Microbiology questions and answers pdf download chapter 15, 16

1. Which staining method is commonly used to differentiate between Gram-positive and Gram-negative bacteria?

• A) Acid-fast staining
• B) Ziehl-Neelsen staining
• C) Gram staining
• Correct Answer: C) Gram staining

2. What is the characteristic arrangement of Staphylococcus bacteria?

• A) Chains
• B) Clusters
• C) Pairs
• Correct Answer: B) Clusters

3. Which species of Staphylococcus is commonly found on the skin and mucous membranes of humans?

• A) Staphylococcus aureus
• B) Staphylococcus epidermidis
• C) Staphylococcus pneumoniae
• Correct Answer: B) Staphylococcus epidermidis

4. Streptococcus pneumoniae is known for causing which respiratory infection?

• A) Strep throat
• B) Pneumonia
• C) Tuberculosis
• Correct Answer: B) Pneumonia

5. What is the primary distinguishing feature of Enterococcus among Gram-positive cocci?

• A) Ability to form biofilms
• B) Growth in bile salts
• C) Production of coagulase
• Correct Answer: B) Growth in bile salts

6. Which group of Streptococcus is commonly associated with causing dental caries?

• A) Group A Streptococcus
• B) Group B Streptococcus
• C) Viridans group Streptococcus
• Correct Answer: C) Viridans group Streptococcus

7. Which Gram-positive cocci species is a major cause of skin infections, including boils and abscesses?

• A) Streptococcus pyogenes
• B) Staphylococcus aureus
• C) Enterococcus faecalis
• Correct Answer: B) Staphylococcus aureus

8. What is the primary virulence factor of Staphylococcus aureus?

• A) Hemolysins
• B) Coagulase
• C) Catalase
• Correct Answer: B) Coagulase

9. Which bacterium is associated with causing toxic shock syndrome (TSS)?

• A) Streptococcus pneumoniae
• B) Staphylococcus aureus
• C) Enterococcus faecalis
• Correct Answer: B) Staphylococcus aureus

10. Streptococcus agalactiae is commonly associated with infections in which population?
– A) Neonates
– B) Elderly individuals
– C) Adolescents
– Correct Answer: A) Neonates

11. Which of the following is a characteristic feature of Streptococcus pneumoniae on blood agar?
– A) Beta-hemolysis
– B) Alpha-hemolysis
– C) Gamma-hemolysis
– Correct Answer: B) Alpha-hemolysis

12. What type of hemolysis is typically associated with Staphylococcus aureus on blood agar?
– A) Beta-hemolysis
– B) Alpha-hemolysis
– C) Gamma-hemolysis
– Correct Answer: A) Beta-hemolysis

13. Which of the following is a common manifestation of Streptococcus pyogenes infection?
– A) Impetigo
– B) Urinary tract infection
– C) Meningitis
– Correct Answer: A) Impetigo

14. What is the primary mode of transmission of Streptococcus agalactiae to neonates?
– A) Airborne transmission
– B) Contact with contaminated surfaces
– C) Maternal transmission during childbirth
– Correct Answer: C) Maternal transmission during childbirth

15. Which of the following is a common feature of Enterococcus faecalis?
– A) Optochin sensitivity
– B) Bile salt resistance
– C) Bacitracin resistance
– Correct Answer: B) Bile salt resistance

16. What type of infection is commonly associated with Staphylococcus epidermidis in hospital settings?
– A) Skin infections
– B) Urinary tract infections
– C) Nosocomial infections related to medical devices
– Correct Answer: C) Nosocomial infections related to medical devices

17. Which Streptococcus species is commonly found in the oral cavity and is associated with dental plaque?
– A) Streptococcus pneumoniae
– B) Streptococcus mutans
– C) Streptococcus agalactiae
– Correct Answer: B) Streptococcus mutans

18. What is the primary distinguishing feature of Staphylococcus saprophyticus among Gram-positive cocci?
– A) Formation of biofilms
– B) Urease production
– C) Colonization of the urinary tract
– Correct Answer: C) Colonization of the urinary tract

19. What is the primary mechanism of action of the enzyme catalase produced by Staphylococcus species?
– A) Breakdown of urea
– B) Degradation of lipids
– C) Conversion of hydrogen peroxide to water and oxygen
– Correct Answer: C) Conversion of hydrogen peroxide to water and oxygen

20. Which of the following is a common complication associated with Streptococcus pyogenes infections?
– A) Glomerulonephritis
– B) Hepatitis
– C) Tuberculosis
– Correct Answer: A) Glomerulonephritis

21. What is the primary distinguishing feature of Neisseria species in terms of cellular arrangement?

• A) Chains
• B) Pairs
• C) Clusters
• Correct Answer: B) Pairs

22. Which species of Neisseria is associated with causing gonorrhea?

• A) Neisseria meningitidis
• B) Neisseria gonorrhoeae
• C) Neisseria lactamica
• Correct Answer: B) Neisseria gonorrhoeae

23. Which genus of Gram-negative cocci is associated with infections in immunocompromised individuals and those with underlying medical conditions?

