Unit 4 Questions

All of the following could be virulence factors except:

• Fimbriae

• Capsule

• Cell membrane

• Flagella

• Toxin

• Cell membrane

A-E all contribute to a pathogen’s ability to penetrate and/or hide from a host’s defenses except:

• Invasins

• Capsule

• antigenic variation (phase variation)

• hyaluronidase

• coagulases

• There are no exceptions, A-E are all correct

• There are no exceptions, A-E are all correct

Which of the following virulence factors among A-E is correctly matched with its definition or characterization?

• Invasins: prevents opsonization of pathogen

• Transcytosis: mechanism by which a pathogen might pass through tissues

• OPA protein or M protein: type of exotoxins

• Hyaluronidase or coagulase: used for attachment to cells, a type of adhesin

• All are correctly mathced

• Transcytosis: mechanism by which a pathogen might pass through tissues

If a vaccine to a specific viral disease only a viral envelope protein, this would be called

• A live attenuated vaccine

• a nucleic acid vaccine

• a recombinant vector vaccine

• a subunit vaccine

• an inactivated killed vaccine

• a conjugated vaccine

• none of the above

• a subunit vaccine

If a vaccine contained an avirulent form of a whole virus, capable of replicating, this would be called

• a live attenuated vaccine

• a nucleic acid vaccine

• a recombinant vector vaccine

• a subunit vaccine

• an inactivated killed vaccine

• a conjugated vaccine

• possibly two of the above

• a live attenuated vaccine

The most selective antimicrobial activity would be exhibited by a drug that

• inhibits cell wall synthesis

• inhibits protein synthesis

• injures the plasma membrane

• inhibits nucleic acid synthesis

• all of the above

• inhibits cell wall synthesis

All of the following are modes of action of antiviral drugs except

• inhibition of protein synthesis

• inhibition of DNA synthesis

• inhibition of RNA synthesis

• inhibition of uncoating

• All of the above are modes of action of antiviral drugs

• inhibition of protein synthesis

Within a few weeks of treatment with teh drug 3TC, a patient’s HIV population consists entirely of 3TC-resistant viruses. How can this result best be explained

• The drug caused the HIV RNA genome to change

• A few drug resistant viruses were present at the start of treatment and natural selection increased their frequency

• HIV began making drug resistant versions of reverse transcriptase (a viral enzyme) in response to the drug

• A few drug resistant viruses were present at the start of treatment and natural selection increased their frequency

Which among A-F is incorrect?

• Streptococcus pathogen: necrotizing fasciitis

• Staphylococcus pathogen: boils

• Streptococcus pathogen: strep throat

• Staphylococcus pathogen: scalded skin syndrome

• Streptococcus pathogen: shingles

• Staphylococcus pathogen: folliculitis & impetigo

• A-F are all correct

• Streptococcus pathogen: shingles

All of these typically could potentially cause meningitis EXCEPT

• Listeria monocytogenes

• Neisseria meningitidis

• Streptococcus pneumoniae

• Rabies virus

• All of these can cause meningitis

• Rabies virus

Regarding the pathogen presented thus far, what would be the reservoir of those microbes

• Soil

• Water

• Humans

• Animals

• None of the above

This person is suffering from

• A bad back

• Meningitis

• Botulism

• Listeriosis

• Tetanus

• Tetanus

Humans most frequently contract rabies from the bite of a

• Rat

• Cat

• Bat

• Dog

• Other

• Bat

Which of A-F is not correctly matched?

• Infectious disease initially appears in one form, then years later can assume a different form: Herpes-Zoster virus

• Intracellular foodborne pathogen that can grow at 4ºC: Listeria monocytogenes

• Toxin blocks ability of muscles to contract: Botulism

• Gram-negative diplococci able to cross the blood-brain barrier: Neisseria sp.

• Lesser virulent member of this group of Gram-positive cocci arranged in grape-like cluster: Staphylococcus epidermidis

• Vaccine can be given for treatment following infection: rabies

• A-F are all correctly matched

• A-F are all correctly matched

Most respiratory infections and gastrointestinal infections are _____ in nature

• Bacterial

• Fungal

• Protozoal

• Viral

• Viral

Which of A-F is not correctly matched?

• Pneumonic form of the disease caused by this pathogen is the most contagious: Yersinia pestis

• Common protozoal pathogen causing GI tract infections: Giardia lamblia

• One of its toxins kills ciliated cells in the trachea: Treponema pallidum

• Facultative intracellular foodborne pathogen: Salmonella enteritidis

• Can be the cause of pneumonia and meningitis: Streptococcus pneumonia

• In nature, often found in amoebas: Legionella peumophila

• A-F are all correctly matched

• One of its toxins kills ciliated cells in the trachea: Treponema pallidum

Which of A-E is not considered an obligate or facultative type of intracellular pathogen?

• Legionella pneumophila

• Listeria monocytogenes

• Rabies virus

• Enteroinvasive E. coli (EIEC)

• Neisseria meningitidis

• All are considered either obligate or facultative type of intracellular pathogen

• All are considered either obligate or facultative type of intracellular pathogen

Bacteria

• are totally awesome

• my best friends

• are part of my innate immune system

• are my reason for living

• All the above

• All the above

Which of the following represents a DNA vaccine?

