©BRIGHTSTARS EXAM SOLUTIONS
11/16/2024 10:16 AM
MMG 301 Exam Questions With Correct
Answers
What are the typical sources of specimens? - answer✔•Blood - look for bacteremia or
viremia•Can also test blood for the presence of antibodies to a pathogen.
•Urine - bacteriuria - presence of bacteria in urine; most often detected using urinalysis dipstick
or growth-dependent methods.
•Feces - look for intestinal pathogens (bacteria or eukaryotes).•Abscesses and wounds - swab
or needle aspiration.•Throat/nasal swabs - soft cotton swabs to collect samples to test for
bacteria or viruses. •Genital samples - to get specimens to test for sexually transmitted
pathogens.
Be able to state the medical terms of bacteria in the blood and urine. - answer✔Bacteria in
Blood:Bacteremia or Viremia Bacteria in Urine: Bacteriuria
Know the Biosafety levels for laboratories working with pathogens. - answer✔4 classifications
based on levels of risk; higher numbers for more dangerous pathogens.
● BSL1: Few safety controls; open lab bench; non-pathogenic organisms; limited access.
● BSL 2: Can have an open bench, but gloves, lab coat, eye protection required; used for
moderate pathogens.
● BSL 3: Designed for pathogens; organisms manipulated in biological safety cabinets;
room under slight negative pressure; extensive filtration of air.
● BSL 4: Used for life-threatening pathogens that can be transmitted by aerosols;
pressurized suits for workers; Ebola, Marburg viruses.
Be able to discern the difference between differential and selective media. - answer✔Selective
Medium: Contains substances that inhibit growth of certain types of bacteria. Differential
Medium: Includes compounds that allows visualization of certain biochemical pathways and
products.
1|Page
, ©BRIGHTSTARS EXAM SOLUTIONS
11/16/2024 10:16 AM
Describe the three common methods used to test sensitivity of a pathogen to an antibiotic. -
answer✔Minimum inhibitory concentration (MIC): Using tube dilution assay.
Disk diffusion assay: Pure culture is spread on plate; then disks containing different
antibiotics are placed on plate. Also called a Kirby-Bauer test.
"Etest": MIC is read from the edge of the clear zone using the scale on the strips.
Define an antibody titer and how it changes during the course of an infectious disease. -
answer✔Antibody titer: The lowest concentration of serum at which an antibody-antigen
reaction is observed.
How is a Mantoux skin test performed and how is it interpreted? - answer✔Performed:
Locate and clean the injection site. 2-4 inches below the elbow joint. Place forearm palm
side up on firm, well-lit surface. Select an area free of barriers (ex: scars / sores) to
placing and reading. Clean the area with an alcohol swab.
Check expiration date on vial and ensure that the vial contains tuberculin (5 TU per
0.1ml). Use a single-dose tuberculin syringe with a 1⁄4 - 1⁄2 inch, 27 gauge needle with a
short bevel. Fill the syringe with 0.1 ml of tuberculin.
Insert slowly, bevel up, at a 5-15 degree angle. Needle bevel can be seen just below the
skin surface. After injection, a tense pale wheal should appear over the needle.
Wheal should be 6-10 mm in diameter. If not, repeat test as a site at least 2 inches away
from the original site.
Record information.
Interpreted:
● Based on the size of induration dependent upon the test run. Famous is TB test.
Define serology. - answer✔The use of antigen-antibody reactions to detect: ● Antigens
● Antibodies● For a few pathogens, previous exposure can be detected by an inflammatory
response
to injection of a purified antigen under the skin.
2|Page
, ©BRIGHTSTARS EXAM SOLUTIONS
11/16/2024 10:16 AM
Describe what an epitope is. - answer✔The part of an antigen molecule to which an antibody
attaches itself.
Understand how agglutination assays are used to detect antibodies or antigens from a patient. -
answer✔Agglutination reactions use antigens that are attached to large particles or whole cells
to produce visible clumping and aggregation.Performed in tubes or on slides.
Agglutination: Soluble antibodies cause clumping of antigens that are on the surface of a
synthetic particle or cell. TypicallyAgglutination of bacterial cells (serotyping)
Agglutination reactions use antigens that are attached to large particles or whole cells to
produce visible clumping and aggregation.
Agglutination using synthetic latex beads coated with antibodies to a protein found on the
surface of Staphylococcus aureus cells.
Understand direct and indirect EIA. - answer✔Enzyme Immunosorbent Assays (EIA)
Direct: Immunoassays are immobilized antibody to test for an antigen from the patient.
Indirect: Use immobilized antigen to detect antibodies from a patient.
Know how PCR can be used to identify pathogen DNA in a patient. - answer✔•Strategy: provide
diagnostic primers into a PCR reaction that will give a specific PCR double-stranded DNA
product only if there is pathogen DNA (template DNA) in the patient sample.
Briefly describe what qPCR is and how it works. - answer✔qPCR quantitative real-time PCR.
Requires:
● A PCR thermocycler that includes fluorescence measurements capabilities of each
individual reaction.
● A fluorescent probe that is included in the reaction.
○ Fluorescence increases as double-stranded DNA product is made.● RNA from pathogens can
be detected by first performing a reverse-transcriptase
reaction to convert RNA to DNA
Understand that different serotypes of a particular pathogen can have different antibiotic
susceptibilities and be able to explain how different strains arise. - answer✔Types of genome
alterations:
3|Page
11/16/2024 10:16 AM
MMG 301 Exam Questions With Correct
Answers
What are the typical sources of specimens? - answer✔•Blood - look for bacteremia or
viremia•Can also test blood for the presence of antibodies to a pathogen.
