Full Test Bank Diagnosing Infections Ch.15 Cowan

Microbiology Fundamentals: A Clinical Approach, 3e (Cowan)

Chapter 15 Diagnosing Infections

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

A) Morphology

B) Gram stain reaction

C) Acid-fast reaction

D) Antibody response

E) Endospores

2) Biochemical tests include all of the following except ________.

A) presence of catalase

B) presence of oxidase

C) colony morphology

D) sugar fermentation

E) gas production

3) The primary advantage of genotypic methods of identification is ________.

A) they are easier than any other method

B) they are less expensive than other methods

C) they are widely available

D) culturing of the organism is not required

E) All of the choices are correct.

4) Specimen collection ________.

A) is always done by a medical professional

B) must be done under sterile conditions

C) must utilize aseptic techniques

D) does not require special handling

E) All of the choices are correct.

5) Each of the following are appropriate specimens for bacterial culture except ________.

A) saliva

B) skin

C) spinal fluid

D) hair

E) throat

6) Which sample is not typically collected by sterile needle aspiration?

A) Blood

B) Urine

C) Cerebrospinal fluid

D) Tissue fluids

E) All of the choices are collected by sterile needle aspiration.

7) Urine and fecal specimens require ________.

A) sterile collection conditions

B) incubation in differential media

C) incubation in selective media

D) both sterile collection conditions and incubation in differential media

E) both incubation in differential media and incubation in selective media

8) Phage typing is useful in identifying ________.

A) Treponema pallidum

B) Mycobacterium leprae

C) Streptococcus

D) Salmonella

E) Clostridium

9) Animals are required for the cultivation of ________.

A) Treponema pallidum

B) Pseudomonas

C) Streptococcus

D) Salmonella

E) Clostridium

10) Which test is especially good for bacteria that are not readily cultivated in the lab?

A) Gram stain

B) Direct antigen testing

C) Dichotomous key

D) Direct fluorescence antibody (DFA) testing

E) Phage test

11) Which of the following is not a genotypic method of identification?

A) rRNA sequencing

B) PCR

C) Biosensor

D) Direct antigen testing

E) DNA analysis with probes

12) Which of the following is involved in the in vitro diagnostic testing of serum?

A) Mycology

B) Hematology

C) Serology

D) Histology

E) Virology

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

A) cross reaction

B) agglutination

C) precipitation.

D) specificity

E) sensitivity

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

A) cross reaction

B) agglutination

C) precipitation

D) specificity

E) sensitivity

15) A serum titer involves ________.

A) serially diluting a serum sample

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

E) None of the choices are correct.

16) A positive serological test for tuberculosis indicates that ________.

A) the patient has active tuberculosis

B) the patient is an asymptomatic carrier of tuberculosis

C) the patient has been exposed to tuberculosis

D) All of the choices are correct.

17) Serological testing can be used to test each of the following except ________.

A) blood serum

B) cerebrospinal fluid

C) urine

D) saliva

E) skin

18) Titer is the amount of ________.

A) antigen in serum

B) antibody in serum

C) WBC in serum

D) complement in serum

E) memory cells in serum

19) Serological testing relies upon ________.

A) the specificity of the Fc region of antibodies

B) the specificity of the variable regions of antibodies

C) a patient who is not immunocompromised

D) very high viral or bacterial load in the patient

E) None of the choices are correct.

20) Antibody testing requires ________.

A) a known antigen

B) a known antibody

C) both a known antigen and a known antibody

D) either a known antigen or a known antibody

21) What type of test will detect whole antigens?

A) Cross reaction

B) Agglutination

C) Precipitation

D) Specificity

E) Sensitivity

22) Soluble antigens are detected in this type of test.

A) Cross reactions

B) Agglutination

C) Precipitation

D) Specificity

E) Sensitivity

23) Precipitation tests involve all of the following except ________.

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

24) In precipitation tests, the antigen ________.

A) is a soluble molecule

B) is an insoluble molecule

C) is a whole cell

D) antibody complex settles to the bottom of the tube

E) None of the choices are correct.

25) Syphilis can be diagnosed most easily by ________.

A) the Weil-Felix reaction

B) direct fluorescence

C) ELISA

D) agglutination

E) immunochromatography

26) Which test is the confirming test for people who initially tested antibody-positive in the screening ELISA test for HIV?

A) Immunochromatography

B) Western blot

C) Immunelectrophoresis

D) Radioimmunoassay (RIA)

E) Weil-Felix

27) The Western blot test is confirmatory for HIV because ________.