• attenuated measles virus

• a plasmid containing genes for influenza type A protein

• hepatitis B antigen produced in yeast cells

• tetanus toxoid

• a plasmid containing genes for influenza type A protein

The administration of infectious material into the skin as done with smallpox to generate immunity is termed

• variolation

• agglutination

• phagocytosis

• endotoxin effect

• variolation

Which of the following among A-D is false?

• Gram-negative bacteria: possess endotoxin

• Syncytium formation: cytocidal effect of a virus

• Subunit vaccine: contains live, attenuated organisms

• A-B toxins: exotoxins possessing a targeting binding component and a component that disrupts cell function

• None of A-D are false, all are true

• Subunit vaccine: contains live, attenuated organisms

All of the following are modes of action of antiviral drugs except:

• inhibition of adherence to a cell

• inhibition of DNA synthesis

• Inhibition of RNA synthesis

• Inhibition of uncoating

• All of the above are modes of action of antiviral drugs

• All of the above are modes of action of antiviral drugs

Within a few weeks of treatment for herpes virus with the drug isoniazid, a patient’s herpes virus population consists entirely of isoniazid-resistant viruses. How can this be best explained?

• The drug caused the HIV RNA genome to change

• The isoniazid drug spontaneously converted to a form ineffective against the virus

• HIV began making drug-resistant versions of reverse transcriptase (a viral enzyme) in response to the drug

• None of the above

• None of the above

In the presence of penicillin, a cell dies because

• it lacks a cell wall

• it undergoes lysis

• it lacks a cell membrane

• it shrinks

• it undergoes lysis

Which of the following virulence factors among A-D is correctly matched with its definition or characterization?

• Invasins: prevents opsonization of pathogen

• Antigenic variation: allows pathogen to switch between different forms of an extracellular antigen (e.g., flagellum)

• opa protein or M protein: type of exotoxins

• Hyaluronidase or coagulase: used for attachment to cells, a type of adhesin

• All are correctly matched

• Antigenic variation: allows pathogen to switch between different forms of an extracellular antigen (e.g., flagellum)

Superantigen type toxins lead to the release of excessive amounts of _____ stimulating a hyperactive immune response that can lead to shock and death in teh affected individual

• antibodies

• Antigenic variation: allows pathogen to switch between different forms of an extracellular antigen (e.g., flagellum)

• water

• antigen

• interferon

• cytokines

All of the following contribute to a pathogen’s ability to penetrate host defenses or hide from host defenses EXCEPT:

• toxins

• capsules

• antigenic variation

• hyaluronidase

• coagulases

• toxins

M protein, hyaluronidase, collagenase, and often a capsule, can be virulence factors for certain pathogenic strains of

• Listeria

• Streptococcus

• Neisseria

• Staphylococcus

• Yersinia

• Streptococcus

Respiratory pathogen characterized by pseudomembrane formation in the pharynx and toxin production

• Bordetella pertussis

• Streptococcus pneumoniae

• Corynebacterium diphtheriae

• Streptococcus pyogenes

• Legionella pneumonia

• Corynebacterium diphtheriae

Which of the following virulence factors among A-D is correctly matched with its definition or characterization?

• Invasins: prevents opsonization of pathogen

• Antigenic variation: allows pathogen to switch between different forms of an extracellular antigen (e.g., flagellum)

• Opa protein or M protein: type of exotoxins

• Hyaluronidase or coagulase: used for attachment to cells, a type of adhesin

• All are correctly matched

• Antigenic variation: allows pathogen to switch between different forms of an extracellular antigen (e.g., flagellum)

Which pathogen description pair among A-E is incorrectly matched?

• Treponema pallidum: can become a latent infection that later results in shingles

• Staphylococcus aureus: some strains form exotoxins that cause gastroenteritis

• Streptococcus mutans: Gram-positive, alpha-hemolytic pathogen that can cause cavities in your teeth

• Streptococcus pneumoniae: primary cause of bacterial pneumonia among humans

• Yersinia pestis: vector borne disease that causes a sytemic infection

• A-E are all correctly matched

• Treponema pallidum: can become a latent infection that later results in shingles

Which is false among A-C regarding sexually transmitted diseases (STDs)?

• Treponema pallidum: causative agent of syphilis

• Since STD pathogens are susceptible to drying out, they require direct contact with mucous membranes for transmission

• Tertiary syphilis: presence of chancres at site of infection caontaining pathogen

• None of A-C are false; all are true statement

• Tertiary syphilis: presence of chancres at site of infection caontaining pathogen

Which of A-F is not correctly matched?

