Laboratories that work with moderate risk pathogens are classified as
A) BSL-1.
B) BSL-2.
C) BSL-3.
D) BSL-4.
2) Bacteremia is a term used
A) to
... [Show More] indicate the presence of bacteria in the blood.
B) synonymously with septicemia.
C) when the same organism is isolated from more than one site.
D) to indicate the presence of bacteria in the lungs.
3) Which of the following must be accomplished FIRST in order to conduct RT-PCR?
A) Complementary DNA must be synthesized from double-stranded DNA.
B) Complementary DNA must be synthesized from RNA.
C) Complementary DNA must be synthesized from proteins.
D) Complementary DNA must be synthesized from single-stranded DNA.
4) The most common of all nosocomial infections are ________ infections.
A) blood
B) reproductive tract
C) urinary tract
D) respiratory tract
5) MacConkey agar and eosin-methylene blue (EMB) agar are ________ media.
A) selective but not differential
B) differential but not selective
C) both selective and differential
D) neither selective nor differential
6) An Etest® is a clinical tool used for the determination of
A) enteric presence.
B) Escherichia coli O157:H7 presence.
C) the minimum inhibitory concentration (MIC) value of an antimicrobial agent.
D) pathogenic enzyme activity.
7) The component that enriches chocolate agar is
A) chocolate.
B) methyl brown indicator dye.
C) heat-lysed blood cells.
D) None of the answers are correct.
8) Modified Thayer-Martin (MTM) agar
A) incorporates antibiotics into the medium.
B) enhances the growth of normal flora.
C) prevents the growth of Neisseria gonorrhoeae, but promotes the growth of Neisseria meningitidis.
D) prevents the growth of Neisseria meningitides, but promotes the growth of Neisseria gonorrhoeae.
9) The oxygen-free gas commonly employed during anoxic incubation of a bacterial culture is a mixture of
A) nitrogen and carbon dioxide.
B) nitrogen and carbon monoxide.
C) nitrogen and argon.
D) nitrogen and hydrogen.
10) Which type of medium typically contains an indicator dye?
A) selective but not differential
B) differential but not selective
C) both selective and differential
D) neither selective nor differential
11) Some antibiotics inhibit protein synthesis by disruption of translation through interactions with the
A) ribosome.
B) protein.
C) DNA.
D) chromosome.
12) The disk-diffusion test is used for
A) assessing antimicrobial activity.
B) the identification of Escherichia coli.
C) the identification of viral plaques.
D) the detection of antigen.
13) Which of the following immunological tests would allow the specific identification of a microorganism directly in a patient specimen?
A) fluorescent antibody (FA)
B) radioimmunoassay (RIA)
C) enzyme-linked immunosorbent assay (EIA)
D) agglutination
14) EMB agar preferentially selects for the growth of ________ bacteria.
A) gram-positive
B) gram-negative
C) gram-variable
D) both gram-positive and gram-negative
15) Latex bead agglutination tests are
A) rapid and reliable tests used for the detection of certain bacteria as well as certain serum antibodies.
B) inferior tests used in developing countries not having facilities for more reliable assays.
C) an integral part of the EIA test procedure.
D) too expensive for routine use.
16) The first antibiotic to be characterized was a
A) cephalosporin.
B) quinolone.
C) β-lactam.
D) macrolide.
17) One advantage of the fluorescent antibodies that permits disease diagnosis long before primary isolation techniques yield results is that
A) cross-reactions do not occur.
B) few controls are required.
C) nonspecific staining does not occur.
D) it may be applied directly to tissue.
18) Which of the following is a mechanism of aminoglycosides?
A) inhibition of cell wall biosynthesis
B) prevention of peptidoglycan crosslinking
C) inhibition of DNA replication
D) targeting the 30S ribosomal subunit
19) Which of the following would be useful for treating Candida?
A) an azole
B) a fusion inhibitor
C) a macrolide
D) a nucleoside reverse transcriptase inhibitor
20) The blotting of proteins from polyacrylamide gels to nitrocellulose paper, and the subsequent identification by specific antibodies, is called a(n) ________ blot.
A) Western
B) Eastern
C) Southern
D) Northern
21) Widespread antimicrobial drug resistance is usually passed by
A) heterologous gene expression.
B) reverse transcription.
C) horizontal gene transfer.
D) gene splicing.
22) Most drug-resistant bacteria isolated from patients contain a(n)
A) R plasmid.
