Here are the important microbiology mcqs with answers in chapter 10.
1. What is the primary mechanism by which bacteria develop resistance to antibiotics?
a) Mutation
b) Conjugation
c) Transformation
d) All of the above
Answer: b) Conjugation
2. Which of the following statements about antibiotic resistance is true?
a) Antibiotic resistance is only a problem in developing countries.
b) Antibiotic resistance is solely caused by the overuse of antibiotics.
c) Antibiotic resistance can develop naturally over time.
d) Antibiotic resistance is reversible once it occurs.
Answer: c) Antibiotic resistance can develop naturally over time.
3. What term describes the ability of bacteria to survive exposure to an antibiotic that would normally kill them?
a) Antibiotic susceptibility
b) Antibiotic tolerance
c) Antibiotic resistance
d) Antibiotic persistence
Answer: c) Antibiotic resistance
4. Which of the following is NOT a common way that bacteria acquire antibiotic-resistance genes?
a) Mutation
b) Horizontal gene transfer
c) Transformation
d) Vertical gene transfer
Answer: d) Vertical gene transfer
5. How can antibiotic resistance be slowed down or minimized?
a) Prescribing antibiotics for viral infections
b) Using broad-spectrum antibiotics whenever possible
c) Completing the full course of antibiotics as prescribed
d) Using antibiotics only when absolutely necessary
Answer: d) Using antibiotics only when absolutely necessary
6. Which type of antibiotic is most susceptible to resistance development due to its narrow spectrum of activity?
a) Broad-spectrum antibiotics
b) Penicillins
c) Macrolides
d) Fluoroquinolones
Answer: b) Penicillins
7. What is one of the major consequences of antibiotic resistance?
a) Decreased healthcare costs
b) Increased treatment success rates
c) Longer hospital stays
d) Lower patient mortality rates
Answer: c) Longer hospital stays
8. What is the primary target of antibiotics in bacterial cells?
a) Ribosomes
b) Cell membrane
c) Nucleus
d) Mitochondria
Answer: a) Ribosomes
9. Which of the following best describes a superbug?
a) A term used to describe a particularly large bacterium
b) A bacterium that has developed resistance to multiple antibiotics
c) A bacterium that is sensitive to all antibiotics
d) A bacterium that is found in extreme environments
Answer: b) A bacterium that has developed resistance to multiple antibiotics
10. What is one of the strategies to combat antibiotic resistance?
a) Prescribing higher doses of antibiotics
b) Developing new antibiotics more slowly
c) Using combination therapy with multiple antibiotics
d) Discontinuing the use of antibiotics altogether
Answer: c) Using combination therapy with multiple antibiotics
11. Which of the following is an example of a gram-negative bacterium known for its antibiotic resistance?
a) Staphylococcus aureus
b) Escherichia coli (E. coli)
c) Streptococcus pyogenes
d) Clostridium difficile
Answer: b) Escherichia coli (E. coli)
12. What is the primary reason behind the overuse and misuse of antibiotics?
a) To promote the development of antibiotic resistance
b) To reduce the cost of healthcare
c) To prevent bacterial infections
d) To speed up the recovery from viral infections
Answer: d) To speed up the recovery from viral infections
13. What is the term for the phenomenon where bacteria that were once susceptible to an antibiotic become resistant to it over time?
a) Antibiotic mutation
b) Antibiotic insensitivity
c) Antibiotic switching
d) Antibiotic adaptation
Answer: d) Antibiotic adaptation
14. Which of the following factors contributes to the rapid spread of antibiotic resistance in healthcare settings?
a) Strict infection control measures
b) Rapid development of new antibiotics
c) Frequent patient transfers between healthcare facilities
d) Limited use of antibiotics
Answer: c) Frequent patient transfers between healthcare facilities
15. What is the name of the enzyme produced by some bacteria that inactivates beta-lactam antibiotics like penicillin?
a) Ribonuclease
b) Beta-lactamase
c) DNA polymerase
d) RNA ligase
Answer: b) Beta-lactamase
16. Which of the following is NOT a common mechanism of antibiotic resistance in bacteria?
a) Efflux pumps
b) Cell wall synthesis inhibition
c) Target site modification
d) Enhanced antibiotic uptake
Answer: d) Enhanced antibiotic uptake
17. What is the term for the process by which antibiotic-resistant genes can be transferred from one bacterial species to another through direct contact or exchange of genetic material?
