Question 1

Descibe two specific nonpili protein adhesins used in pathogenesis.

Accepted Answer

Adhesins are protein structures (often on the cell surface of a viral capsid or envelop), other than pili (fimbrae), used for attachment to the host cell. Specific examples include Bordetella pertussis (the causative agent of whooping cough uses pertactin to attach to the host); Streptococcus protein F (binds to fibronectin); and enteropathogenic Escherichia coli intimin protein (binds to Tir). Viruses also attach to the host using capsid or envelop proteins.

Question 2

Bacteria whose optimum growth temperature is 37°C and that produce copious amounts of polysaccharides and capsules are most likely to be:

Accepted Answer

A)  opportunistic pathogen 
B)  etiologic agent for septicemia 
C)  normal flora 
D)  marine organisms 
E)  probionts 
A)  opportunistic pathogen 
B)  etiologic agent for septicemia 
C)  normal flora 
D)  marine organisms 
E)  probionts B

Question 3

Protein A helps Staphylococcus aureus avoid:

Accepted Answer

A)  antibiotics 
B)  apoptosis 
C)  phagocytosis 
D)  cytotoxic T cells 
E)  phagosome-lysosome fusion 
A)  antibiotics 
B)  apoptosis 
C)  phagocytosis 
D)  cytotoxic T cells 
E)  phagosome-lysosome fusion C

Question 4

The current classification of bacteria pili is based on __________ rather than __________.

Accepted Answer

A)  phenotype; function 
B)  function; amino acid sequence 
C)  protein sequence; phenotype 
D)  origin; protein sequence 
E)  size; phenotype 
A)  phenotype; function 
B)  function; amino acid sequence 
C)  protein sequence; phenotype 
D)  origin; protein sequence 
E)  size; phenotype

Question 5

What do the anthrax, Escherichia coli, cholera, and Bordetella toxins have in common?

Accepted Answer

A)  all inhibit protein synthesis 
B)  all possess ADP ribosyltransferase activity 
C)  all cause diarrhea 
D)  all disrupt the cell membrane 
E)  all trigger apoptosis 
A)  all inhibit protein synthesis 
B)  all possess ADP ribosyltransferase activity 
C)  all cause diarrhea 
D)  all disrupt the cell membrane 
E)  all trigger apoptosis

Question 6

Multivalent adhesion molecule 7, or MAM7, is a unique adhesion because it:

Accepted Answer

A)  is expressed late in an infection 
B)  is found only in Gram-positive organisms 
C)  is important in initiating infection 
D)  decreases the LD50 of an organism 
E)  acts as a toxin 
A)  is expressed late in an infection 
B)  is found only in Gram-positive organisms 
C)  is important in initiating infection 
D)  decreases the LD50 of an organism 
E)  acts as a toxin

Question 7

Which of the following does NOT result from the release of endotoxin from Gram-negative bacteria?

Accepted Answer

A)  fever 
B)  activation of the alternate complement pathway 
C)  vasodilation 
D)  hypertension 
E)  shock 
A)  fever 
B)  activation of the alternate complement pathway 
C)  vasodilation 
D)  hypertension 
E)  shock

Question 8

Which of the following protein secretory systems injects effector molecules directly from the bacterial cytoplasm into the host cytoplasm?

Accepted Answer

A)  type I 
B)  type II 
C)  type III 
D)  type IV 
E)  all of the above 
A)  type I 
B)  type II 
C)  type III 
D)  type IV 
E)  all of the above

Question 9

How does a pathogenicity island increase the "fitness" of a microorganism (pathogen) to interact with a host and cause disease?

Accepted Answer

Pathogenicity islands contain genes that

Question 10

Which of the following diseases is transmitted by the mosquito Aedes aegypti?

Accepted Answer

A)  yellow fever 
B)  Ebola 
C)  epidemic typhus 
D)  listeriosis 
E)  SARS 
A)  yellow fever 
B)  Ebola 
C)  epidemic typhus 
D)  listeriosis 
E)  SARS

Question 11

Describe why a blood agar plate can be used to detect the alpha-hemolytic activity of Staphylococcus aureus.

Accepted Answer

The alpha toxin is secreted by

Question 12

There is no host cell receptor for the enteropathogenic Escherichia coli intimin adhesion. Describe how this pathogen successfully colonizes human intestines.

Accepted Answer

The pathogen uses the type III

Question 13

Which of the following is correct about Salmonella and Shigella?

