  Agglutination
D)  Precipitation
E)  SensitivityF) A) and D)
G) C) and E) D

Question 9

Biochemical tests include all of the following except

Accepted Answer

A)  gas production tests.
B)  sugar fermentation tests.
C)  antibiotic sensitivity tests.
D)  ribotyping tests.
E)  tests for the presence of specific enzymes.F) All of the above
G) A) and C)

Question 10

Viruses can be used to identify bacteria because of viral specificity for a host cell.This identification method is called ______.

Accepted Answer

A)  phage typing
B)  probing
C)  ELISA
D)  immunochromatographyE) None of the above
F) All of the above

Question 11

In vivo testing is useful for diagnosing ______.

Accepted Answer

A)  hepatitis A
B)  HIV
C)  tuberculosis
D)  whooping cough
E)  rubellaF) A) and B)
G) A) and E)

Question 12

When minute samples of DNA need to be genetically analyzed for identification purposes, which test can be effectively used?

Accepted Answer

A)  Weil-Felix reaction
B)  PCR
C)  Direct fluorescence antibody
D)  Western Blot
E)  WidalF) C) and E)
G) All of the above

Question 13

What type of test will detect cell-associated antigens?

Accepted Answer

A)  Cross-reaction
B)  Sensitivity
C)  Agglutination
D)  Precipitation
E)  SpecificityF) C) and E)
G) D) and E)

Question 14

The ELISA is commonly used for diagnosing salmonellosis.

Accepted Answer

A) True 
 B)False

Question 15

In precipitation tests, the antigen

Accepted Answer

A)  -antibody complex settles to the bottom of the tube.
B)  is a whole cell.
C)  is an insoluble molecule.
D)  is a soluble molecule.E) None of the above
F) A) and C)

Question 16

The property of a test to detect only a certain antibody or antigen and not to react with any others is ______.

Accepted Answer

A)  specificity
B)  sensitivity
C)  cross-reaction
D)  agglutination
E)  precipitationF) A) and C)
G) D) and E)

Question 17

The difference between direct and indirect immunofluorescence testing is that

Accepted Answer

A)  	Direct testing adds antibodies directly to antigens, whereas indirect testing cultures the organisms first and adds fluorescent tags to the patient sample.
B)  	Direct testing determines the identity of an unknown antibody in a patient sample, whereas indirect testing determines whether the patient is infected with a specific antigen.
C)  	Indirect testing determines the identity of an unknown antigen in a patient sample, whereas direct testing.determines whether the patient has been exposed to an antigen as evidenced by the presence of antibodies in their sera.
D)  	Direct testing determines the identity of an unknown antigen in a patient sample, whereas indirect testing.determines whether the patient has been exposed to an antigen as evidenced by the presence of antibodies in their sera.E) B) and D)
F) A) and D)

Question 18

Which of these tests is an in vivo test?

Accepted Answer

A)  Tuberculin test
B)  Western Blot
C)  Agglutination test
D)  PCRE) B) and C)
F) A) and B)

Question 19

Which statement about clinical identification tests is true?

Accepted Answer

A)  Microarray tests are based on electrophoresis methodology.
B)  Serological tests are always based on identifying antibodies in the patient.
C)  Biochemical tests are quicker than genetic analysis tests.
D)  Not all diseases are identified by clinical tests.E) B) and D)
F) B) and C)

Question 20

Serological testing relies upon

Accepted Answer

A)  the specificity of the Fc region of antibodies.
B)  a patient who is not immunocompromised.
C)  the specificity of the variable regions of antibodies.
D)  a very high viral or bacterial load in the patient.E) B) and C)
F) C) and D) C

Exam 17: Diagnosing Infections

Phenotypic testing is often beneficial in identifying infectious agents from patient samples; however, some disadvantages include

Correct Answer
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B

Correct Answer
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The ELISA test has been used as the most common, rapid screening test for HIV infection.Its sensitivity is very high but its specificity is rather low (for an important identification test) .Which statement describes this accurately?

Correct Answer
verified

Alkaline phosphatase is an enzyme used in _____ tests.

Correct Answer
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An infectious organism isolated from a patient has a sequence on its genome TATTGAAGC.This will hybridize to the RNA probe UAUUGAAGC.

Correct Answer
verified

The indirect ELISA test is commonly used to diagnose infections caused by all of the following except ______.

Correct Answer
verified

The tuberculin test is an example of an in vitro serological test.

Correct Answer
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Soluble antigens are detected in what type of test?

Correct Answer
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D

Biochemical tests include all of the following except

Correct Answer
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Viruses can be used to identify bacteria because of viral specificity for a host cell.This identification method is called ______.

Correct Answer
verified

In vivo testing is useful for diagnosing ______.

Correct Answer
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When minute samples of DNA need to be genetically analyzed for identification purposes, which test can be effectively used?

Correct Answer
verified

What type of test will detect cell-associated antigens?

Correct Answer
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The ELISA is commonly used for diagnosing salmonellosis.

Correct Answer
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In precipitation tests, the antigen

Correct Answer
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The property of a test to detect only a certain antibody or antigen and not to react with any others is ______.

Correct Answer
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The difference between direct and indirect immunofluorescence testing is that

Correct Answer
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Which of these tests is an in vivo test?

Correct Answer
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Which statement about clinical identification tests is true?

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Serological testing relies upon

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C

Exam 17: Diagnosing Infections

Phenotypic testing is often beneficial in identifying infectious agents from patient samples; however, some disadvantages include

Correct AnswerverifiedB

Correct AnswerverifiedShow Answer

The ELISA test has been used as the most common, rapid screening test for HIV infection.Its sensitivity is very high but its specificity is rather low (for an important identification test) .Which statement describes this accurately?

Correct AnswerverifiedShow Answer

Alkaline phosphatase is an enzyme used in _____ tests.

Correct AnswerverifiedShow Answer

An infectious organism isolated from a patient has a sequence on its genome TATTGAAGC.This will hybridize to the RNA probe UAUUGAAGC.

Correct AnswerverifiedShow Answer

The indirect ELISA test is commonly used to diagnose infections caused by all of the following except ______.

Correct AnswerverifiedShow Answer

The tuberculin test is an example of an in vitro serological test.

Correct AnswerverifiedShow Answer

Soluble antigens are detected in what type of test?

Correct AnswerverifiedD

Biochemical tests include all of the following except

Correct AnswerverifiedShow Answer

Viruses can be used to identify bacteria because of viral specificity for a host cell.This identification method is called ______.

Correct AnswerverifiedShow Answer

In vivo testing is useful for diagnosing ______.

Correct AnswerverifiedShow Answer

When minute samples of DNA need to be genetically analyzed for identification purposes, which test can be effectively used?

Correct AnswerverifiedShow Answer

What type of test will detect cell-associated antigens?

Correct AnswerverifiedShow Answer

The ELISA is commonly used for diagnosing salmonellosis.

Correct AnswerverifiedShow Answer

In precipitation tests, the antigen

Correct AnswerverifiedShow Answer

The property of a test to detect only a certain antibody or antigen and not to react with any others is ______.

Correct AnswerverifiedShow Answer

The difference between direct and indirect immunofluorescence testing is that

Correct AnswerverifiedShow Answer

Which of these tests is an in vivo test?

Correct AnswerverifiedShow Answer

Which statement about clinical identification tests is true?

Correct AnswerverifiedShow Answer

Serological testing relies upon

Correct AnswerverifiedC

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B

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D

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C