B) T1 phage.
C) reverse transcriptase.
D) β-lactam.
23) Antibody titer can be measured by
A) negative microscopy.
B) agglutination.
C) plate counts done after isolating the pathogen.
D) polymerase chain reaction.
24) Compared with other precipitation tests, agglutination tests are
A) more sensitive.
B) less sensitive.
C) about equally sensitive.
D) highly variable in sensitivity, and thus the sensitivities cannot be compared.
25) Blood agar is an example of a(n) ________ medium.
A) selective
B) general-purpose
C) enrichment
D) differential
26) Common contaminants in blood drawn from a vein include all EXCEPT which of the following?
A) Staphylococcus epidermidis
B) Coryneform bacteria
C) Propionibacteria
D) Escherichia coli
27) Intestinal parasites can be identified by observing stool samples for the presence of
A) cysts.
B) antibodies.
C) LPS.
D) blood.
28) Chocolate agar is an example of a ________ medium.
A) selective
B) general-purpose
C) nonselective enriched
D) differential
29) A laboratory in which Ebola virus is studied would be classified as a BSL-________ laboratory.
A) 1
B) 2
C) 3
D) 4
30) The tuberculin skin test looks to identify ________ specific to Mycobacterium tuberculosis.
A) antibodies
B) antigens
C) delayed hypersensitive (DTH) TH1 cells
D) delayed hypersensitive (DTH) TC cells
31) Which of the following is a cause of drug-specific resistance in disease-causing organisms?
A) inappropriate hygiene
B) nosocomial infection
C) poor immunity
D) indiscriminate nonmedical use of antimicrobials
32) Which of the following is a novel antimicrobial target?
A) disruption of lipid biosynthesis
B) inhibition of protein synthesis
C) inhibition of cell wall biosynthesis
D) inhibition of peptidoglycan crosslinking
33) The basis for blood typing is referred to as
A) neutralization.
B) hemagglutination.
C) immunodiffusion.
D) precipitation.
34) Which bacterium shows a characteristic green sheen when grown on eosin-methylene blue (EMB) agar?
A) Escherichia coli
B) Salmonella enterica
C) Staphylococcus aureus
D) Streptococcus pyogenes
35) Protein A, commonly used in immunoblots, is derived from
A) Staphylococcus.
B) Escherichia.
C) Bacillus.
D) Clostridium.
36) Two common or important bacterial pathogens found in the blood are
A) Pseudomonas aeruginosa and Escherichia coli.
B) Enterobacter and Proteus.
C) Shigella and Salmonella.
D) HIV and Escherichia coli.
37) A gram-negative, oxidase-positive diplococcus growing on chocolate agar likely belongs to the genus
A) Neisseria.
B) Escherichia.
C) Mycobacterium.
D) Pseudomonas.
38) ________, periodic reports on the susceptibility of clinically isolated organisms to the antibiotics in current local use, are particularly valuable for tracking the emergence of new antibiotic-resistant strains of pathogens.
A) Antibiotic susceptibility plates
B) Antibiograms
C) Direct agglutination reports
D) Histograms
39) ________ defines the lowest quantity of an antigen that can be detected in a serological test.
A) Specificity
B) Antigenic capacity
C) Minimal inhibitory concentration
D) Sensitivity
40) Which of the following prevents supercoiling of bacterial DNA?
A) macrolides
B) quinolones
C) penicillins
D) cephalosporins
41) In the United States, every clinical and research institution requires that workers be protected from ________ that is contracted almost exclusively from handling patient specimens (rather than from known exposure or accidents).
A) anthrax
B) hepatitis B
C) drug-resistant mycobacteria
D) influenza
42) The use of selected culture media and incubation conditions to isolate microorganisms from samples is known as a(n)
A) differential culture.
B) selective culture.
C) enrichment culture.
D) sensitive culture.
43) How is drug-resistant Neisseria gonorrhoeae treated?
A) with penicillinase-resistant β-lactams
B) with tetracycline
C) with synthetic analogs of tetracycline
D) with vancomycin
44) An important intestinal pathogen generally acquired from contaminated food or water is
A) Clostridium perfringens.
B) Mycobacterium tuberculosis.
C) Ebola virus.
D) Escherichia coli O157:H7.
45) Obligately anaerobic normal flora are found in ________, which is an/are anoxic habitat(s) of the body.
A) the kidneys
B) the skin
C) portions of the oral cavity
D) the lungs
46) A positive antibody titer indicates
A) previous exposure to an antigen.