•Urine - bacteriuria - presence of bacteria in urine; most often detected using urinalysis dipstick
or growth-dependent methods.
•Feces - look for intestinal pathogens (bacteria or eukaryotes).•Abscesses and wounds - swab
or needle aspiration.•Throat/nasal swabs - soft cotton swabs to collect samples to test for
bacteria or viruses. •Genital samples - to get specimens to test for sexually transmitted
pathogens.
Be able to state the medical terms of bacteria in the blood and urine. - answer✔Bacteria in
Blood:Bacteremia or Viremia Bacteria in Urine: Bacteriuria
Know the Biosafety levels for laboratories working with pathogens. - answer✔4 classifications
based on levels of risk; higher numbers for more dangerous pathogens.
● BSL1: Few safety controls; open lab bench; non-pathogenic organisms; limited access.
● BSL 2: Can have an open bench, but gloves, lab coat, eye protection required; used for
moderate pathogens.
● BSL 3: Designed for pathogens; organisms manipulated in biological safety cabinets;
room under slight negative pressure; extensive filtration of air.
● BSL 4: Used for life-threatening pathogens that can be transmitted by aerosols;
pressurized suits for workers; Ebola, Marburg viruses.
Be able to discern the difference between differential and selective media. - answer✔Selective
Medium: Contains substances that inhibit growth of certain types of bacteria. Differential
Medium: Includes compounds that allows visualization of certain biochemical pathways and
products.
1|Page
, ©BRIGHTSTARS EXAM SOLUTIONS
11/16/2024 10:16 AM
Describe the three common methods used to test sensitivity of a pathogen to an antibiotic. -
answer✔Minimum inhibitory concentration (MIC): Using tube dilution assay.
Disk diffusion assay: Pure culture is spread on plate; then disks containing different
antibiotics are placed on plate. Also called a Kirby-Bauer test.
"Etest": MIC is read from the edge of the clear zone using the scale on the strips.
Define an antibody titer and how it changes during the course of an infectious disease. -
answer✔Antibody titer: The lowest concentration of serum at which an antibody-antigen
reaction is observed.
How is a Mantoux skin test performed and how is it interpreted? - answer✔Performed:
Locate and clean the injection site. 2-4 inches below the elbow joint. Place forearm palm
side up on firm, well-lit surface. Select an area free of barriers (ex: scars / sores) to
placing and reading. Clean the area with an alcohol swab.
Check expiration date on vial and ensure that the vial contains tuberculin (5 TU per
0.1ml). Use a single-dose tuberculin syringe with a 1⁄4 - 1⁄2 inch, 27 gauge needle with a
short bevel. Fill the syringe with 0.1 ml of tuberculin.
Insert slowly, bevel up, at a 5-15 degree angle. Needle bevel can be seen just below the
skin surface. After injection, a tense pale wheal should appear over the needle.
Wheal should be 6-10 mm in diameter. If not, repeat test as a site at least 2 inches away
from the original site.
Record information.
Interpreted:
● Based on the size of induration dependent upon the test run. Famous is TB test.
Define serology. - answer✔The use of antigen-antibody reactions to detect: ● Antigens
● Antibodies● For a few pathogens, previous exposure can be detected by an inflammatory
response
to injection of a purified antigen under the skin.
2|Page
, ©BRIGHTSTARS EXAM SOLUTIONS
11/16/2024 10:16 AM
Describe what an epitope is. - answer✔The part of an antigen molecule to which an antibody
attaches itself.
Understand how agglutination assays are used to detect antibodies or antigens from a patient. -
answer✔Agglutination reactions use antigens that are attached to large particles or whole cells
to produce visible clumping and aggregation.Performed in tubes or on slides.
Agglutination: Soluble antibodies cause clumping of antigens that are on the surface of a
synthetic particle or cell. TypicallyAgglutination of bacterial cells (serotyping)
Agglutination reactions use antigens that are attached to large particles or whole cells to
produce visible clumping and aggregation.
Agglutination using synthetic latex beads coated with antibodies to a protein found on the
surface of Staphylococcus aureus cells.
Understand direct and indirect EIA. - answer✔Enzyme Immunosorbent Assays (EIA)
Direct: Immunoassays are immobilized antibody to test for an antigen from the patient.
Indirect: Use immobilized antigen to detect antibodies from a patient.
Know how PCR can be used to identify pathogen DNA in a patient. - answer✔•Strategy: provide
diagnostic primers into a PCR reaction that will give a specific PCR double-stranded DNA
product only if there is pathogen DNA (template DNA) in the patient sample.
Briefly describe what qPCR is and how it works. - answer✔qPCR quantitative real-time PCR.
Requires:
● A PCR thermocycler that includes fluorescence measurements capabilities of each
individual reaction.
● A fluorescent probe that is included in the reaction.
○ Fluorescence increases as double-stranded DNA product is made.● RNA from pathogens can
be detected by first performing a reverse-transcriptase
reaction to convert RNA to DNA
Understand that different serotypes of a particular pathogen can have different antibiotic
susceptibilities and be able to explain how different strains arise. - answer✔Types of genome
alterations:
3|Page
