MSU MMG 301 Final Exam questions
with 100% correct answers 2025/2026
How are clinical samples obtained? - correct answer ✔✔With a swab, syringe, or sputum (spit)
sample.
Where are clinical samples taken from? - correct answer ✔✔Blood, urine, feces,
abscesses/wounds, genitals, throat/mouth
Define: Bacteremia - correct answer ✔✔bacterial infection of the blood
Define: Bacteriuria - correct answer ✔✔bacteria in the urine
Define: Biosafety Level 1 (BSL-1) - correct answer ✔✔non-pathogenic organisms, few safety
controls
Define: Biosafety Level 2 (BSL-2) - correct answer ✔✔Moderate pathogens (e. coli), need to
wear safety equipment (gloves, lab coat, goggles)
Define: Biosafety Level 3 (BSL-3) - correct answer ✔✔Harmful pathogens, organisms
manipulated in "safety cabinets", under negative pressure with extensive filtration
Define: Biosafety Level 4 (BSL-4) - correct answer ✔✔Life-threatening pathogens that can be
transmitted through the air (ebola). Workers wear pressurized suits connected to a constant air
flow.
,Define: Selective media - correct answer ✔✔Contains substances that inhibit the growth of
unwanted bacteria (antibiotics).
Define: Differential media - correct answer ✔✔Includes compounds that allow for visualization
of certain biochemical pathways and products (pH will change color of organisms)
Methods used to determine a pathogens sensitivity to antibiotics - correct answer ✔✔-
Minimum inhibitory concentration (MIC)
-Disk diffusion assay
-Etest
Minimum inhibitory concentration (MIC) - correct answer ✔✔Tube dilution, with each tube
holding a different concentration of antibiotics in increasing order. Turbidity in the tubes shows
bacterial growth. Tubes that are clear are at higher concentrations of antibiotics.
Disk diffusion assay - correct answer ✔✔A pure culture is spread on plate; then disks containing
different antibiotics are placed on plate
What are the steps in disk diffusion method (Kirby-Bauer test)? - correct answer ✔✔-Test
organism is spread on agar culture medium.
-Sterile antibiotic discs are applied to the surface of the medium.
-Incubate for 24-48 hours
-Zones of inhibition will have formed around the disks containing chemicals or antibiotics the
organism is sensitive to.
Etest - correct answer ✔✔A strip containing different concentrations of antibiotics is placed on
a plate with a pure culture. A mix between the MIC and disk diffusion tests.
,How are the fundamental features of antibodies used for diagnostic purposes? - correct answer
✔✔Antibodies will have a highly specific reaction with their cognate antigens. This reaction will
allow for the detection of antigens in complex mixtures, such as blood, urine, semen, etc.
Describe serotypes of a pathogen in regards to antigens. - correct answer ✔✔Different
serotypes of a pathogen use different antigens on their cellular surface and will have different
antigenic properties.
Describe an example of antigenic differences of serotypes - correct answer ✔✔The pathogen E.
coli has 181 serotypes for LPS, and 57 for Flagella. Those different serotypes will now have those
distinct properties. (Specific example: O157H7)
Define: Antibody titer - correct answer ✔✔-The lowest concentration of serum at which an
antibody-antigen reaction is observed.
-The amount of antibodies being created against a particular antigen.
How does an antibody titer change over the course of an infectious disease? - correct answer
✔✔The antibody (AB) count start off very low, but rises as the infection develops until the
immune system is able to fight off the infection. The AB levels with then slowly drop
What is a Mantoux skin test? - correct answer ✔✔A skin test that is used to determine previous
exposure or current infection of TB (Mycobacterium tuberculosis).
How is a Mantoux skin test performed and how is it interpreted. - correct answer ✔✔A small
amount of purified MTB antigen uner the skin. If the area is red and swolen (an inflammatory
response) then the person is currently or previously been exposed to TB.
Define: Serology - correct answer ✔✔The identification and examination of different antibodies
in blood serum.
, Define: Epitope - correct answer ✔✔The part of an antigen molecule (protein) to which an
antibody attaches itself
How are agglutination assays used to detect antibodies or antigens from a patient. - correct
answer ✔✔Soluble antibodies are added to different samples and there is clumping in the
sample, the antigen to that antibody is present in the sample.
Define: Direct Enzyme Immunosorbent Assays (EIA) - correct answer ✔✔Direct immunoassays
use immobilized antibodies to test for an antigen from a patient.
Define: Indirect Enzyme Immunosorbent Assays (EIA) - correct answer ✔✔Indirect
immunoassays use immobilized antigens to detect antibodies from a patient.
How can PCR be used to identify pathogen DNA in a patient? - correct answer ✔✔Specific DNA
primers added to a PCR reaction means that a double-stranded DNA product will only be made
if the PCR primer sequences are able exactly base pair with pathogen DNA.
Define: Quantitative real-time PCR (qPCR) - correct answer ✔✔qPCR is a way to detect PCR
products using a fluorescent probe in the PCR reaction. The more of double-stranded product
made will increase fluorescence which can be measured with a PCR thermocycler
How do differences in antibiotic susceptibility arise in different serotypes of a pathogen? -
correct answer ✔✔Different serotypes can have different genome organization/structure that
arise from:
-Genome rearrangements
-Mobile genetic elements (plasmids)
-Phage Integrations
-Pathogenicity Islands
with 100% correct answers 2025/2026
How are clinical samples obtained? - correct answer ✔✔With a swab, syringe, or sputum (spit)
sample.