Accepted Answer

A)  They both produce shiga toxin. 
B)  They are Gram-positive rods. 
C)  They are resistant to gastric acid. 
D)  They cause typhoid fever. 
E)  They are facultative intracellular pathogens. 
A)  They both produce shiga toxin. 
B)  They are Gram-positive rods. 
C)  They are resistant to gastric acid. 
D)  They cause typhoid fever. 
E)  They are facultative intracellular pathogens.

Question 14

Commensals do not need virulence factors to survive on their host because:

Accepted Answer

A)  they are well adapted for their specific niche 
B)  they do not breach the host barriers and immune system 
C)  they are recognized as self by the host 
D)  A and B only 
E)  all of the above 
A)  they are well adapted for their specific niche 
B)  they do not breach the host barriers and immune system 
C)  they are recognized as self by the host 
D)  A and B only 
E)  all of the above

Question 15

State several of the characteristics pertaining to pathogenicity islands that suggest they are remnants of transposition.

Accepted Answer

Pathogenicity islands commonly contain a

Question 16

Tropheryma whipplei is the causative agent for Whipple's disease. It could not be cultured until recently, when the genomic data showed:

Accepted Answer

A)  it was auxotrophic for some amino acids 
B)  it was an obligate intracellular pathogen 
C)  it needed a helper virus to grow 
D)  it needed high levels of iron 
E)  it is a virus that needed cell culture 
A)  it was auxotrophic for some amino acids 
B)  it was an obligate intracellular pathogen 
C)  it needed a helper virus to grow 
D)  it needed high levels of iron 
E)  it is a virus that needed cell culture

Question 17

The toxin gene in Corynebacterium diphtheriae is located on:

Accepted Answer

A)  plasmid 
B)  mobile genes called transposons 
C)  bacterial chromosomes 
D)  lysogenic phage genomes 
E)  all of the above 
A)  plasmid 
B)  mobile genes called transposons 
C)  bacterial chromosomes 
D)  lysogenic phage genomes 
E)  all of the above

Question 18

What characteristics of a pathogen distinguish it from a commensal, in terms of its ability to infect and replicate within a eukaryotic host?

Accepted Answer

Commensals are essentially relegated to

Question 19

Two Streptococcus pneumoniae strains, agent 1 and agent 2, are administered to groups of animals at different doses. Mortality rates are then measured for the animals that received each dose level of each agent. Agent 1 is found to have an LD50 of 400. Agent 2 is found to have an LD50 of 600. Which one is producing a capsule and which one is not? How do you know?

Accepted Answer

Agent 1 (strain 1) is producin

Question 20

Type IV pili are essential for the interaction of Neisseria meningitidis with brain endothelial cells. Describe the difference between the type IV and type I pili binding, and why knowing the type of binding is important in pathogenesis.

Accepted Answer

Type I pili adhere to mannose residues o

Exam 25: Microbial Pathogenesis

Descibe two specific nonpili protein adhesins used in pathogenesis.

Bacteria whose optimum growth temperature is 37°C and that produce copious amounts of polysaccharides and capsules are most likely to be:

Protein A helps Staphylococcus aureus avoid:

The current classification of bacteria pili is based on __________ rather than __________.

What do the anthrax, Escherichia coli, cholera, and Bordetella toxins have in common?

Multivalent adhesion molecule 7, or MAM7, is a unique adhesion because it:

Which of the following does NOT result from the release of endotoxin from Gram-negative bacteria?

Which of the following protein secretory systems injects effector molecules directly from the bacterial cytoplasm into the host cytoplasm?

How does a pathogenicity island increase the "fitness" of a microorganism (pathogen) to interact with a host and cause disease?

Which of the following diseases is transmitted by the mosquito Aedes aegypti?

Describe why a blood agar plate can be used to detect the alpha-hemolytic activity of Staphylococcus aureus.

There is no host cell receptor for the enteropathogenic Escherichia coli intimin adhesion. Describe how this pathogen successfully colonizes human intestines.

Which of the following is correct about Salmonella and Shigella?

Commensals do not need virulence factors to survive on their host because:

State several of the characteristics pertaining to pathogenicity islands that suggest they are remnants of transposition.

Tropheryma whipplei is the causative agent for Whipple's disease. It could not be cultured until recently, when the genomic data showed:

The toxin gene in Corynebacterium diphtheriae is located on:

What characteristics of a pathogen distinguish it from a commensal, in terms of its ability to infect and replicate within a eukaryotic host?

Type IV pili are essential for the interaction of Neisseria meningitidis with brain endothelial cells. Describe the difference between the type IV and type I pili binding, and why knowing the type of binding is important in pathogenesis.

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

Viruses

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Bio-techniques and Synthetic Biology

Energetics and Catabolism

Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

Biosynthesis

Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

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