• A) Neisseria
• B) Moraxella
• C) Acinetobacter
• Correct Answer: C) Acinetobacter

24 What is the primary mode of transmission for Moraxella catarrhalis infections?

• A) Airborne transmission
• B) Waterborne transmission
• C) Person-to-person contact
• Correct Answer: C) Person-to-person contact

25. Which Gram-negative cocci species is commonly found as part of the normal flora in the upper respiratory tract?

• A) Moraxella catarrhalis
• B) Neisseria meningitidis
• C) Kingella kingae
• Correct Answer: A) Moraxella catarrhalis

26. Which of the following is a characteristic feature of Acinetobacter species regarding their environmental persistence?

• A) Strict anaerobes
• B) Resistant to desiccation
• C) Sensitive to sunlight
• Correct Answer: B) Resistant to desiccation

27. Kingella kingae is known for causing infections primarily in which age group?

• A) Neonates
• B) Adolescents
• C) Elderly individuals
• Correct Answer: B) Adolescents

28. Which Gram-negative cocci species is associated with endocarditis and infections in individuals with pre-existing heart conditions?
– A) Neisseria gonorrhoeae
– B) Kingella kingae
– C) Haemophilus influenzae
– Correct Answer: B) Kingella kingae

29. What is a notable feature of the colonies of Moraxella catarrhalis on culture media?
– A) Non-motile
– B) Mucoid appearance
– C) Chocolate agar requirement
– Correct Answer: C) Chocolate agar requirement

30. Which Gram-negative cocci species is associated with causing respiratory infections in patients with chronic obstructive pulmonary disease (COPD)?
– A) Neisseria gonorrhoeae
– B) Moraxella catarrhalis
– C) Acinetobacter baumannii
– Correct Answer: B) Moraxella catarrhalis

31. Which species of Neisseria is commonly found as part of the normal flora in the nasopharynx?
– A) Neisseria gonorrhoeae
– B) Neisseria meningitidis
– C) Neisseria lactamica
– Correct Answer: C) Neisseria lactamica

32. Which genus of Gram-negative cocci is often associated with respiratory tract infections in pediatric patients?
– A) Moraxella
– B) Neisseria
– C) Kingella
– Correct Answer: C) Kingella

33. What is the primary route of transmission for Neisseria gonorrhoeae infections?
– A) Airborne transmission
– B) Sexual transmission
– C) Fecal-oral transmission
– Correct Answer: B) Sexual transmission

34. Which of the following is a characteristic feature of Neisseria gonorrhoeae on Thayer-Martin agar?
– A) Gamma-hemolysis
– B) Alpha-hemolysis
– C) Beta-hemolysis
– Correct Answer: C) Beta-hemolysis

35. What type of hemolysis is typically associated with Neisseria species on blood agar?
– A) Beta-hemolysis
– B) Alpha-hemolysis
– C) Gamma-hemolysis
– Correct Answer: B) Alpha-hemolysis

36. Which Gram-negative cocci species is commonly found in the oropharynx and is a common cause of otitis media in children?
– A) Moraxella catarrhalis
– B) Neisseria gonorrhoeae
– C) Haemophilus influenzae
– Correct Answer: C) Haemophilus influenzae

37. What is a common characteristic of Acinetobacter baumannii regarding antibiotic resistance?
– A) Sensitive to most antibiotics
– B) Intrinsic resistance to beta-lactam antibiotics
– C) Strictly anaerobic
– Correct Answer: B) Intrinsic resistance to beta-lactam antibiotics

38. Which Gram-negative cocci species is often associated with infections in the elderly, particularly those with underlying health conditions?
– A) Acinetobacter baumannii
– B) Neisseria meningitidis
– C) Moraxella catarrhalis
– Correct Answer: A) Acinetobacter baumannii