Question 1

A serum titer involves

Accepted Answer

A) serially diluting a serum sample. 
B) determining the lowest dilution of serum that produces a visible reaction. 
C) determining the highest dilution of antigen that produces a visible reaction. 
D) the Western Blot method. 
A) serially diluting a serum sample. 
B) determining the lowest dilution of serum that produces a visible reaction. 
C) determining the highest dilution of antigen that produces a visible reaction. 
D) the Western Blot method.

Question 2

Why do many physicians feel that stool cultures are not necessary, except in certain circumstances when diagnosing GI tract infections?

Accepted Answer

Many physicians feel that stool cultures

Question 3

A physician orders an antistreptolysin O (ASO) titer test to check for rheumatic fever.A patient serum sample is exposed to known suspensions of streptolysin and then allowed to incubate with RBCs.If the patient does have rheumatic fever, what will happen?

Accepted Answer

A) Not enough information is provided to speculate. 
B) The red blood cells will lyse. 
C) The red blood cells will agglutinate only. 
D) The red blood cells will not lyse. 
E) The red blood cells will fluoresce. 
A) Not enough information is provided to speculate. 
B) The red blood cells will lyse. 
C) The red blood cells will agglutinate only. 
D) The red blood cells will not lyse. 
E) The red blood cells will fluoresce.

Question 4

In indirect fluorescent testing, fluorescent _____ are used to react with the Fc region of another, specific, serum antibody.

Accepted Answer

The answer of In indirect fluorescent testing, fluorescent _____ are...

Question 5

Serological testing always involves reactions between specific antibody and antigen.

Accepted Answer

A) True 
 B)False

Question 6

Maggie was told she has a positive titer to measles.Which of the following could explain this?

Accepted Answer

A) She was vaccinated against measles. 
B) She had measles sometime in her life. 
C) She has measles now. 
D) The test was a false positive. 
E) All of these choices are correct. 
A) She was vaccinated against measles. 
B) She had measles sometime in her life. 
C) She has measles now. 
D) The test was a false positive. 
E) All of these choices are correct.

Question 7

Culture of patient specimens to detect pathogens is usually done on blood agar plates only.

Accepted Answer

A) True 
 B)False

Question 8

Describe the indirect ELISA test that is used as a screening test for HIV (AIDS) and include the following: a) sequence of procedures, b) reagents used, and c) detection and interpretation of a positive test.

Accepted Answer

The indirect ELISA test for HIV (AIDS) i

Question 9

Which of the following is not a biochemical test used to identify a pathogen?

Accepted Answer

A) acid-fast reaction 
B) hydrolysis of gelatin 
C) coagulase production 
D) indole production 
E) carbohydrate fermentation 
A) acid-fast reaction 
B) hydrolysis of gelatin 
C) coagulase production 
D) indole production 
E) carbohydrate fermentation

Question 10

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

Accepted Answer

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

Question 11

Horseradish peroxidase and alkaline phosphatase are enzymes used in _____ tests.

Accepted Answer

The answer of Horseradish peroxidase and alkaline phosphatase are enzymes...

Question 12

Which of the following is incorrect regarding the complement fixation test?

Accepted Answer

A) First antigen and antibody are allowed to react. 
B) Purified complement proteins are added to the antigen-antibody tube. 
C) Sheep red blood cells are added to the antigen-antibody-complement mixture. 
D) Hemolysis of the sheep red blood cells occurs in a positive test result. 
A) First antigen and antibody are allowed to react. 
B) Purified complement proteins are added to the antigen-antibody tube. 
C) Sheep red blood cells are added to the antigen-antibody-complement mixture. 
D) Hemolysis of the sheep red blood cells occurs in a positive test result.

Question 13

Identify, describe, and discuss the objectives of the three main categories of identifying infectious agents using specific examples.

Accepted Answer

The three main categories of identifying

Question 14

The Widal test is used for diagnosing salmonellosis.

Accepted Answer

A) True 
 B)False

Question 15

Precipitation tests involve all of the following, except

Accepted Answer

A) they rely on formation of visible clumps for detection. 
B) they include the VDRL test for syphilis. 
C) they are often performed in agar gels. 
D) they can be done in a test tube by carefully adding antiserum over antigen solution. 
E) a cloudy or opaque zone developing where antigen and antibody react. 
A) they rely on formation of visible clumps for detection. 
B) they include the VDRL test for syphilis. 
C) they are often performed in agar gels. 
D) they can be done in a test tube by carefully adding antiserum over antigen solution. 
E) a cloudy or opaque zone developing where antigen and antibody react.

Question 16

Affixing antigen to an inert particle such as a latex bead is sometimes used in which type of test?

Accepted Answer

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

Question 17

All of the following are routine biochemical tests to aid in identifying a species, except

Accepted Answer

A) motility. 
B) carbohydrate fermentation. 
C) catalase test. 
D) oxidase test. 
E) coagulase test. 
A) motility. 
B) carbohydrate fermentation. 
C) catalase test. 
D) oxidase test. 
E) coagulase test.

Question 18

Which of the following methods is categorized as a direct test in order to analyze a specimen?