A) it is more sensitive than the ELISA

B) it has fewer false positives than the ELISA

C) it tests for more HIV antibodies than ELISA

D) it is easier to interpret than ELISA

E) All of the choices are correct.

28) Which test uses radioactive isotopes to label antibodies or antigens in order to detect minute amounts of corresponding antigen or antibody?

A) Immunochromatography

B) Western blot

C) Immunelectrophoresis

D) Radioimmunoassay (RIA)

E) ELISA

29) Horseradish peroxidase and alkaline phosphatase are enzymes used in ________ tests.

A) Western blot

B) ELISA

C) direct fluorescent antibody

D) indirect fluorescent antibody

E) None of the choices are correct.

30) A positive indirect  ELISA result requires ________.

A) one known antibody, one unknown antibody, and an unknown antigen

B) a known antigen, an unknown antibody, and a known antibody

C) two known antibodies and one known antigen

D) two known antibodies and one unknown antigen

E) All of the choices are correct.

31) The indirect ELISA test is used to diagnose all of the following except ________.

A) strep throat

B) HIV

C) hepatitis A and C

D) Helicobacter

E)  Rickettsia

32) In vivo testing is useful for diagnosing ________.

A) tuberculosis

B) rubella virus

C) hepatitis A

D) HIV

E) whooping cough

33) The tuberculin skin test is read ________.

A) within 1 hour

B) after 12 hours

C) from 12 to 24 hours

D) from 24 to 48 hours

E) from 48 to 72 hours

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

A) Direct fluorescence antibody

B) Immunofluorescence

C) Weil-Felix reaction

D) PCR

E) Direct antigen reaction

35) It is necessary to do lab tests to diagnose all diseases.

36) When antibodies or other substances in serum cross-react with the test reagents, a false positive result can occur.

37) Serological testing always involves reactions between specific antibody and antigen.

38) Serological tests should have low sensitivity and specificity.

39) The Weil-Felix test is used for diagnosing salmonellosis.

40) Fluorescent dye can be used as a label to trace antibody-antigen reactions in an ELISA assay.

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

42) The three main techniques for identifying microbes are ________.

A) phenotypic, immunologic, and genotypic

B) microscopic, macroscopic, and biochemical

C) PCR, electrophoresis, and biochemical

D) DNA, RNA, and antibodies

43) Which of the following is not one of the main categories for identifying microbes?

A) Radiologic

B) Phenotypic

C) Genotypic

D) Immunologic

44) The three main techniques for identifying microorganisms from patient samples are specificity, sensitivity, and biochemical.

45) Phenotypic methods of identifying microorganisms in a patient sample are characterized as those that ________.

A) directly examine the organism's appearance or behavior, which includes its metabolic abilities, environmental preferences and drug susceptibilities

B) analyze the genetic makeup of the microorganism, which conclusively diagnoses the infection

C) make use of the patient's antibodies to precipitate the microorganism out of solution, or agglutinate the antigens in the sample

D) make use of color-changing antibodies directed against the microbe that will become visible to the naked eye when bound

46) Immunologic methods of identifying microorganisms in a patient sample are characterized as those that ________.

A) rely on the specificity of antibodies to target a single antigen

B) directly examine the organism's appearance or behavior, which includes its metabolic abilities, environmental preferences and drug susceptibilities

C) analyze the genetic makeup of the microorganism, which conclusively diagnoses the infection

D) amplifies the microbial DNA in the patient's sample and during the process, identifies the organism through the use of known primers

47) Microorganisms can be identified from a patient sample using biochemical tests based on the premise that ________.

A) organisms have a unique combination of metabolic enzymes that are displayed when color-changing dyes are utilized to demonstrate their physiological response to specific substrates

B) organisms display specific antigens that can be bound by color-changing antibodies that allow the clinician to locate and identify the pathogen

C) organisms will not grow on certain media types and can be selected for on others

D) bacteriophages infect certain bacterial cells and the specificity can be used to identify the organism

48) Microbes can be identified using automated biochemical tests, often without incubation.  An example of this type of test would include ________.

A) a test for the presence of the enzyme urease, that would change the media from yellow to red

B) binding of fluorescent antibodies to the specific antigenic determinant in the sample

C) exposure to DNA probes that are either fluorescently labeled or will initiate a color change when bound to their complement

D) digestion of the genomic DNA by restriction enzymes, followed by separation by gel electrophoresis

49) If a phenotypic analysis requires culturing the organism before testing can begin, this is problematic for two reasons; i) rapid diagnosis may be critical and culturing can take up to 24 hours, and ii) a successful in vitro culturing method for a specific pathogen may not be feasible.