• More likely to cause GI tract upset than any other microbe: virus, e.g., rotavirus

• Spirochete-causing STD: Treponema pallidum

• Intracellular foodborne pathogen that can cause meningitis: Listeria monocytogenes

• Gram-negative vector borne pathogen that is at its most contagious if it enters the lungs: Yersinia pestis

• This Gram positive causes GI problems without being in your gut: Staphylococcus aureus

• An intracellular pathogen; disease outbreaks associated with contaminated water used for commercial AC ventilation systems: Legionella

• A-F are all correctly matched

• A-F are all correctly matched

All of the following are modes of action of antiviral drugs except

• inhibition of protein synthesis at 70s ribosomes

• inhibition of DNA synthesis

• inhibition of RNA synthesis

• inhibition of uncoating

• All of the above are modes of action of antiviral drugs

• inhibition of protein synthesis at 70s ribosomes

For which diseases listed below does the pathogen responsible have to cross the blood-brain barrier in order to produce the disease?

• Necrotizing fasciitis

• meningococcal meningitis

• dysentery

• tetanus

• plague

• meningococcal meningitis

For which disease listed below might treatment include vaccination after the individual has already acquired the pathogen; this is possible due to the slow nature of growth of the agent and the resulting slow progress of the disease.

• Necrotizing fasciitis

• meningococcal meningitis

• rabies

• tetanus

• plague

• rabies

Superantigen type toxins lead to the release of excessive amounts of _______ stimulating a hyperactive immune response that can lead to shock and death in the affected individual.

• antibodies

• cytokines

• water

• antigen

• interferon

• cytokines

In the presence of penicillin, a cell dies because

• it lacks a cell wall

• it undergoes lysis

• it lacks a cell membrane

• it shrinks

• it undergoes lysis

Within a few weeks of treatment with the drug 3TC, a patient’s HIV population consists entirely of 3TC-resistant viruses. How can this result best be explained?

• The drug caused the HIV RNA genome to change

• A few drug-resistant viruses were present at the start of treatment and natural selection increased their frequency

• HIV began making drug-resistant versions of reverse transcriptase (a viral enzyme) in response to the drug

• None of the above

• A few drug-resistant viruses were present at the start of treatment and natural selection increased their frequency

Which of the following represents a toxoid vaccine?

• attenuated measles virus

• a plasmid containing genes for influenza type A protein

• hepatitis B antigen produced in yeast cells

• tetanus vaccine

• tetanus vaccine

If a vaccine to a specific viral disease contained only a virus envelope protein, this would be called

• a live attenuated vaccine

• a nucleic acid vaccine

• a recombinant vector vaccine

• a subunit vaccine

• a conjugated vaccine

• an inactivated killed vaccine

• a subunit vaccine

Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because

• bacteria from other animals replace those killed by the antibiotics

• the few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on their progeny

• teh antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics

• the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal

• the antibiotics persist in soil and water

• the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal

All of the following contribute to a pathogen’s ability to penetrate host defenses or hide from host defenses, EXCEPT

• toxins

• capsules

• antigenic variation

• hyaluronidase

• coagulases

• toxins

For which disease, or diseases, are humans the primary reservoirs?

• plague

• tetanus

• meningitis

• listeriosis

• none of the above

• meningitis

The group contains pathogens that can be differentiated by reactions observed on blood agar

• Staphylococcus

• Listeria

• Streptococcus

• Neisseria

• E coli

• Streptococcus

Botulism differs from tetanus in that

• botulism causes flaccid paralysis and tetanus causes spastic paralysis

• tetanus is a food-borne disease and botulism is airborne

• botulism is due to an exotoxin and tetanus is due to an endotoxin

• botulism toxin acts directly on muscle cells

• two of the above are correct

• botulism causes flaccid paralysis and tetanus causes spastic paralysis

The gram stain would not be an effective tool to assist in the identification of this pathogen

• Listeria monocytogenes

• Giardia lamblia

• Yersinia pestis

• Clostridium tetani

• Shigella dysenteriae

• The identification of all the above can be aided by performing a Gram stain

• Giardia lamblia

The presence of Gram-negative diplococci in cerebrospinal fluid is generally diagnostic for

• gonorrhea

• tetanus

• meningococcal meningitis

• syphilis

• listeriosis

• meningococcal meningitis

Which characteristic or feature among A-D is not applicable to the listeriosis pathogen

• capable of multiplying within a cell

• ability to grow at 4ºC

• polymerization of actin for cellular movement

• is widespread in soil, water, animals

• all are applicable

• all are applicable

Botulism toxin, tetanus toxin, and vibrio enterotoxin are all examples of

• endotoxin

• exotoxin

• A-B type toxins

• membrane-disrupting toxins

• two of the above are correct

• two of the above are correct

Endotoxins

caused by gram-negatives

Exotoxins

• Cell membrane disruptors

• protein synthesis disrupters

• second messenger pathway disrupters

• superantigen

• proteases

Adhesins

• Fimbriae/pili; glycoproteins

• M protein; Opa protein

Intracellular pathogens

• Invade host cell → invasins; membrane ruffling of host cell; actin rockets

• Ingestion via phagosome → break out; survive in phagolysosome; prevent fusion w/ lysosome

Extracellular pathogens

• Capsule

• Bind/degrade antibodies → Proteins A (Staph); IgA protease (Neisseria)

• Bind complement → M protein (Strep)

• Phase variation