Question

17. Why are Pseudomonas aeruginosa infections difficult to treat?

A. Because they are gram-positive bacteria, which are harder to treat.

B. Because they form biofilms, which are difficult for antibiotics to penetrate.

C. Because they have a special endotoxin that degrades many antibiotics.

D. Because we do not have any antibiotics that target P. aeruginosa.

18. Which of the following virulence factors are associated with invasion?

A. Biofilms

B. Glycohydrolases

C. Alpha-toxin

D. Coagulase

E. B and C

F. C and D

19. All of the following are examples of virulence factors that directly impact the stages of pathogenesis

A. Helicobacter pylori produces urease which raises the pH of the stomach

B. Influenza virus acquires hemagglutinin neuraminidase spike proteins effectively changing the surface antigens

C. Clostridium botulinum produces botulinum toxin that causes flaccid paralysis

D. MRSA strains produce a penicillin-binding protein that has low affinity for beta-lactam antibiotics

20. Which of the following is false regarding antibiotic resistance?

A. Antibiotic resistance is only an issue in nosocomial infections

B. Superbugs often have multiple mechanisms of resistance

C. Target modification as a resistance mechanism has spread through selective pressure

D. Cross-resistance mechanisms provide resistance to multiple classes of drugs

Answer 1

17. Answer: Option B is correct
Explanation:
Pseudomonas aeruginosa = A gram -ve opportunistic pathogen that causes acute infections of the skin, urinary tract, and respiratory tract. It is an encapsulated rod-shaped (Bacillus) bacteria.

Pseudomonas aeruginosa infections are generally difficult to treat as the bacteria forms biofilms in the host tissues.
Biofilm is a syntrophic consortium of microbes which exhibit special properties such as antibiotic resistance as they do not allow the entry of bacteria into cells.