Deck 16: Microbial Pathogenesis

Question 1

What is the correct order of 5 steps in the process of pathogenesis?
V) microbes enter the host
W) cause damage
X) adhere to host tissues
Y) avoid destruction by host defenses
Z) exit host to continue chain of transmission

A) v ,w, x, y, z
B) v, x, y, w, z
C) v, y, x, w, z
D) v, x, w, y, z

Answer 1

B

Question 2

Why are many aspects of pathogenesis the same no matter the identify of the microbe? (Select all that apply)

A) because they share common entry and exit sites
B) because innate host defenses try to fight them off the same way
C) because adaptive host defenses follow the same pathways regardless of pathogen identity
D) because they all cause damage to the host in the same way

Answer 2

A,B,C

Question 3

The type of transmission shown is

A) Direct contact
B) Indirect contact
C) Mechanical vector
D) Common vehicle

Answer 3

B

Question 4

Pathogenesis

A) natural habitat or host of pathogen until it finds a new host
B) pathogens remain with their host and cannot be transmitted
C) infectious disease shared by animals and humans
D) origin and development of a disease

Question 5

Communicable pathogens

A) pathogens remain with their host and cannot be transmitted
B) infectious disease shared by animals and humans
C) origin and development of a disease
D) pathogens may be transmitted to other hosts

Question 6

The natural habitat or host of pathogen until it finds a new host

A) Pathogenesis
B) Reservoir
C) Communicable pathogens
D) Noncommunicable pathogens

Question 7

When pathogens remain with their host and cannot be transmitted

A) Reservoir
B) Communicable pathogens
C) Noncommunicable pathogens
D) Zoonosis

Question 8

An infectious disease shared by animals and humans

A) Reservoir
B) Communicable pathogens
C) Noncommunicable pathogens
D) Zoonosis

Question 9

What are 3 general categories of reservoirs?

A) humans, other animals, and environmental sources
B) humans, other animals and inanimate objects
C) humans, inanimate objects and environmental sources
D) humans, environmental sources, and zoonoses

Question 10

The three basic modes of pathogen transmission from one host to another include

A) contact transmission, vector-borne transmission, and common vehicle transmission
B) contact transmission, indirect transmission and common vehicle transmission
C) contact transmission, direct transmission and indirect transmission
D) contact transmission, vector-borne transmission and indirect transmission

Question 11

very small droplets that can travel about 1 meter

A) Direct contact
B) Indirect contact
C) Droplet transmission
D) Common vehicle transmission

Question 12

The type of transmission that requires physical contact with the microbe

A) Direct contact
B) Indirect contact
C) Droplet transmission
D) Common vehicle transmission

Question 13

The type of transmission that involves a fomite as an intermediate between reservoir and host

A) Direct contact
B) Indirect contact
C) Droplet transmission
D) Common vehicle transmission

Question 14

Which of the following is a mechanical vector?

A) mosquito
B) house fly
C) tick
D) flea

Question 15

Which of the following is a biological vector?

A) house fly
B) cockroach
C) tick
D) ant

Question 16

Which of the following are characteristics of common vehicle transmission (Select all that apply)

A) common vehicle or medium needed to carry pathogen to new host
B) may lead to a very slow spread of pathogens to many people
C) examples of vehicles include food, air, water or blood
D) water may carry pathogens from wild animal population to human community

Question 17

Which of the following statements about air as an example of common vehicle transmission is true? (Select all that apply)

A) air transmission of microbes can occur via droplets capable of remaining airborne for some period of time
B) microbes suspended in droplet nuclei are very large and therefore do not easily enter the lungs
C) microbes carried in the air are quite contagious because they can travel for more than 1 meter
D) serving as human reservoirs, infected individuals can spread contagious microbes like tuberculosis and whooping cough via droplets in the air

Question 18

Blood may serve as a vehicle for which of these pathogens? (Select all that apply)

A) Hepatitis B virus
B) Human Immunodeficiency Virus
C) coli
D) Varicella zoster virus

Question 19

Which of these is an example of vertical transmission?

