Skip to main content
Ch. 17 - Skin and Eye Infections
Norman-McKay- Microbiology: Basic and Clinical Principles 2nd Edition
Norman-McKay2nd EditionMicrobiology: Basic and Clinical PrinciplesISBN: 9780137661619Not the one you use?Change textbook
All textbooksNorman-McKay 2nd EditionCh. 17 - Skin and Eye InfectionsProblem 7
Chapter 17, Problem 7

Which of the following is not a virulence factor of P. aeruginosa?
a. Protein A
b, Exotoxins
c. Enzymes that damage host tissues
d. Endotoxins
e. Factors that enhance biofilm formation

Verified step by step guidance
1
Step 1: Understand what a virulence factor is. Virulence factors are molecules produced by pathogens like bacteria that enable them to colonize the host, evade or inhibit the immune response, and cause damage to the host tissues.
Step 2: Review the known virulence factors of Pseudomonas aeruginosa. This bacterium is known for producing exotoxins (such as Exotoxin A), enzymes that damage host tissues (like elastase and proteases), endotoxins (as it is a Gram-negative bacterium with lipopolysaccharide in its outer membrane), and factors that enhance biofilm formation, which help it persist in hostile environments.
Step 3: Analyze each option: Protein A is a virulence factor commonly associated with Staphylococcus aureus, not Pseudomonas aeruginosa.
Step 4: Confirm that exotoxins, enzymes damaging host tissues, endotoxins, and biofilm formation factors are all established virulence factors of P. aeruginosa.
Step 5: Conclude that the option which is not a virulence factor of P. aeruginosa is Protein A.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Virulence Factors

Virulence factors are molecules produced by pathogens that enable them to infect the host, evade the immune system, and cause disease. These include toxins, enzymes, and structures that facilitate colonization and damage to host tissues.
Recommended video:
Guided course
03:05
Virulence

Pseudomonas aeruginosa Virulence Mechanisms

P. aeruginosa is a Gram-negative bacterium known for producing exotoxins, enzymes that degrade host tissues, and biofilm-forming factors. These virulence traits help it establish infections, resist immune responses, and survive in hostile environments.
Recommended video:
Guided course
03:05
Virulence

Endotoxins vs. Exotoxins

Endotoxins are components of the outer membrane of Gram-negative bacteria, released upon cell death, while exotoxins are actively secreted proteins that directly damage host cells. P. aeruginosa primarily produces exotoxins, not endotoxins, as virulence factors.
Recommended video:
Guided course
07:22
Exotoxins vs. Endotoxin Review
Related Practice
Textbook Question

Select ALL the true statements about dermatophytes:

a. They are a group of bacteria that cause cutaneous infections.

b. They may be treated with antifungals without knowing the exact causative agent.

c. They are easily treated with antibiotics.

d. They are commonly acquired from the soil, environment, or animals.

e. They produce enzymes that digest keratin found in hair, nails, and skin.

1141
views
Textbook Question

All of the following are commonly associated with Streptococcus pyogenes EXCEPT:

a. impetigo.

b. cellulitis.

c. scalded skin syndrome.

d. necrotizing fasciitis.

e. strep throat.

1274
views
Textbook Question

Which genus is primarily associated with acne?

a. Staphylococcus

b. Propionibacterium

c. Clostridium

d. Streptococcus

e. Pseudomonas

1172
views
Textbook Question

Conjunctivitis is caused by the following agent types (select ALL that apply):

a. bacteria.

b. viruses.

c. protozoa.

d. fungi.

e. helminths.

1056
views
Textbook Question

Select the false statement about cutaneous candidiasis:

a. The most common causative species is Candida albicans.

b. Candida albicans can be part of normal microbiota.

c. Usage of antibiotics can increase the chance of cutaneous candidiasis.

d. Changes in pH can permit overgrowth.

e. The causative agents are naturally found as mold filaments.

1139
views
Textbook Question

Choose the false statement about HSV-1:

a. Viruses may be transmitted via wrestling mats.

b. Viruses may be transmitted via contact with lesions.

c. Viruses may be transmitted via the saliva of others with the virus.

d. Viruses may reactivate under stress-inducing conditions.

e. Viruses can be easily cured with common antivirals.

1113
views