Question 1

The Western blot test is conﬁrmatory for HIV because it ______.

Accepted Answer

A)   is more sensitive than the ELISA
B)   has fewer false positives than the ELISA
C)   requires electrophoresis, whereas the ELISA does not
D)   uses an indicator of some sort to visualize the antibody
E)   All of the choices are correct.

Question 2

Which sample is not collected by sterile needle aspiration?

Accepted Answer

A)   Blood
B)   Urine
C)   Cerebrospinal ﬂuid
D)   Tissue ﬂuids
E)   All of the choices are collected by sterile needle aspiration.

Question 3

In your microbiology lab, your class is identifying bacteria. You are using dichotomous keys to aid in the identi?cation process using the data from a variety of biochemical tests. What problems do you foresee in this procedure?

Accepted Answer

A)   Dichotomous keys are too sophisticated to read properly, so you are worried that there will be a large degree of error in your identi?cation.
B)   Dichotomous keys are not valid for identi?cation.
C)   If you misread a biochemical test or write down the wrong result, the key will likely take you to an alternative organism that is not your unknown bacterium.
D)   The dichotomous key does not contain information on your bacterium.

Question 4

Microarrays, hybridization tests, and ribotyping are increasing in frequency in their use in clinical labs for diagnosis of infectious diseases and the microorganisms causing them. Why is this?

Accepted Answer

A)   The tests are more easily performed in a doctor's oﬃce or hospital, right there where the specimens are taken.
B)   They are cheaper than biochemical tests.
C)   Genomic testing has less errors compared to biochemical tests and serological tests.
D)   They have greater speciﬁcity for the organism because they employ speciﬁc antibody.

Question 5

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 identi?cation 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 o?ce without having to culture and isolate the organism. He would likely choose the ______.

Accepted Answer

A)   immunochromatographic test
B)   direct ?uorescence test
C)   Western Blot test
D)   pulse-?eld gel electrophoresis

Question 6

The property of a test to detect even small amounts of antibodies or antigens that are test targets is ______.

Accepted Answer

A)   cross-reaction
B)   agglutination
C)   precipitation
D)   speciﬁcity
E)   sensitivity

Question 7

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

Accepted Answer

A)   immunochromatography
B)   probing
C)   ELISA
D)   phage typing

Question 8

Which of the following is not a phenotypic method of identiﬁcation?

Accepted Answer

A)   Acid-fast reaction
B)   Gram stain reaction
C)   Endospore production
D)   Morphology
E)   Antibody response

Question 9

A serum titer involves ______.

Accepted Answer

A)   quantifying the number of infectious particles in a specimen
B)   determining the lowest dilution of serum that produces a visible reaction
C)   determining the highest dilution of serum that produces a visible reaction
D)   the Western blot method

Question 10

Phage typing is useful in identifying ______.

Accepted Answer

A)   Treponema pallidum
B)   Mycobacterium leprae
C)   Clostridium
D)   Streptococcus pyogenes
E)   Salmonella

Question 11

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

Accepted Answer

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

Question 12

The gene that codes for the bacterial 16s RNA molecule is highly conserved across species, but also contains hypervariable regions that are highly species-speci?c. FISH analysis of rRNA is bene?cial because ______.

Accepted Answer

A)   it can narrow down the list of potential infectious organisms to three or four
B)   it can precisely identify the 16s sequences from patient samples without the lag time it takes to culture the organism
C)   it is much cheaper than traditional analytical methods
D)   it incorporates both direct testing and serological testing for added accuracy

Question 13

If you were going to identify microorganisms within a specimen containing large numbers of organisms (seawater, normal microbiota, etc.) , you would have to ______.

Accepted Answer

A)   use different kinds of serological tests
B)   amplify gene sequences within the sample to identify each of the different organisms
C)   use a wide variety of microbiological media to identify all of the different species of microorganisms
D)   use a wide variety of antibodies to react with the antigens

Question 14

The tuberculin skin test is read ______.

Accepted Answer

A)   within 1 hour
B)   after 12 hours
C)   from 12-24 hours
D)   from 24-48 hours
E)   from 48-72 hours

Question 15

You place an inoculum of your bacterium on a glass slide and add a drop of hydrogen peroxide reagent. Promptly you see bubbles appear, indicating the presence of a particular enzyme that the bacterium produces. What type of identi?cation test does this exemplify?

Accepted Answer

A)   Immunochromatography
B)   Biochemical test
C)   Microarray
D)   Precipitation test

Question 16

A positive serological test for tuberculosis indicates that the patient ______.

Accepted Answer

A)   is an asymptomatic carrier of tuberculosis
B)   is immune to tuberculosis
C)   has active tuberculosis
D)   has been exposed to tuberculosis

Question 17

Which statement about clinical identiﬁcation tests is true?

Accepted Answer

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

Question 18

All of the following are routinely collected for microbial analysis of a specimen except ______.

Accepted Answer

A)   saliva
B)   skin
C)   blood
D)   hair
E)   spinal ﬂuid

Question 19

Nucleic acid testing is appropriate as a testing method when one is not sure what microorganisms are present in the specimen.