Where are clinical samples taken from? - correct answer ✔✔Blood, urine, feces,
abscesses/wounds, genitals, throat/mouth
Define: Bacteremia - correct answer ✔✔bacterial infection of the blood
Define: Bacteriuria - correct answer ✔✔bacteria in the urine
Define: Biosafety Level 1 (BSL-1) - correct answer ✔✔non-pathogenic organisms, few safety
controls
Define: Biosafety Level 2 (BSL-2) - correct answer ✔✔Moderate pathogens (e. coli), need to
wear safety equipment (gloves, lab coat, goggles)
Define: Biosafety Level 3 (BSL-3) - correct answer ✔✔Harmful pathogens, organisms
manipulated in "safety cabinets", under negative pressure with extensive filtration
Define: Biosafety Level 4 (BSL-4) - correct answer ✔✔Life-threatening pathogens that can be
transmitted through the air (ebola). Workers wear pressurized suits connected to a constant air
flow.
,Define: Selective media - correct answer ✔✔Contains substances that inhibit the growth of
unwanted bacteria (antibiotics).
Define: Differential media - correct answer ✔✔Includes compounds that allow for visualization
of certain biochemical pathways and products (pH will change color of organisms)
Methods used to determine a pathogens sensitivity to antibiotics - correct answer ✔✔-
Minimum inhibitory concentration (MIC)
-Disk diffusion assay
-Etest
Minimum inhibitory concentration (MIC) - correct answer ✔✔Tube dilution, with each tube
holding a different concentration of antibiotics in increasing order. Turbidity in the tubes shows
bacterial growth. Tubes that are clear are at higher concentrations of antibiotics.
Disk diffusion assay - correct answer ✔✔A pure culture is spread on plate; then disks containing
different antibiotics are placed on plate
What are the steps in disk diffusion method (Kirby-Bauer test)? - correct answer ✔✔-Test
organism is spread on agar culture medium.
-Sterile antibiotic discs are applied to the surface of the medium.
-Incubate for 24-48 hours
-Zones of inhibition will have formed around the disks containing chemicals or antibiotics the
organism is sensitive to.
Etest - correct answer ✔✔A strip containing different concentrations of antibiotics is placed on
a plate with a pure culture. A mix between the MIC and disk diffusion tests.
,How are the fundamental features of antibodies used for diagnostic purposes? - correct answer
✔✔Antibodies will have a highly specific reaction with their cognate antigens. This reaction will
allow for the detection of antigens in complex mixtures, such as blood, urine, semen, etc.
Describe serotypes of a pathogen in regards to antigens. - correct answer ✔✔Different
serotypes of a pathogen use different antigens on their cellular surface and will have different
antigenic properties.
Describe an example of antigenic differences of serotypes - correct answer ✔✔The pathogen E.
coli has 181 serotypes for LPS, and 57 for Flagella. Those different serotypes will now have those
distinct properties. (Specific example: O157H7)
Define: Antibody titer - correct answer ✔✔-The lowest concentration of serum at which an
antibody-antigen reaction is observed.
-The amount of antibodies being created against a particular antigen.
How does an antibody titer change over the course of an infectious disease? - correct answer
✔✔The antibody (AB) count start off very low, but rises as the infection develops until the
immune system is able to fight off the infection. The AB levels with then slowly drop
What is a Mantoux skin test? - correct answer ✔✔A skin test that is used to determine previous
exposure or current infection of TB (Mycobacterium tuberculosis).
How is a Mantoux skin test performed and how is it interpreted. - correct answer ✔✔A small
amount of purified MTB antigen uner the skin. If the area is red and swolen (an inflammatory
response) then the person is currently or previously been exposed to TB.
Define: Serology - correct answer ✔✔The identification and examination of different antibodies
in blood serum.
, Define: Epitope - correct answer ✔✔The part of an antigen molecule (protein) to which an
antibody attaches itself
How are agglutination assays used to detect antibodies or antigens from a patient. - correct
answer ✔✔Soluble antibodies are added to different samples and there is clumping in the
sample, the antigen to that antibody is present in the sample.
Define: Direct Enzyme Immunosorbent Assays (EIA) - correct answer ✔✔Direct immunoassays
use immobilized antibodies to test for an antigen from a patient.
Define: Indirect Enzyme Immunosorbent Assays (EIA) - correct answer ✔✔Indirect
immunoassays use immobilized antigens to detect antibodies from a patient.
How can PCR be used to identify pathogen DNA in a patient? - correct answer ✔✔Specific DNA
primers added to a PCR reaction means that a double-stranded DNA product will only be made
if the PCR primer sequences are able exactly base pair with pathogen DNA.
Define: Quantitative real-time PCR (qPCR) - correct answer ✔✔qPCR is a way to detect PCR
products using a fluorescent probe in the PCR reaction. The more of double-stranded product
made will increase fluorescence which can be measured with a PCR thermocycler
How do differences in antibiotic susceptibility arise in different serotypes of a pathogen? -
correct answer ✔✔Different serotypes can have different genome organization/structure that
arise from:
-Genome rearrangements
-Mobile genetic elements (plasmids)
-Phage Integrations
-Pathogenicity Islands
