Deck 35: Pathogenicity and Infection

Question 1

Which of the following is a facultative,rather than obligate,intracellular pathogen?

A)Chlamydia
B)Brucella
C)Rickettsia
D)All of the choices are correct.

Answer 1

B

Question 2

A(n)__________ is an organism that transfers pathogens from one host to another.

Answer 2

vector

Question 3

One example of infectious disease transmittion by a fomite is

A)a child developing a cold after playing with a toy that harbored rhinovirus.
B)a baby born with congenital syphilis from an infected mother.
C)a teenager with severe acne due to propionibacteria growing in sebaceous glands.
D)None of the choices are correct.

Answer 3

A

Question 4

Fever response can be triggered by an endogenous pyrogen called interleukin-1.

Question 5

All of the following situations are passive modes of penetration for the invasion of host tissues by opportunistic pathogens EXCEPT

A)a child falling and scraping her knee.
B)a firefighter receiving third-degree burns on the skin.
C)a hiker being bitten by a tick.
D)a bacterium adhering to intravenous tubing,forming a biofilm.

Question 6

Which of the following features of a pathogen is not considered to be a virulence factor when establishing infection within host?

A)Pigment production
B)Attachment fimbriae
C)Slime layer
D)Protein spikes

Question 7

A neutralizing antibody against a toxin is called a(n)__________.

Question 8

An inanimate object that may be contaminated with a pathogen is called a ________.

A)vector
B)fomite
C)zoonoses
D)None of the choices are correct.

Question 9

The term "sexually transmitted infection" is more accurate than "sexually transmitted disease" because it is a sexually transmitted pathogen may colonize host tissues without causing further damage to the host.

Question 10

Once a pathogen has infected the host,__________________ is a measure of the pathogen's ability to spread to adjacent or other tissues.

Question 11

Because LPS is bound to the surface of bacteria,it is called a(n)__________.

Question 12

Vector-borne transmission can be either external or internal.In external (mechanical)transmission,the pathogen is carried

A)on a fomite.
B)on the body surface of a vector.
C)within the vector.
D)All of the choices are correct.

Question 13

Macrophages are phagocytic cells.

Question 14

A person who is infected with a potential pathogen fails to develop signs or symptoms of disease.This correlates with initial microbial dose, microbial lethality,and/or replication rate of the pathogen.

A)low; high; low
B)low; low; high
C)high; low; low
D)high; low; high

Question 15

While exotoxin production is most generally associated with Gram-positive bacteria,some Gram-negative bacteria also produce exotoxins.

Question 16

Colonization specifically refers to the multiplication of a pathogen on or within a host,and includes the resulting tissue invasion and damage.

Question 17

Many types of bacteria are only _________ when dispersing from more stable and heterogeneous communities known as biofilms.

Question 18

Many bacteria are pathogenic because they carry large segments of DNA called __________ _________,which were acquired by horizontal gene transfer,and which carry genes responsible for virulence.

Question 19

In which of the following situations did disease develop due to vertical transmission of the pathogen?

A)A fetus develops listeriosis after unpasteurized cheese infected with Listeria bacteria is consumed by the mother during pregnancy
B)A traveler develops gastroenteritis after drinking water that is contaminated with Escherichia coli bacteria
C)A dog develops rabies after being scratched during a fight with a raccoon that carries the virus
D)A hospitalized patient develops MRSA bacteria in a wound following surgery

Question 20

Exotoxins can be denatured by iodine to form __________,which are useful in vaccines.

Question 21

Endotoxin is released when

A)Gram-negative pathogens lyse or divide.
B)cells are starved for iron.
C)cells are lysogenic for the beta phage.
D)All of the choices are correct.

Question 22

Virulence may be measured experimentally at the host level by the __________ __________ __________,which measures the number of pathogens that kills 50% of an experimental group of hosts within a specified amount of time.

Question 23

Pathogenicity islands are typically associated with

A)genes encoding tRNA.
B)genes encoding rRNA.
C)G+C content similar to the rest of the bacterial genome.
D)None of the choices are correct.