Accepted Answer

A) True 
 B)False

Question 20

A method of identi?cation using immobilized, known antigens to identify unknown antibodies and vice versa, where the presence of the agent being tested for immediately brings about a color change is called ______.

Accepted Answer

A)   ELISA
B)   radioimmunoassay
C)   immunochromatography
D)   Western blotting

Exam 17: Diagnosing Infections

Correct Answer
verified

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

Correct Answer
verified

Which statement about clinical identiﬁcation tests is true?

Correct Answer
verified

A positive serological test for tuberculosis indicates that the patient ______.

Correct Answer
verified

Which sample is not collected by sterile needle aspiration?

Correct Answer
verified

The tuberculin skin test is read ______.

Correct Answer
verified

A method of identi?cation using immobilized, known antigens to identify unknown antibodies and vice versa, where the presence of the agent being tested for immediately brings about a color change is called ______.

Correct Answer
verified

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

Correct Answer
verified

Microarrays, hybridization tests, and ribotyping are increasing in frequency in their use in clinical labs for diagnosis of infectious diseases and the microorganisms causing them. Why is this?

Correct Answer
verified

You place an inoculum of your bacterium on a glass slide and add a drop of hydrogen peroxide reagent. Promptly you see bubbles appear, indicating the presence of a particular enzyme that the bacterium produces. What type of identi?cation test does this exemplify?

Correct Answer
verified

All of the following are routinely collected for microbial analysis of a specimen except ______.

Correct Answer
verified

In your microbiology lab, your class is identifying bacteria. You are using dichotomous keys to aid in the identi?cation process using the data from a variety of biochemical tests. What problems do you foresee in this procedure?

Correct Answer
verified

The gene that codes for the bacterial 16s RNA molecule is highly conserved across species, but also contains hypervariable regions that are highly species-speci?c. FISH analysis of rRNA is bene?cial because ______.

Correct Answer
verified

The property of a test to detect even small amounts of antibodies or antigens that are test targets is ______.

Correct Answer
verified

If you were going to identify microorganisms within a specimen containing large numbers of organisms (seawater, normal microbiota, etc.) , you would have to ______.

Correct Answer
verified

The Western blot test is conﬁrmatory for HIV because it ______.

Correct Answer
verified

Which of the following is not a phenotypic method of identiﬁcation?

Correct Answer
verified

A serum titer involves ______.

Correct Answer
verified

Nucleic acid testing is appropriate as a testing method when one is not sure what microorganisms are present in the specimen.

Correct Answer
verified

Phage typing is useful in identifying ______.

Correct Answer
verified

Exam 17: Diagnosing Infections

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 speci?city is rather low (for an important identi?cation test) . Which statement describes this accurately?

Correct AnswerverifiedShow Answer

Which statement about clinical identiﬁcation tests is true?

Correct AnswerverifiedShow Answer

A positive serological test for tuberculosis indicates that the patient ______.

Correct AnswerverifiedShow Answer

Which sample is not collected by sterile needle aspiration?

Correct AnswerverifiedShow Answer

The tuberculin skin test is read ______.

Correct AnswerverifiedShow Answer

A method of identi?cation using immobilized, known antigens to identify unknown antibodies and vice versa, where the presence of the agent being tested for immediately brings about a color change is called ______.

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

Microarrays, hybridization tests, and ribotyping are increasing in frequency in their use in clinical labs for diagnosis of infectious diseases and the microorganisms causing them. Why is this?

Correct AnswerverifiedShow Answer

You place an inoculum of your bacterium on a glass slide and add a drop of hydrogen peroxide reagent. Promptly you see bubbles appear, indicating the presence of a particular enzyme that the bacterium produces. What type of identi?cation test does this exemplify?

Correct AnswerverifiedShow Answer

All of the following are routinely collected for microbial analysis of a specimen except ______.

Correct AnswerverifiedShow Answer

In your microbiology lab, your class is identifying bacteria. You are using dichotomous keys to aid in the identi?cation process using the data from a variety of biochemical tests. What problems do you foresee in this procedure?

Correct AnswerverifiedShow Answer

The gene that codes for the bacterial 16s RNA molecule is highly conserved across species, but also contains hypervariable regions that are highly species-speci?c. FISH analysis of rRNA is bene?cial because ______.

Correct AnswerverifiedShow Answer

The property of a test to detect even small amounts of antibodies or antigens that are test targets is ______.

Correct AnswerverifiedShow Answer

If you were going to identify microorganisms within a specimen containing large numbers of organisms (seawater, normal microbiota, etc.) , you would have to ______.

Correct AnswerverifiedShow Answer

The Western blot test is conﬁrmatory for HIV because it ______.

Correct AnswerverifiedShow Answer

Which of the following is not a phenotypic method of identiﬁcation?

Correct AnswerverifiedShow Answer

A serum titer involves ______.

Correct AnswerverifiedShow Answer

Nucleic acid testing is appropriate as a testing method when one is not sure what microorganisms are present in the specimen.

Correct AnswerverifiedShow Answer

Phage typing is useful in identifying ______.

Correct AnswerverifiedShow Answer

Correct Answer
verified

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