B) active infection.
C) latent disease.
D) a healthy individual.
47) Methylene blue in EMB agar is selective for
A) gram-positives.
B) gram-negatives.
C) viral plaques.
D) both gram-positives and gram-negatives.
48) The study of antigen-antibody reactions is known as
A) serology.
B) immunology.
C) toxicology.
D) epidemiology.
49) Indirect EIA is used to detect
A) antigens.
B) antibodies.
C) viruses.
D) serum.
50) Protein A has a strong affinity for
A) antigen.
B) blood.
C) protein.
D) antibody.
51) ________ is used to monitor gene expression of a pathogen.
A) Reverse transcription PCR
B) Serology
C) Antigen capture assay
D) Qualitative PCR
52) Hybridization requires a nucleic acid probe that binds to DNA or RNA of interest, which must be in the ________ form for hybridization to occur.
A) single-stranded
B) double-stranded
C) oligomerized
D) polymerized
53) Which of the following antibiotics inhibits RNA synthesis?
A) penicillin
B) erythromycin
C) rifampin
D) azithromycin
54) A mechanism for penicillin resistance in bacteria is
A) acetylation of the antibiotic.
B) phosphorylation of the antibiotic.
C) confirmation change of the antibiotic.
D) splitting the β-lactam ring of the antibiotic.
55) SYBR Green, commonly used in qPCR, binds nonspecifically to
A) ssDNA
B) dsDNA
C) ssRNA
D) dsRNA
True/False Questions
1) The causal agents of urinary tract diseases are often members of the normal flora.
2) Finding no bacterial growth, despite persistent urinary tract symptoms, indicates that the problem is likely either non-pathogenically physiological or psychosomatic.
3) In cases of suspected foodborne or waterborne infections, fecal samples should be inoculated into a variety of selective media.
4) Hydrogen sulfide production is assayed by growth in a medium containing ferric iron (Fe3+).
5) The EIA test for HIV infection is a direct test for HIV envelope proteins.
6) In the EIA test for HIV infection, the microtiter plate is coated with disrupted HIV particles.
7) MOST microbiology research laboratories maintain BSL-2 standards.
8) Many pathogens can be readily grown in laboratory culture.
9) ALL positive HIV-EIA tests must be confirmed by another independent test, usually the HIV Western blot.
10) Salmonella is commonly associated with wound infections.
11) Gram stain smears of urethral exudates for the detection of Neisseria gonorrhoeae are highly specific.
12) Nucleic acid probes are NOT suitable for the detection of viruses.
13) One problem with the EIA test is the disposal of radioactive wastes.
14) When using the EIA test for HIV screening, BOTH false negative and false positive results are possible.
15) Chitin is found ONLY in fungi and insects.
16) At this time, EIA tests are too difficult for routine diagnoses.
17) Nucleic acid probes and immunological reagents are NOT commonly used in the clinical laboratory for the diagnosis of viral disease, because the cultivation of the virus is often difficult or even impossible.
18) Some infectious agents, such as Neisseria gonorrhoeae, do NOT elicit a systemic immune response.
19) Fluorescent antibodies can be used to separate mixtures of cells into relatively pure populations with a fluorescence cytometer.
20) To detect antibodies in human serum, the direct EIA is most commonly employed.
21) Literally hundreds of clinically useful EIAs have been developed.
22) Interferons promote viral replication.
Essay Questions
1) Use specific examples to describe the difference between a differential and a selective medium.
2) Describe the use of combination drugs and why they are effective. Provide examples.
3) Describe the three main components to PCR-based testing.
4) Propose a series of procedures to determine whether a patient has a urinary tract infection.
5) Describe mechanisms of transfer of healthcare-associated infections (HAIs).
6) Discuss how recent advances in the molecular biology of nucleic acids have revolutionized methods used for the identification of infectious disease agents and how they are favored over traditional biochemical tests.
7) Differentiate between the various biosafety levels and when they are most appropriately used.
8) What is the basis for inferring infection of a pathogen when a serological EIA is performed? In this context, what does a positive result indicate?
9) Discuss antimicrobial susceptibility testing and the use of minimal inhibitory concentration (MIC) values.
10) Explain the principle difference between direct agglutination and passive agglutination.
11) When a fecal sample is collected from an ill patient, how are each of the following identified: bacterial cell, eukaryotic protist, and virus? [Show Less]