Question 24

A ________________ infection is a disease caused by a parasitic organism that is normally found in animals other than humans.

Question 25

A patient develops a high fever due to a Gram-negative pathogen.Which of the following is a certain mediator of illness in this case?

A)Endotoxin
B)Exotoxin
C)Both endotoxin and exotoxin
D)Neither endotoxin nor exotoxin

Question 26

The capacity of an organism to produce a toxin is called __________.

Question 27

Endotoxins include which of the following?

A)Diphtheria toxin
B)Lipopolysaccharide
C)Tetanus toxin
D)Botulinum toxin

Question 28

The toxic component of lipopolysaccharide is called _________.

A)lipid A
B)exotoxin
C)hemolysin
D)O antigen polysaccharide

Question 29

Inanimate materials involved in pathogen transmission are called reservoirs.

Question 30

The characteristics of a pathogen that determine its virulence include which of the following?

A)Pathogenicity
B)Invasiveness
C)Infectivity
D)All of the choices are correct.

Question 31

Place the events associated with each stage of infectious disease in the correct order with regard to time.
Prodromal stage
Incubation period
Convalescence
Illness period

Question 32

Your brother mentions that several days ago he began to feel as if he was coming down with a cold,but now is no longer experiencing any signs or symptoms and feels fine.Having just studied the infectious disease process in your microbiology course,you immediately recognize that he is describing the phase of illness.

A)prodromal
B)convalescent
C)acute
D)incubation

Question 33

Which of the following is not a characteristic of lipid A?

A)Heat stable
B)Toxic in nanogram amounts
C)Weakly immunogenic
D)Neurotoxic

Question 34

The only organisms to produce endotoxins are Gram-negative bacteria.

Question 35

Generally,exotoxins tend to be more heat stable than endotoxins.

Question 36

Listeria monocytogenes propels itself through mammalian host cells using

A)a modified form of gliding motility.
B)host cell actin and other cytoskeletal proteins.
C)periplasmic flagella.
D)fimbriae-based twitching motility.

Question 37

The term __________ refers to the degree or intensity of pathogenicity.

Question 38

Bacteria within biofilms exchange

A)plasmids.
B)quorum-sensing molecules.
C)nutrients.
D)All of the choices are correct.

Question 39

Transfer of pathogens from host to environment and then to another host are said to be transmitted _________.

Question 40

Which of the following is not a biological effect associated with endotoxin?

A)Coagulation
B)Paralysis
C)Fever
D)Fibrinolysis

Question 41

Which of the following has no effect on the outcome of the host-parasite relationship?

A)The number of parasites on or in the host
B)The virulence of the parasite
C)The defenses of the host
D)All of the choices are correct.

Question 42

Which of the following must a pathogen possess in order for it to be successful at causing infectious disease?

A)Ability to be transported initially to the host
B)Ability to exit the host
C)Ability to adhere to,colonize,or invade the host
D)Ability to damage the host
E)All of the choices are correct.

Question 43

If a symbiont either harms or lives at the expense of another organism,the relationship is called _________.

A)symbiosis
B)parasitism
C)commensalism
D)pathogenicity

Question 44

The final outcome of most host-parasite relationships depends on

A)the number of organisms present in or on the host.
B)the virulence of the organism.
C)the host's defenses.
D)All of the choices are correct.

Question 45

Any organism that can cause disease in the host after direct interaction is a(n)

A)focal pathogen.
B)opportunistic pathogen.
C)primary pathogen.
D)secondary pathogen.

Question 46

An animal that is infected with a parasitic organism that can also infect humans is called a(n)________ host.

A)reservoir
B)endoparasitic
C)transfer
D)intermediate

Question 47

The condition in the host that results from pathogenic parasitic organism growing and multiplying within or on the host is called

A)an infection.
B)an infectious disease.
C)pathogenesis.
D)All of the choices are correct.

Question 48

An __________ pathogen can cause disease in a host with impaired resistance.