Deck 7: Hostmicrobe Interactions and Principles of Disease

Question 1

A person is said to be colonised by a pathogen when

A)the pathogen establishes itself in a body site without causing infection.
B)the pathogen can be removed by regular soap washing.
C)the pathogen causes an immune response.
D)there is visible inflammation at the site.
E)none of the above are correct because pathogens only infect and never colonise.

Answer 1

A

Question 2

Which of the following statements is TRUE?

A)The composition of the intestinal microbiota never changes.
B)Stomach acid stimulates the growth of pathogenic microorganisms.
C)Intestinal bacteria are always aerobic.
D)All intestinal bacteria are potentially harmful.
E)None of the above.

Answer 2

E

Question 3

The term 'normal microbiota' refers to microorganisms which

A)are found only on hospitalised patients.
B)normally inhabit parts of the human body.
C)normally exist in the environment.
D)are found only on human skin.
E)never cause disease.

Answer 3

B

Question 4

Which of the following is a benefit provided by the normal flora?

A)Creation of an environment that inhibits the growth of other microorganisms.
B)Excretion of chemicals with antibacterial activity.
C)Production of vitamins.
D)Maintenance of an optimal pH at some sites.
E)All of the above.

Question 5

A parasite is an organism that

A)lives on another organism.
B)derives its nutrients from another living organism.
C)causes damage to another living organism.
D)uses a host as a source of nutrients but doesn't kill it.
E)all of the above.

Question 6

Organisms that cause disease only when the body's defences are lowered are called

A)contaminants.
B)commensals.
C)transient.
D)opportunists.
E)colonisers.

Question 7

Which of the following is usually an endogenous infection?

A)Urinary tract infection.
B)Tetanus.
C)Rabies.
D)Sexually transmitted infection.
E)Influenza.

Question 8

Plaque consists of

A)an aggregation of all of the bacteria in the mouth.
B)a matrix of glycoproteins containing bacteria.
C)contaminant bacteria in the mouth.
D)the bacteria responsible for gum disease.
E)all of the above.

Question 9

Handwashing aims to remove which organisms from hands?

A)The normal microbiota.
B)The resident microbiota.
C)Commensals.
D)Transient contaminants.
E)All of the above.

Question 10

The capacity of a microorganism to cause disease is termed

A)endogenous.
B)opportunistic.
C)pathogenicity.
D)exogenous.
E)susceptibility.

Question 11

Which of the following statements is TRUE?

A)Newborn babies do not have a microbiota because they are washed with antiseptics at birth.
B)Babies born by caesarean versus a natural birth are more likely to acquire infection from the mother.
C)A newborn baby does not have an intestinal microbiota as long as it is breastfed.
D)The human foetus while it is growing in the uterus contains the same microbiota as the mother.
E)None of the above.

Question 12

Commensalism is a relationship between two organisms in which

A)one organism benefits at the expense of the other.
B)both organisms benefit to an equal amount.
C)one organism benefits without harming the other.
D)neither organism benefits or is harmed.
E)both organisms are adversely affected.

Question 13

Which of the following contributes to the virulence of a bacterium?

A)Presence of a capsule.
B)Presence of attachment pili.
C)Production of toxins.
D)Invasiveness.
E)All of the above.

Question 14

An example of mutualism is

A)Candida albicans infection in the mouth.
B)Staphylococcus aureus colonising the nose.
C)Lactobacilli living in the vagina.
D)Escherichia coli living in the bladder.
E)Staphylococcus epidermidis colonising a catheter.

Question 15

Which of the following statements is TRUE?

A)Symbiosis refers to different organisms living together.
B)Symbiotic relationships are never damaging to either member.
C)A parasite and its host are not in a symbiotic relationship.
D)Symbiotic relationships always benefit both members.
E)All of the above.

Question 16

The microbes that make up the microbiota of humans

A)can change over a person's lifetime.
B)are influenced by factors such as age,nutritional status and environment.
C)can cause infections in the host.
D)provide various benefits to the host.
E)all of the above.

Question 17

One of the ways in which the microbiota benefits the host is by

A)providing nutrients for the growth of other beneficial microorganisms.
B)inhibiting the growth of harmful microorganisms.
C)providing oxygen for the growth of other microorganisms.
D)removing wastes from the body.
E)all of the above.

Question 18

An infection that occurs when the body's defences are weakened is called

A)contagious.
B)selective.
C)opportunistic.
D)symbiotic.
E)chronic.

Question 19

Which of the following factors increases a person's susceptibility to infection?

A)Old age.
B)Stress.
C)Damaged skin.
D)Cancer chemotherapy.
E)All of the above.

Question 20

In a healthy person,which area of the body has a normal microbiota?

A)Bladder.
B)Heart.
C)Vagina.
D)Lungs.
E)Blood.