50) Techniques that make use of probes that hybridize to specific sequences of a pathogen's genome include ________.

A) FISH and microarrays

B) ELISA and FISH

C) FISH and Western blot

D) PFGE and ELISA

51) FISH and microarrays both use probes to hybridize to sequences of the pathogen genome.  They differ in that ________.

A) FISH involves adding fluorescently labeled probes directly to a patient's sample, whereas microarrays involve the attachment of thousands of potential gene sequences from pathogens to an absorbent plate and adding DNA from the patient's sample to it, allowing matching sequences to hybridize

B) microarrays involve adding fluorescently labeled probes directly to a patient's sample, whereas FISH involves the attachment of thousands of potential gene sequences from pathogens to an absorbent plate and adding DNA from the patient's sample to it, allowing matching sequences to hybridize

C) FISH involves scanning and analyzing the pathogen genome multiple times, whereas microarrays involve separating DNA samples into fragments using restriction enzymes, then exposing the fragments to varying voltage levels from three different directions

D) microarrays involve scanning and analyzing the pathogen genome multiple times, whereas FISH involves separating DNA samples into fragments using restriction enzymes, then exposing the fragments to varying voltage levels from three different directions

52) An outbreak of hepatitis A originating in a popular chain of restaurants serving fresh produce necessitated the rapid analysis of the viral genome in order to trace its source.  The genome was scanned and analyzed multiple times to reduce errors.  This is an example of ________.

A) whole genome sequencing

B) PFGE

C) FISH

D) microarrays

53) The value of whole genome sequencing is that it can separate larger strands of DNA by slowly applying alternating voltage levels from three different directions.

54) An outbreak of E. coli 0157:H7 was suspected to be associated with the petting zoo enclosure at the state fair.  Epidemiologists with the CDC created a DNA fingerprint from the E. coli isolated from patients and compared it to bacterial isolates analyzed by national laboratories.  They confirmed that the organism was indeed being transmitted by the animals at the fair.  The CDC uses what method to generate these fingerprints?

A) PFGE

B) FISH

C) Microarray

D) Hybridization

55) The CDC operates a national laboratory network called PulseNet, that compiles DNA fingerprinting data and connects foodborne illness cases so outbreaks can be detected rapidly.

56) The benefit of "lab on a chip" technology over standard microarrays is that ________.

A) lab on a chip technology has miniaturized testing to carry out analyses using minute amounts of reagents, whereas microarrays still require larger volumes of reagents in comparison

B) lab on a chip technology requires little technical training compared to analyses using microarrays

C) lab on a chip technology is invaluable for developing countries, where the reagents, refrigeration and trained personnel required for microarrays are limited

D) All of the choices are benefits of "lab on a chip" technology.

57) The ability to miniaturize genetic testing on a chip much smaller than a microarray plate will see its greatest benefit in developed countries so the large corporations can process genetic data much more efficiently.

58) A protein fingerprint of a patient's blood sample can be created by adding the sample to a metal plate and striking it with a laser. This causes the sample to become ionized and the ions from the sample are guided into a machine that separates them and identifies them according to their mass-to-charge ratio.  This process describes ________.

A) MALDI-TOF

B) "lab on a chip"

C) PFGE

D) PCR

E) FISH

59) MRI, CT and PET scans are useful diagnostic tools in cases where infection is located in deep tissues, thereby saving the patient from an invasive biopsy.

NCLEX Prep - Test Bank Question:  Please read the clinical scenario, and then answer the questions that follow to become familiar with the traditional NCLEX question format.

A student nurse on a medical-surgical floor is caring for a 62-year-old previously healthy female. The patient has been admitted for an infectious disease work-up. She has been experiencing generalized pain and nausea for the past three weeks, and recently developed a fever. The student nurse prepares to assist the RN in collecting blood for the following lab tests: complete blood count (CBC), C-reactive protein (CRP), eosinophil sedimentation rate (ESR), blood culture, urine culture, and a lumbar puncture with cerebral spinal fluid (CSF) culture and cell count. The nurse is also collecting a sputum culture, as well as a respiratory PCR by nasopharyngeal suction.

60) The patient's CRP is markedly elevated. What does this indicate? 

A) An elevated CRP is a highly sensitive urinary tract infection marker.

B) An elevated CRP points to inflammation from any of a variety of sources.