A) water to human host
B) biological vector like mosquito
C) pregnant mother to unborn fetus
D) airborne tuberculosis bacterium

Question 20

The term perinatal infections best describes

A) vertically transmitted infections that occur within the first trimester of a pregnancy
B) vertically transmitted infections that occur within the second trimester of a pregnancy
C) vertically transmitted infections that occur between 22 weeks of pregnancy and 7 days post birth
D) vertically transmitted infections that occur any time during pregnancy

Question 21

TORCH stands for the pathogens that can cross the placental barrier during development and cause disease in the developing fetus. Which of the following is part of TORCH?

A) Toxoplasma gondii
B) Hepatitis, chickenpox, syphilis
C) Rubeola
D) Cytomegalovirus

Question 22

What is the difference between horizontal and vertical transmission of a pathogenic microbe? (Select all that apply)

A) horizontal transmission is a transfer from a reservoir to human host
B) most infectious diseases are transmitted horizontally
C) vertical transmission is a transfer from mother to unborn child
D) pathogens that are transmitted vertically quickly spread through a population

Question 23

Neonatal ophthalmia (Select all that apply)

A) Staphylococcus aureus
B) Chlamydia trachomatis
C) Neiserria gonorrhoeae
D) coli

Question 24

Impetigo sticky eye

A) Staphylococcus aureus
B) Chlamydia trachomatis
C) Neiserria gonorrhoeae
D) coli

Question 25

In the case study of the Cholera Epidemic in Goma, Zaire in 1994, several risk factors for this severe diarrheal disease were pointed out. Which of the following would be considered risk factors for any outbreak of cholera? (Select all that apply)

A) lack of clean drinking water
B) fecal pollution of drinking water
C) overcrowded refugee camps
D) no latrines available

Question 26

Portals of entry include

A) skin, mucous membranes, parenteral route and environmental sources
B) skin, mucous membranes, and environmental sources
C) skin, mucous membranes and parenteral route
D) skin, parenteral route and environmental sources

Question 27

Pathogens have a difficult time adhering to tissues because (Select all that apply)

A) urination and vaginal secretions carry would-be pathogens out of the body
B) mucociliary escalator in the respiratory tract carry out trapped pathogens
C) peristalsis in GI tract compacts pathogens into feces
D) the skin does not have any adhesins for pathogens to attach

Question 28

Which of the following are characteristic of adhesins (Select all that apply)

A) adhesin on microbe attaches to receptor on host cell
B) receptor on microbe attaches or adheres to adhesin on host cell
C) adhesins are usually made of a protein or glycoprotein
D) shape of adhesion is complementary to receptor on surface of host cell

Question 29

Measles virus spreads systemically throughout body causing a rash

A) Local Infection
B) Focal Infection
C) Systemic infection
D) Surface infection

Question 30

Erysipelas caused by Streptococcus pyogenes remains in primary area

A) Local Infection
B) Focal Infection
C) Systemic infection
D) Surface infection

Question 31

Streptococcus pneumoniae moves from lungs to the heart

A) Local Infection
B) Focal Infection
C) Systemic infection
D) Surface infection

Question 32

What specific host defenses make it difficult for a pathogen to avoid destruction once they have gained entry into the human body? (Select all that apply)

A) circulating antibodies
B) presence of phagocytic cells that destroy pathogens
C) cytotoxic T cells that destroy invaded cells
D) the skin and mucous membranes

Question 33

Where can pathogens temporarily hide from the immune system? (Select all that apply)

A) inside host cells where they can multiply undetected
B) in the prostate gland
C) within epithelial tissues where there is no direct connection to the circulatory system
D) protected tissues like the CNS or synovial joints

Question 34

An example of a pathogen that avoids host defenses as shown is

A) Rhinovirus
B) Chlamydia trachomatis
C) Mycobacterium tuberculosis
D) Haemophilus influenzae type b

Question 35

An example of a pathogen that avoids host defenses as shown is

A) Rhinovirus
B) Chlamydia trachomatis
C) Streptococcus pneumoniae
D) Haemophilus influenzae type b