a) Vertical gene transfer
b) Horizontal gene transfer
c) Gene inversion
d) Gene duplication
Answer: b) Horizontal gene transfer
18. Which of the following infections is most likely to be caused by a superbug?
a) Common cold
b) Strep throat
c) Urinary tract infection
d) Tuberculosis
Answer: d) Tuberculosis
19. What can individuals do to help combat antibiotic resistance?
a) Request antibiotics for viral infections
b) Share antibiotics with friends and family
c) Follow healthcare provider’s instructions for antibiotic use
d) Store antibiotics in a warm, humid environment
Answer: c) Follow the healthcare provider’s instructions for antibiotic use
20. Which class of antibiotics is known for its potential to cause Clostridium difficile infection, a common healthcare-associated infection?
a) Tetracyclines
b) Macrolides
c) Fluoroquinolones
d) Aminoglycosides
Answer: c) Fluoroquinolones
21. What is the primary mode of action of antibiotics that inhibit bacterial protein synthesis, such as tetracyclines?
a) Disrupting cell membrane integrity
b) Inhibiting DNA replication
c) Inhibiting RNA synthesis
d) Blocking ribosome function
Answer: d) Blocking ribosome function
22. Which of the following best describes “antibiotic stewardship”?
a) The practice of prescribing antibiotics for every suspected bacterial infection
b) The responsible use of antibiotics to preserve their effectiveness and minimize resistance
c) The rapid development of new antibiotics to combat resistance
d) The promotion of over-the-counter antibiotic sales
Answer: b) The responsible use of antibiotics to preserve their effectiveness and minimize resistance
23. Which of the following is an example of an antibiotic-resistant “superbug” that has caused significant healthcare challenges?
a) Streptococcus pneumoniae
b) Mycobacterium tuberculosis
c) Methicillin-resistant Staphylococcus aureus (MRSA)
d) Salmonella enterica
Answer: c) Methicillin-resistant Staphylococcus aureus (MRSA)
24. What is the term for the phenomenon where antibiotics that are no longer effective against a bacterial infection must be replaced by more potent antibiotics?
a) Antibiotic escalation
b) Antibiotic cycling
c) Antibiotic rotation
d) Antibiotic substitution
Answer: b) Antibiotic cycling
25. Which of the following is NOT a common strategy used by bacteria to resist the action of antibiotics?
a) Increasing antibiotic uptake
b) Modifying antibiotic targets
c) Inactivating antibiotics
d) Decreasing antibiotic efflux
Answer: a) Increasing antibiotic uptake
26. What is the primary reason behind the development of antibiotic resistance in agriculture?
a) The use of antibiotics to treat sick animals
b) The use of antibiotics as growth promoters
c) The absence of antibiotics in animal agriculture
d) The implementation of strict regulations on antibiotic use
Answer: b) The use of antibiotics as growth promoters
27. Which of the following is a key strategy to prevent the spread of antibiotic resistance within healthcare facilities?
a) Frequent use of broad-spectrum antibiotics
b) Strict hand hygiene and infection control measures
c) Prescribing antibiotics for viral infections
d) Using antibiotics without a prescription
Answer: b) Strict hand hygiene and infection control measures
28. What is the term for a bacterium that is resistant to all known antibiotics and poses a significant threat to public health?
a) Antibiotic-sensitive bacterium
b) Antibiotic-tolerant bacterium
c) Extensively drug-resistant bacterium
d) Antibiotic-resistant bacterium
Answer: c) Extensively drug-resistant bacterium
29. Which class of antibiotics is known for its activity against Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB)?
a) Beta-lactams
b) Aminoglycosides
c) Quinolones
d) Rifamycins
Answer: d) Rifamycins
30). How can plasmids contribute to drug resistance in bacteria?
a) By encoding antibiotic drugs
b) By providing a physical barrier to antibiotics
c) By carrying genes that confer resistance to antibiotics
d) By blocking antibiotic entry into bacterial cells
Answer: c) By carrying genes that confer resistance to antibiotics
31. How can genetic mutations contribute to antibiotic resistance in bacteria?
a) They make bacteria more susceptible to antibiotics.
b) They reduce bacterial replication rates.
c) They can alter the structure of antibiotic targets, making them less susceptible to antibiotics.
d) They increase bacterial sensitivity to antibiotics.
Answer: c) They can alter the structure of antibiotic targets, making them less susceptible to antibiotics.
32. Which of the following is an example of a plasmid-encoded resistance gene often found in bacteria?
a) Tetracyclinas
b) Penicillinase
c) Streptomycinase
d) Ampicillinase
33. Plasmid-mediated drug resistance can spread between bacteria of different species through a process called:
a) Binary fission
b) Conjugation
34. Which of the following antibiotics is often affected by plasmid-mediated drug resistance mechanisms?
a) Antivirals
b) Antifungals
c) Beta-lactam antibiotics
35. What is the primary advantage of plasmid-mediated drug resistance for bacteria?
a) Increased susceptibility to antibiotics
b) Enhanced growth rate
c) Improved DNA replication
d) Survival in the presence of antibiotics