C) An elevated CRP is diagnostic of a fungal infection.

D) An elevated CRP is diagnostic of a bacterial infection.

61) The patient's urine culture was collected using a clean-catch method. After inoculation and incubation, several organisms were identified in amounts that were reported as normal microbial flora. Which of the following statements by the student nurse indicates proper understanding of the findings?

A) The patient is superinfected and needs immediate antimicrobial treatment.

B) The specimen was contaminated and another clean-catch urine specimen needs to be cultured.

C) The results point to an infection, but due to multiple organisms, further testing needs to be done to isolate the offending microbe.

D) This is a common finding due to contamination of a clean-catch urine sample with normal microbiota from the urogenital area.

62) The patient's respiratory PCR results are reported as "insufficient cells available for testing." Which of the following statements by the student nurse indicates proper understanding of the findings? 

A) The patient is free of infection since insufficient cells could be isolated.

B) A smaller sample must be sent, since the irrigation solution volume diluted the cells.

C) This is a very specific and sensitive finding that points to a viral infection.

D) The sample was inadequate, and the nasopharyngeal specimen collection must be repeated.

63) The lumbar puncture was especially uncomfortable for the patient. What step listed below is most important to be taken to ensure the procedure does not need to be repeated?  

A) The specimens must be properly labeled.

B) The specimens must be properly obtained and stored.

C) The specimens must be collected in sufficient amounts.

D) The specimens must be properly transported.

E) All of the choices are equally important.

NCLEX Prep - Test Bank Question:  Please read the clinical scenario, and then answer the questions that follow to become familiar with the traditional NCLEX question format.

The public health department is following a 34-year-old male who has reported several weeks of general malaise and a low-grade fever. The nurse assigned to his case communicates with the patient regarding the results of his laboratory testing.

64) An ELISA test sent for HIV screening came back with a positive result. The nurse educates the patient that this test is highly sensitive with low specificity. Which of the following statements by the patient demonstrates understanding of this teaching?

A) It is possible that this is a false-positive result since the test may have been positive for something other than HIV.

B) It is unlikely that this is a false-positive result since the test is so specific it does not miss a positive result.

C) It is possible that this is a false-positive result since low specificity means the tests are less accurate.

D) It is unlikely that this is a false-positive result since it is highly sensitive.

65) The patient reports that he had a negative HIV PCR test about a month ago. What is the most appropriate interpretation of this information by the nurse? 

A) PCRs are rarely accurate.

B) The ELISA was a false-positive.

C) It is possible the ELISA was a false-positive, and the Western blot must be performed to confirm the results.

D) The HIV PCR is outdated and does not pick up modern strains of the virus.

66) A Western blot test will be performed. The nurse educates the patient that the Western blot test has high sensitivity and specificity. Which of the following statements by the patient demonstrates understanding of this teaching?

A) A positive Western blot test may be a false-positive since the test has high specificity and may detect the presence of many antibodies.

B) The Western blot test is unlikely to generate a false-positive result. This will be used to confirm or refute the ELISA test results.

C) A positive Western blot may be a false-positive since the test has high sensitivity and may detect the presence of many antibodies.

D) The Western blot test may generate a false-positive result. A positive test will be confirmed by an HIV PCR.

NCLEX Prep - Test Bank Question:  Please read the clinical scenario, and then answer the questions that follow to become familiar with the traditional NCLEX question format.

A 16-year-old male with a low-grade fever, and large and painful red sores around his lips is being evaluated at a pediatric clinic. He has a PCR test pending that was swabbed from the sores, as well as a blood culture with Gram stain, and nasopharyngeal specimen for microscopic examination.

67) Which of the following can be determined from phenotypic assessment of the nasopharyngeal sample? 

A) Cellular shape, size, and arrangement

B) The organism's DNA

C) The presence of antibodies

D) The organism's RNA

68) What kind of data will the PCR results provide? 

A) Biochemical characteristics

B) Immunologic information

C) Genotypic information

D) Microscopic morphology

69) Analysis of the laboratory samples yield a diagnosis of herpes simplex virus. The patient's mother is upset, as she does not believe her son is sexually active. The nurse explains that the presence of HSV does not imply sexual contact and provides education about the accuracy of the results. Which of the following is the best rationale for confidence in the diagnosis?

A) Signs and symptoms are diagnostic.

B) PCR tests are highly sensitive and specific.

C) The Gram stain is an excellent screen for HSV.

D) HSV can be definitively identified by light microscopy.