Question 1

Define a fomite and give at least two specific examples.

Accepted Answer

A fomite is an inanimate object that when contaminated may be a mechanism for indirect transmission of a pathogen. Examples would be a shared hypodermic needle, contaminated tissues, or the dressing served at Thanksgiving dinner.

Question 2

Which of the following techniques would be used to identify unknown virulence genes that are only expressed in the host?

Accepted Answer

A)  in situ hybridization of cultured bacteria 
B)  creating a genomic library of open reading frames of pathogen 
C)  mutational studies in vitro 
D)  culture techniques 
E)  in vivo expression technology 
A)  in situ hybridization of cultured bacteria 
B)  creating a genomic library of open reading frames of pathogen 
C)  mutational studies in vitro 
D)  culture techniques 
E)  in vivo expression technology E

Question 3

Synthesis of flagella and pili filaments in Gram-negatives share which of the following attributes?

Accepted Answer

A)  Protein export systems are used to deliver subunits to the outside. 
B)  Chaperones are not needed for protein transport. 
C)  There is no periplasmic stopover. 
D)  Flagellar and pili proteins are added in sequence intracellularly. 
E)  Flagellar and pili proteins do not extend beyond the periplasm. 
A)  Protein export systems are used to deliver subunits to the outside. 
B)  Chaperones are not needed for protein transport. 
C)  There is no periplasmic stopover. 
D)  Flagellar and pili proteins are added in sequence intracellularly. 
E)  Flagellar and pili proteins do not extend beyond the periplasm. A

Question 4

A life-threatening lung infection caused by biofilm formation in cystic fibrosis patients is

Accepted Answer

A)  Pseudomonas aeruginosa. 
B)  Staphylococcus epidermidis. 
C)  Mycobacterium tuberculosis. 
D)  Vibrio cholerae. 
E)  Bordetella pertussis. 
A)  Pseudomonas aeruginosa. 
B)  Staphylococcus epidermidis. 
C)  Mycobacterium tuberculosis. 
D)  Vibrio cholerae. 
E)  Bordetella pertussis.

Question 5

Which of the following is a nonproteinaceous, yet toxic, compound found in all Gram-negative bacteria?

Accepted Answer

A)  endotoxin 
B)  exotoxin 
C)  type I pili 
D)  type III pili 
E)  type IV pili 
A)  endotoxin 
B)  exotoxin 
C)  type I pili 
D)  type III pili 
E)  type IV pili

Question 6

E. coli O157:H7 has a very low infectious dose because

Accepted Answer

A)  it is encapsulated. 
B)  disease results from a synergistic action with Shigella. 
C)  it is resistant to usually lethal gastric acid. 
D)  the intestine has many receptors for the toxin. 
E)  it secretes a superantigen. 
A)  it is encapsulated. 
B)  disease results from a synergistic action with Shigella. 
C)  it is resistant to usually lethal gastric acid. 
D)  the intestine has many receptors for the toxin. 
E)  it secretes a superantigen.

Question 7

What are ubiquitination signals? Describe how a microbe can redirect these signals for its own purposes.

Accepted Answer

Ubiquitination signals are a cellular re

Question 8

What would be expected to happen to the Helicobacter pylori bacteria in a patient who has taken a large amount of antacids in the last month?

Accepted Answer

Antacids would reduce the pH of the stom

Question 9

Bacteria that exhibit antigenic shifts and phase variations will most likely cause

Accepted Answer

A)  host immunity. 
B)  recurrent infections in the exposed host. 
C)  death each time a host is infected. 
D)  subclinical infections. 
E)  mild, acute infections. 
A)  host immunity. 
B)  recurrent infections in the exposed host. 
C)  death each time a host is infected. 
D)  subclinical infections. 
E)  mild, acute infections.

Question 10

What process is occurring in the figure below? Describe that process.