Question 36

An example of a pathogen that avoids host defenses as shown is

A) Rhinovirus
B) Chlamydia trachomatis
C) Mycobacterium tuberculosis
D) Neisseria meningitidis

Question 37

The illustration describes

A) Antigenic drift
B) Antigenic shift
C) Programmed gene switching
D) Genetic recombination

Question 38

The illustration describes

A) Antigenic drift
B) Antigenic shift
C) Programmed gene switching
D) Genetic transposition

Question 39

A pathogen that inhibits the immune system at the site marked V is

A) Measles virus
B) Epstein Barr virus
C) HIV
D) Meningitis-causing bacteria

Question 40

A pathogen that inhibits the immune system at the site marked X is

A) Measles virus
B) Epstein Barr virus
C) HIV
D) Meningitis-causing bacteria

Question 41

A pathogen that inhibits the immune system at the site marked Y is

A) Measles virus
B) Epstein Barr virus
C) HIV
D) Meningitis-causing bacteria

Question 42

A pathogen that inhibits the immune system at the site marked Z is

A) Measles virus
B) Epstein Barr virus
C) HIV
D) Meningitis-causing bacteria

Question 43

A pathogen that inhibits leukocyte function as shown in the illustration is

A) Staphylococcus aureus
B) Streptococcus pneumoniae
C) Mycobacterium tuberculosis
D) Listeria monocytogenes

Question 44

A pathogen that inhibits leukocyte function as shown in the illustration is

A) Staphylococcus aureus
B) Streptococcus pneumoniae
C) Mycobacterium tuberculosis
D) Listeria monocytogenes

Question 45

A pathogen that inhibits leukocyte function as shown in the illustration is

A) Staphylococcus aureus
B) Streptococcus pneumoniae
C) Mycobacterium tuberculosis
D) Listeria monocytogenes

Question 46

A pathogen that inhibits leukocyte function as shown in the illustration is

A) Staphylococcus aureus
B) Streptococcus pneumoniae
C) Mycobacterium tuberculosis
D) Listeria monocytogenes

Question 47

Why is the Gram-negative spirochete Treponema pallidum able to evade immune system detection? (Select all that apply)

A) there are not very many antigenic proteins imbedded in the LPS of the outer membrane
B) the single flagellum is hidden as an axial filament under the outer membrane of the cell wall
C) immune system detection occurs only after an individual cell dies leaving the living progeny able to cause disease
D) T. pallidum can hide inside living cells

Question 48

How does antigenic drift explain the need to get a new flu vaccine every year? (Select all that apply)

A) antigenic drift is the process in which the primary viral antigens like H and N proteins slowly accumulate mutations
B) H and N mutations become so numerous that the resulting proteins cannot be recognized by previously produced antibodies
C) the current vaccine which was developed using the last year's viruses stimulates production of IgG antibodies that will recognize most H and N proteins but a booster is needed to keep IgG levels elevated
D) the current vaccine which was developed using the last year's viruses stimulates production of specific IgG antibodies that will no longer recognize the H and N proteins on the virus

Question 49

Members of the protozoal genus Trypanosoma include species that have programmed gene switching. This means that genes that produce primary surface antigens are shuffled to produce new combinations. How will this affect the pathogen? (Select all that apply)

A) previously produced host antibodies will not be able to recognize the antigens
B) host phagocytic cells will not be able to recognize and destroy the pathogen
C) some members of the species will always be able to survive the host's immune system
D) H and N mutations become so numerous that the resulting proteins cannot be recognized by previously produced antibodies

Question 50

Why do influenza pandemics occur? (Select all that apply)

A) a hybrid virus is produced by antigenic shift
B) no hosts have any previous immunity to the new hybrid produced by antigenic drift
C) worldwide events facilitate the movement of hosts from one continent to another
D) the human portion of a hybrid virus attacks cytotoxic T cells

Question 51

Match the pathogen with the part of the Host Immune System that it damages:
Production of IgA protease that destroys IgA antibodies ultimately allowing virus to enter cerebrospinal fluid and cause meningitis

