3 Flashcards
1
Q
- Which of the following best describes commensal flora?
a) Microorganisms that always cause disease
b) Microorganisms that have a beneficial relationship with the host and occupy epithelial surfaces
c) Microorganisms that only exist in the intestines
d) Microorganisms that only cause disease in immunocompromised individuals
A
B
2
Q
- Which of the following is an example of a condition caused by an endogenous infection?
a) A skin infection caused by Staphylococcus aureus after an open wound
b) A respiratory infection caused by Mycobacterium tuberculosis from the environment
c) A urinary tract infection caused by Escherichia coli from contaminated water
d) A viral infection from inhaling airborne particles
A
A
3
Q
- Which of the following is characteristic of a pathogen?
a) It co-evolved with the host to provide benefits
b) It only causes disease under specific conditions or when the immune system is compromised
c) It always causes disease, such as HIV or tuberculosis
d) It is beneficial to the host and does not cause harm
A
C
4
Q
- Which of the following best describes opportunistic pathogens?
a) They always cause disease, regardless of the host’s health status
b) They cause disease only in the presence of a compromised immune system
c) They cause disease under specific environmental conditions
d) They only cause disease when the host is infected by a pathogen
A
B
5
Q
- What is the primary action of antibiotics on the microbiome?
a) They selectively kill pathogens without affecting commensal bacteria
b) They can kill both pathogens and commensal bacteria, disrupting the natural balance
c) They only target viruses and fungi, not bacteria
d) They exclusively kill commensal bacteria and leave pathogens unaffected
A
B
6
Q
- Which of the following is a consequence of antibiotic use on the human microbiome?
a) Increased resistance in commensal bacteria and an increased risk of opportunistic infections
b) Decreased risk of opportunistic infections
c) Increased protection from all infections
d) Complete eradication of all bacteria in the body
A
A
7
Q
- Which of the following is a potential complication of Clostridium difficile infection in the gut?
a) Excessive production of immunoglobulins leading to chronic inflammation
b) Increased gut motility resulting in constipation
c) Damage to the gut lining, leading to diarrhea and fever
d) Suppression of the immune system, leading to systemic infection
A
C
8
Q
- Which of the following is a characteristic of sterile sites in the human body?
a) They are normally colonized by large numbers of commensal bacteria
b) They contain commensal flora that help protect the host
c) They should not contain any microorganisms under normal conditions
d) They are sites where only pathogenic microorganisms reside
A
C
9
Q
- Which of the following is an example of a non-sterile site in the human body?
a) Heart
b) Liver
c) Blood
d) Skin
A
D
10
Q
- Which microorganism is commonly found in the human gut but can proliferate during antibiotic treatment, causing Clostridium difficile infection?
a) Streptococcus pneumoniae
b) Lactobacillus
c) Candida albicans
d) Clostridium difficile
A
D
11
Q
- What is the primary mechanism by which antibiotics contribute to infections such as oral or vaginal thrush?
a) They increase the growth of opportunistic fungi like Candida by disrupting the balance of the microbiome
b) They inhibit the immune system’s ability to recognize pathogens
c) They increase the production of commensal bacteria that protect against infection
d) They suppress the growth of pathogenic fungi and bacteria
A
A
12
Q
- Which of the following body sites is typically sterile?
a) Upper airway
b) Bladder
c) Skin
d) Blood
A
D
13
Q
- Which microorganism is normally present in the human vagina and helps maintain an acidic environment to prevent infections?
a) Escherichia coli
b) Lactobacillus
c) Candida albicans
d) Staphylococcus aureus
A
B
14
Q
- Which of the following best describes infection control?
a) The use of antibiotics to eliminate all microorganisms from the body
b) Preventing the spread of infection by breaking the chain between the pathogen, reservoir, and susceptible host
c) The process of vaccinating individuals to prevent infection
d) The isolation of pathogens in sterile environments only
A
B
15
Q
- Infection control in hospitals aims to break the links between which of the following?
a) The pathogen, its reservoir, and a susceptible host
b) Antibiotics, the pathogen, and its vector
c) The host’s immune response and the pathogen
d) Antibiotics, host defenses, and infection severity
A
A
16
Q
- What is a key feature of commensal flora in the gastrointestinal tract?
a) They help in digestion and protect against pathogenic bacteria by outcompeting them
b) They only exist in the small intestine
c) They secrete toxins that promote disease
d) They are always harmful if they enter the bloodstream
A
A
17
Q
- What action does the use of antibiotics have on commensal flora in the gut?
a) It selectively targets harmful pathogens without affecting beneficial bacteria
b) It can lead to the disruption of the normal microbial ecosystem, making the host susceptible to opportunistic infections
c) It strengthens the immune system by enhancing the growth of beneficial bacteria
d) It completely eradicates all bacteria, including both harmful and beneficial types
A
B
18
Q
- Which of the following is a feature of the human microbiome?
a) It consists only of pathogenic microorganisms
b) It remains unchanged throughout a person’s life
c) It is composed of both beneficial and potentially harmful microorganisms
d) It has no impact on immune function
A
C
19
Q
- What is the primary function of the mucociliary escalator in the airways?
a) To transport immune cells to the lungs
b) To move commensal bacteria out of the lungs
c) To trap and remove pathogens from the respiratory tract
d) To regulate gas exchange in the lungs
A
C
20
Q
- Which of the following is a potential consequence of disrupting the balance of the microbiome with antibiotics?
a) Increased resistance to antibiotics in the gut flora
b) The complete eradication of pathogens from the body
c) Enhanced production of immune cells
d) A complete restoration of normal flora
A
A
21
Q
A