Question 21

Pyrogens

A)produce pus at the site of infection.
B)interfere with the inflammatory response.
C)reset the temperature control of the body and cause fever.
D)cause nausea and vomiting.
E)cause vasoconstriction and shivering.

Question 22

Which of the following statements is TRUE?

A)Signs of disease are changes felt by the patient.
B)A symptom is a reliable identifier of a disease.
C)Syndrome is another word for symptoms.
D)Signs of disease are detectable or measurable by an observer.
E)Chronic infections do not have any signs or symptoms.

Question 23

Which of the following statements is TRUE?

A)The presence of fever is often,but not always,an indication of infection.
B)Fever is produced by endogenous chemicals which act on the hypothalamus.
C)Exogenous pyrogens are products of some infectious organisms.
D)Intravenous fluids labelled 'pyrogen-free' do not contain dead bacteria.
E)All of the above.

Question 24

People who have a chronic viral infection

A)have severe,life-threatening symptoms.
B)are not infectious.
C)may not be aware they have a disease.
D)should be isolated.
E)will eventually develop liver cancer.

Question 25

During the prodromal phase of a disease

A)the pathogen is present but there are no symptoms.
B)the patient is recovering from the disease.
C)the patient reports non-specific symptoms.
D)the signs and symptoms enable a definite diagnosis.
E)the patient is not infectious.

Question 26

Which of the following is an example of a secondary infection?

A)Herpes in an immunodeficient patient.
B)Streptococcal sore throat.
C)MRSA in a surgical wound.
D)Middle ear infection in a child with a cold.
E)Urinary tract infection.

Question 27

A fulminating disease is one that

A)results in severe inflammation and swelling.
B)progresses very rapidly.
C)is never fatal.
D)does not provoke an immune reaction.
E)is caused by a fungus.

Question 28

Which of the following statements is TRUE?

A)Some chronic viral infections may lead to cancer.
B)Patients with chronic infections may be infectious.
C)Patients who have typhoid fever may become carriers of the disease.
D)Infection with hepatitis C virus may lead to liver cirrhosis.
E)All of the above.

Question 29

Which of the following viruses is potentially associated with the development of cancer?

A)Human papilloma virus.
B)Epstein-Barr virus.
C)Human herpes virus 8.
D)Hepatitis B virus.
E)All of the above.

Question 30

Inflammation

A)is always characterised by a raised,red lump.
B)is the body's response to tissue injury.
C)results when pyrogens are released.
D)is an immune reaction that results in antibody production.
E)all of the above.

Question 31

The presence of bacteria in the bloodstream without any signs or symptoms is called

A)septicaemia.
B)toxaemia.
C)leukaemia.
D)pyaemia.
E)bacteraemia.

Question 32

Which of the following is an indication of infection?

A)Inflammation.
B)Lymphadenopathy.
C)Rash.
D)Antibody formation.
E)All of the above.

Question 33

The incubation period of a disease

A)is the same for every infection.
B)is the time between exposure to the pathogen and the appearance of signs or symptoms.
C)depends entirely on the dose of pathogens that the person is exposed to.
D)is the period during which the person shows the typical signs and symptoms.
E)is the period before the patient becomes infectious.

Question 34

Which of the following may be a sign of infection?

A)Fever.
B)Inflammation.
C)Rash.
D)Diarrhoea.
E)All of the above.

Question 35

Which of the following factors influences the ability of a microorganism to cause disease?

A)Virulence of the microorganism.
B)Nutritional state of the host.
C)Immune status of the host.
D)Genetic predisposition of the host.
E)All of the above.

Question 36

The spread of an infection from the throat to the meninges of the brain is termed a

A)mixed infection.
B)disseminated infection.
C)fatal infection.
D)localised infection.
E)chronic infection.

Question 37

During which phase of an illness is a person possibly infectious?

A)Incubation period.
B)Carrier phase.
C)Acute phase.
D)Prodromal phase.
E)All of the above.

Question 38

Herpes zoster virus remains in the body for many years after the symptoms of chickenpox have subsided.This is an example of a

A)latent infection.
B)chronic infection.
C)slow infection.
D)superinfection.
E)subclinical infection.

Question 39

A systemic infection is one which

A)occurs on the surface of the body.
B)is contained in one area by an inflammatory reaction.
C)affects multiple tissues or organs.
D)can be treated with topical antibiotics.
E)all of the above.

Question 40

A syndrome is

A)a combination of signs and symptoms.
B)a group of different diseases.
C)a disease which occurs in a specific location.
D)when a person suffers from two or more infections simultaneously.
E)a fatal infection.

Question 41

An infection that doesn't cause any signs or symptoms in a person is called a

A)subclinical infection.
B)superinfection.
C)slow infection.
D)non-infection.
E)systemic infection.

Question 42

An infection that often results from the depletion of a person's normal microbiota is

A)gonorrhoea.
B)dental caries.
C)urinary tract infection.
D)thrush.
E)all of the above.