Accepted Answer

A) catalase test 
B) Gram stain 
C) phage typing 
D) antimicrobic sensitivity 
E) production of gas 
A) catalase test 
B) Gram stain 
C) phage typing 
D) antimicrobic sensitivity 
E) production of gas

Question 19

In lab, a student observes some dull, wrinkled brown colonies growing on their agar.They Gram stain the sample and observe single bacilli.Their blood agar does not reveal any hemolysis while their MSA has growth and fermentation.Using the following table and the given observations, determine which microorganism this would most likely be. 
$$\begin{array} { | l | l | l | } 
\hline \text { Bacilli } & \text { B. cereus } & \text { B. subtilis } \
\hline \text { Colony morphology } & \text { Dull, frosted colonies } & \begin{array} { l } 
\text { Dull, wrinkled colonies cream to } \
\text { brown colors }
\end{array} \
\hline \text { Microscopic arrangement } & \text { Chains } & \text { Single bacilli } \
\hline \text { Catalase } & + & + \
\hline \text { Blood agar } & \text { Beta } & \text { Gamma } \
\hline \text { Mannitol salt agar } & -& + \text { growth and } + \text { fermentation } \
\hline
\end{array}$$ 
$\begin{array}{|l|r|}
\hline \text { Pseudomonas }&\text { P. aeruginosa }\
\hline \text { Catalase }&+\
\hline\text { Oxidase }&+\
\hline\text { Motile }&+\
\hline\text { Blood agar }&\text { Beta }\
\hline\text { Glucose fermentation }&+\
\hline\text { Escherichia }&\text { E. coli }\
\hline\text { Lactose fermentation }&+\
\hline\text { Motile }&+\
\hline\text { Citrate fermentation }&-\
\hline\text { Urease }&-\
\hline\text { Catalase }&+\
\hline
\end{array}$

Accepted Answer

A) E.coli 
B) Pseudomonas aeruginosa 
C) B.subtilis 
D) B.cereus 
A) E.coli 
B) Pseudomonas aeruginosa 
C) B.subtilis 
D) B.cereus

Question 20

Allergy testing, which is accomplished by injecting tiny amounts of allergen into the skin and examining the injection site for a reaction, is an example of an in vitro test.

Accepted Answer

A) True 
 B)False

Exam 17: Procedures for Identifying Pathogens and Diagnosing Infections

A serum titer involves

Why do many physicians feel that stool cultures are not necessary, except in certain circumstances when diagnosing GI tract infections?

A physician orders an antistreptolysin O (ASO) titer test to check for rheumatic fever.A patient serum sample is exposed to known suspensions of streptolysin and then allowed to incubate with RBCs.If the patient does have rheumatic fever, what will happen?

In indirect fluorescent testing, fluorescent _____ are used to react with the Fc region of another, specific, serum antibody.

Serological testing always involves reactions between specific antibody and antigen.

Maggie was told she has a positive titer to measles.Which of the following could explain this?

Culture of patient specimens to detect pathogens is usually done on blood agar plates only.

Describe the indirect ELISA test that is used as a screening test for HIV (AIDS) and include the following: a) sequence of procedures, b) reagents used, and c) detection and interpretation of a positive test.

Which of the following is not a biochemical test used to identify a pathogen?

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

Horseradish peroxidase and alkaline phosphatase are enzymes used in _____ tests.

Which of the following is incorrect regarding the complement fixation test?

Identify, describe, and discuss the objectives of the three main categories of identifying infectious agents using specific examples.

The Widal test is used for diagnosing salmonellosis.

Precipitation tests involve all of the following, except

Affixing antigen to an inert particle such as a latex bead is sometimes used in which type of test?

All of the following are routine biochemical tests to aid in identifying a species, except

Which of the following methods is categorized as a direct test in order to analyze a specimen?

Allergy testing, which is accomplished by injecting tiny amounts of allergen into the skin and examining the injection site for a reaction, is an example of an in vitro test.

The Main Themes of Microbiology

The Chemistry of Biology

Tools of the Laboratory: Methods of Studying Microorganisms

A Survey of Prokaryotic Cells and Microorganisms

A Survey of Eukaryotic Cells and Microorganisms

An Introduction to Viruses

Microbial Nutrition, Ecology, and Growth

An Introduction to Microbial Metabolism: the Chemical Crossroads of Life

Microbial Genetics

Genetic Engineering: a Revolution in Molecular Biology

Physical and Chemical Agents for Microbial Control

Drugs, Microbes, Host--The Elements of Chemotherapy

Microbe-Human Interactions: Infection and Disease

An Introduction to Host Defenses and Innate Immunities

Adaptive, Specific Immunity and Immunization

Disorders in Immunity

The Gram-Positive and Gram-Negative Cocci of Medical Importance

The Gram-Positive Bacilli of Medical Importance

The Gram-Negative Bacilli of Medical Importance

Miscellaneous Bacterial Agents of Disease

The Fungi of Medical Importance

The Parasites of Medical Importance

Introduction to Viruses That Infect Humans: the Dna Viruses

The Rna Viruses That Infect Humans

Environmental Microbiology

Applied and Industrial Microbiology

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