A) HIV
B) Measles virus
C) Epstein-Barr Virus
D) Haemophilus influenzae type b

Question 52

Infects T cells and suppresses immune system for several weeks including loss of Type IV hypersensitivity responses

A) HIV
B) Measles virus
C) Epstein-Barr Virus
D) Haemophilus influenzae type b

Question 53

Inhibits functions of B and T cells by infection of Helper T cells

A) HIV
B) Measles virus
C) Epstein-Barr Virus
D) Haemophilus influenzae type b

Question 54

Some microbes actually inhibit their own destruction by phagocytic leukocytes thus allowing them to survive and cause damage to host tissues. Which of the following is NOT a correct match?

A) Staphylococcus aureus/produces toxin that kills Helper T cells
B) Streptococcus pneumoniae/presence of capsule prevents phagocytosis
C) Mycobacterium tuberculosis/inhibits capture by phagocytes to avoid being digested
D) Listeria monocytogenes/splits phagolysosome membrane so it can be released into cytoplasm to replicate

Question 55

Pathogenic microbes can directly damage host cells by a variety of methods. Which of the following are intracellular parasites of host cells able to reproduce inside them and killing the host cell in the process? (Select all that apply)

A) viruses using lysogenic cycle
B) Chlamydia and Rickettsia are obligate intracellular pathogenic bacteria
C) Yersinia pestis and Bacillus anthracis replicate inside leukocytes and are transported to lymph nodes
D) Staphylococcus aureus replication inside erythrocytes

Question 56

Lipase

A) Converts fibrinogen to fibrin, causing blood clot formation
B) Damages connective tissue by degrading collagen, a key fiber
C) Damages connective tissues by degrading hyaluronic acid
D) Damages adipose tissues by degrading fats

Question 57

Protease

A) Converts fibrinogen to fibrin, causing blood clot formation
B) Damages connective tissues by degrading hyaluronic acid
C) Degrades proteins
D) Damages adipose tissues by degrading fats

Question 58

The medical condition in the photo is

A) Shock
B) Disseminated intravascular coagulation
C) Peripheral vein thrombosis
D) Adult coagulation syndrome

Question 59

A pathogen that has the growth pattern shown in the photo when grown on blood agar is

A) Streptococcus pyogenes
B) Streptococcus pneumoniae
C) Enterococcus faecalis
D) Staphylococcus epidermidis

Question 60

A pathogen that has the growth pattern shown in the photo when grown on blood agar is

A) Streptococcus pyogenes
B) Streptococcus pneumoniae
C) Enterococcus faecalis
D) Staphylococcus aureus

Question 61

A pathogen that has the growth pattern shown in the photo when grown on blood agar is

A) Streptococcus pyogenes
B) Streptococcus pneumoniae
C) Enterococcus faecalis
D) Staphylococcus aureus

Question 62

Converts fibrinogen to fibrin, causing blood clot formation

A) Hyaluronidase
B) Coagulase
C) Lipase
D) Collagenase

Question 63

Damages connective tissue by degrading collagen, a key fiber

A) Hyaluronidase
B) Coagulase
C) Protease
D) Collagenase

Question 64

Damages connective tissues by degrading hyaluronic acid

A) Hyaluronidase
B) Coagulase
C) Lipase
D) Collagenase

Question 65

Staphylococcus aureus is a major Gram-positive pathogen that produces many different enzymes and toxins capable of damaging host tissues. Examples of the diseases caused by S. aureus include which of the following (Select all that apply)

A) minor infections such as impetigo, boils, and abscesses
B) pharyngitis
C) pneumonia
D) meningitis

Question 66

Streptococcus pyogenes is sometimes referred to as flesh-eating bacteria. The strains of Streptococcus pyogenes that cause necrotizing fasiitis (Select all that apply)

A) produce collagenase and hyaluronidase
B) are able to easily digest fascia and muscle often requiring surgical intervention to save lives
C) produce coagulase that causes clots that block influx of fresh nutrients and oxygen gas
D) produce an endotoxin that causes disseminated intravascular coagulation

Question 67

Characteristics of dermatophytes include (Select all that apply)

A) protozoans that cause superficial infections of the skin
B) produce proteases that digest keratin in outer skin layers
C) absorb small peptides and amino acids from keratin as nutrients
D) are classified as fungal species

Question 68

Endotoxins are

A) the LPS in the cell walls of all Gram-negative bacteria
B) proteins that cause production of interleukin-1 (IL-1) and tumor necrosis factor (TNF) in phagocytic leukocytes
C) proteins that damage tissues to which they attach
D) not pyrogenic

Question 69

Which of the following statements best describes an endotoxin?

