Question 1

Which property of the skin most directly inhibits the growth of most pathogenic bacteria?

Accepted Answer

Low pH

Question 2

A patient presents with a rapidly spreading erythematous rash and fever after a minor cut. Laboratory results show beta-hemolytic, catalase-negative, Gram-positive cocci in chains. Which virulence factor is most responsible for the rapid tissue destruction?

Accepted Answer

Hyaluronidase

Question 3

Which of the following best describes the mechanism of action of lysozyme found in sweat and tears?

Accepted Answer

Hydrolyzes peptidoglycan in bacterial cell walls

Question 4

A child develops a highly contagious, crusted skin infection around the mouth and nose. Which two bacteria are most commonly associated with this condition?

Accepted Answer

Streptococcus pyogenes and Staphylococcus aureus

Question 5

Which of the following is a distinguishing feature of MRSA compared to other Staphylococcus aureus strains?

Accepted Answer

Resistance to methicillin due to altered penicillin-binding proteins

Question 6

A swimmer develops an ear infection after using a public hot tub. The pus is blue-green in color. Which organism is most likely responsible?

Accepted Answer

Pseudomonas aeruginosa

Question 7

Which of the following best explains why antibiotics are often ineffective in treating abscesses caused by Staphylococcus aureus?

Accepted Answer

Antibiotics cannot penetrate the pus-filled abscess

Question 8

A patient with a history of chickenpox develops a painful, localized vesicular rash years later. Which virus is responsible for this reactivation?

Accepted Answer

Varicella-zoster virus (HHV-3)

Question 9

Which of the following is the primary reason why measles infection can lead to increased susceptibility to other diseases?

Accepted Answer

It causes immune amnesia by depleting memory B cells

Question 10

A newborn develops severe conjunctivitis and corneal scarring after birth. The mother is found to have a sexually transmitted infection. Which organism is most likely responsible?

Accepted Answer

Neisseria gonorrhoeae

Question 11

Which of the following best describes the pathogenesis of necrotizing fasciitis caused by Streptococcus pyogenes?

Accepted Answer

Production of SPE superantigens and tissue-degrading enzymes

Question 12

A patient presents with white patches in the mouth and difficulty swallowing after a course of antibiotics. Which organism is most likely responsible?

Accepted Answer

Candida albicans

Question 13

Which of the following is the most effective way to prevent congenital rubella syndrome?

Accepted Answer

Administration of the MMR vaccine to women of childbearing age

Question 14

A patient develops a nodular lesion on the hand after handling roses. The lesion is pink/purple and slowly enlarges. Which organism is most likely responsible?

Accepted Answer

Sporothrix schenckii

Question 15

Which of the following is a common sign of infection with human parvovirus B19?

Accepted Answer

Slapped cheek rash

Question 16

A patient presents with itching and a rash after sleeping in a hotel. Examination reveals burrows in the skin. Which organism is most likely responsible?

Accepted Answer

Sarcoptes scabiei

Question 17

Which of the following is the leading cause of blindness worldwide due to infection?

Accepted Answer

Chlamydia trachomatis (trachoma)

Question 18

Which of the following treatments is most appropriate for moderate inflammatory acne caused by Propionibacterium acnes?

Accepted Answer

Benzoyl peroxide and antibiotics

Question 19

A wrestler develops vesicular lesions on the skin after a tournament. Which virus is most likely responsible?

Accepted Answer

Herpes simplex virus (HSV-1 or HSV-2)

Question 20

Which of the following best explains why the MMR vaccine is effective in preventing both measles and rubella?

Accepted Answer

It contains live attenuated viruses for both diseases

Microbial Diseases of the Skin and Eyes: Structure, Pathogenesis, and Clinical Manifestations

Study Guide - Practice Questions

Study Guide - Flashcards