Accepted Answer

This shows a type IV system sh

Question 11

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 12

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 13

Superantigens

Accepted Answer

A)  bore holes on eukaryotic cell membranes. 
B)  inhibit phagocytosis. 
C)  prevent degranulation of macrophages. 
D)  are antipyrogenic. 
E)  activate immune cells without being processed. 
A)  bore holes on eukaryotic cell membranes. 
B)  inhibit phagocytosis. 
C)  prevent degranulation of macrophages. 
D)  are antipyrogenic. 
E)  activate immune cells without being processed.

Question 14

Yellow fever and West Nile virus are both

Accepted Answer

A)  cancer causing. 
B)  hemorrhagic viruses. 
C)  close relatives of herpes virus. 
D)  diarrheagenic viruses. 
E)  flaviviruses. 
A)  cancer causing. 
B)  hemorrhagic viruses. 
C)  close relatives of herpes virus. 
D)  diarrheagenic viruses. 
E)  flaviviruses.

Question 15

Binding of the protein ________ of the EPEC pathogenicity system directly triggers a remarkable reorganization of host cellular cytoskeletal components.

Accepted Answer

A)  actin 
B)  SPI-1 
C)  intimin 
D)  Nef 
E)  Ivet 
A)  actin 
B)  SPI-1 
C)  intimin 
D)  Nef 
E)  Ivet

Question 16

A chef cut her finger accidentally. The next morning, she felt pain and warmth and had a little swelling and redness on that finger (which are signs of inflammation). By that night, she was just fine. Which of the following pertains to the chef?

Accepted Answer

A)  She had an overt microbial disease. 
B)  She had an infection. 
C)  The inflammation was a response to the cut, not a microbe. 
D)  Microbial toxins, not the vegetative cells, induced inflammation. 
E)  The cut introduced ectoparasites that could not survive. 
A)  She had an overt microbial disease. 
B)  She had an infection. 
C)  The inflammation was a response to the cut, not a microbe. 
D)  Microbial toxins, not the vegetative cells, induced inflammation. 
E)  The cut introduced ectoparasites that could not survive.

Question 17

Agent A has an LD₅₀ of 400. Agent B has an LD₅₀ of 600. Which is the more pathogenic agent, A or B? What is the relationship between this measure and microbial virulence?

Accepted Answer

Agent A is more virulent than agent B. V

Question 18

Salmonella and Shigella both

Accepted Answer

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

Question 19

There is no host cell receptor for the enteropathogenic Escherichia coli intimin adhesion. How does this pathogen successfully colonize human intestines?

Accepted Answer

The pathogen uses the type III

Question 20

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

Exam 25: Microbial Pathogenesis

Define a fomite and give at least two specific examples.

Which of the following techniques would be used to identify unknown virulence genes that are only expressed in the host?

Synthesis of flagella and pili filaments in Gram-negatives share which of the following attributes?

A life-threatening lung infection caused by biofilm formation in cystic fibrosis patients is

Which of the following is a nonproteinaceous, yet toxic, compound found in all Gram-negative bacteria?

E. coli O157:H7 has a very low infectious dose because

What are ubiquitination signals? Describe how a microbe can redirect these signals for its own purposes.

What would be expected to happen to the Helicobacter pylori bacteria in a patient who has taken a large amount of antacids in the last month?

Bacteria that exhibit antigenic shifts and phase variations will most likely cause

What process is occurring in the figure below? Describe that process.

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

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

Superantigens

Yellow fever and West Nile virus are both

Binding of the protein ________ of the EPEC pathogenicity system directly triggers a remarkable reorganization of host cellular cytoskeletal components.

A chef cut her finger accidentally. The next morning, she felt pain and warmth and had a little swelling and redness on that finger (which are signs of inflammation). By that night, she was just fine. Which of the following pertains to the chef?

Agent A has an LD₅₀ of 400. Agent B has an LD₅₀ of 600. Which is the more pathogenic agent, A or B? What is the relationship between this measure and microbial virulence?

Salmonella and Shigella both

There is no host cell receptor for the enteropathogenic Escherichia coli intimin adhesion. How does this pathogen successfully colonize human intestines?

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

Biotechniques 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

Filters

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