A) It is a protein.
B) It may be excreted by both Gram-positive and Gram-negative bacteria.
C) It is often highly toxic and may be fatal
D) It is pyrogenic

Question 70

What are some of the risks associated with the spread of Gram-negative bacteria in the body? (Select all that apply)

A) Growth of Gram-negative bacteria in the blood can lead to septicemia.
B) Overgrowth of Gram-negative bacteria and their exotoxin will induce the production of TNF in leukocytes that engulf them.
C) Large numbers of gram negative bacteria in the blood cause the release of large amounts of TNF that can damage capillaries causing the formation of blood clots, a condition known as Disseminated Intravascular Coagulation (DIC).
D) Large numbers of gram negative bacteria in the blood cause the release of large amounts of TNF that can damage capillaries causing loss of fluid resulting in hypotension and potentially shock.

Question 71

The development of Acute Respiratory Distress Syndrome (ARDS) may occur when (Select all that apply)

A) TNF makes capillaries more permeable and increases plasma leaking out of blood vessels.
B) Lung tissues becomes inflamed as a result of fluid accumulation.
C) Accumulation of excess fluid in the lungs impedes intake of oxygen leading to ARDS
D) Large numbers of gram negative bacteria in the blood cause the release of large amounts of TNF that can damage capillaries causing Disseminated Intravascular Coagulation (DIC).

Question 72

Characteristics of exotoxins include (Select all that apply)

A) They are produced by both Gram-positive and Gram-negative bacteria.
B) They are formed from a combination of proteins and lipids
C) Every exotoxin has a distinct chemical structure.
D) Every exotoxin damages host cells in a unique way.

Question 73

What part do exotoxins play in the disease process? (Select all that apply)

A) They are a key player in the pathogenesis of a specific microbe.
B) Highly virulent pathogens are able to cause diseases such as anthrax, botulism, tetanus and cholera because of the toxins they produce.
C) Because they are proteins, toxins are not readily destroyed by antibodies produced by the host's immune system.
D) Inactivated toxins are the basis of vaccinations called toxoids.

Question 74

Select the statement that correctly completes the following sentence. Toxoid-based vaccines work to protect us against microbial exotoxins that cause disease because _________________________________ (Select all that apply)

A) exotoxins can be rendered temporarily inactive with formalin.
B) changing the chemical structure of protein exotoxins to toxoids makes them safe for use as vaccines.
C) toxoids are immunogenic not pathogenic
D) individuals who receive a booster vaccination throughout their lifetimes can continue to have a high level of antibodies against the specific toxin.

Question 75

Vibrio cholerae

A) TSS toxin
B) Pneumolysin
C) Tetanospasmin
D) Cholera toxin

Question 76

Staphylococcus aureus

A) TSS toxin
B) Pneumolysin
C) Tetanospasmin
D) Cholera toxin

Question 77

Staphylococcus aureusi

A) Heat-stable enterotoxin
B) Pneumolysin
C) Tetanospasmin
D) Cholera toxin

Question 78

Streptococcus pneumoniae

A) TSS toxin
B) Pneumolysin
C) Tetanospasmin
D) Cholera toxin

Question 79

Clostridium tetani

A) TSS toxin
B) Heat-stable enterotoxin
C) Pneumolysin
D) Tetanospasmin

Question 80

TSS

A) Neurotoxin causing a paralytic disease
B) Activates T cells causing massive release of cytokines that may lead to shock and multiple organ
C) Reversal of osmotic gradient in the large intestine
D) Lyses red blood cells