***Microbiology Chapter 21***

What do Haemophilus influenzae, Chlamydia trachomitis, and adenoviruses have in common?
They all can cause conjunctivitis.
Which of the following conditions could best be treated using an antiviral medication?
herpetic keratitis
What do herpes simplex virus 1 and Acanthamoeba have in common?
They can both cause keratitis.
A 9-month old baby with a macular rash is brought to the hospital. Parents report that the rash started on the face, spread to the rest of the body, and was preceded with coldlike symptoms. There are small reddish spots in the baby’s mouth. What is the diagnosis?
You have a culture of bacteria that you suspect is either Staphylococcus aureus or Streptococcus pyogenes. Is there any morphological difference between the two?
Yes. S. aureus tends to grow in clusters, whereas S. pyogenes tends to grow in chains.
Which of the following statements concerning necrotizing fasciitis is FALSE?
The tissue damage is mainly due to the production of endotoxin, which stimulates a severe immune response.
A child presents with large red patches of skin. The top layers are peeling off. Because the parents report that the child hasn’t been burned, you suspect that the lesions are due to infection with __________.
Staphylococcus aureus
Fluoroquinolones are the treatment prescribed for otitis externa, which is due to a __________.
bacterial infection
Which statement regarding the skin is FALSE?
Sweat glands produce sebum, in addition to sweat.
Which statement correctly describes the normal microbiota of the skin?
The skin’s normal microbiota are capable of growth at elevated salt concentrations.
Which of the following is NOT a fungal infection?
Dermatophytes are fungi that can infect the __________ because they can grow on/in __________.
outer skin; keratin
Infants may acquire a serious form of conjunctivitis during birth if they are born to a mother infected with __________.
Neisseria gonorrhoeae
All of the following are normal microbiota of the skin EXCEPT

Which region of the skin supports the largest bacterial population?
An eight-year-old girl has scabs and pus-filled vesicles on her face and throat. Three weeks earlier she had visited her grandmother, who had shingles. What infection does the eight-year-old have?
All of the following are characteristic of the Group A beta-hemolytic streptococci EXCEPT
M proteins.
hyaluronidase production.
the ability to dissolve blood clots.
the ability to damage cell membranes.

methicillin resistance
Thrush and vaginitis are caused by
Candida albicans.
All of the following are transmitted via the respiratory route EXCEPT

Koplik spots are a diagnostic indicator of
All of the following are characteristic of Pseudomonas aeruginosa EXCEPT
production of pyocyanin.
resistance to many types of disinfectants and antibiotics.
growth in moist environments.

gram-positive cell wall
Warts are caused by
Which of the following is NOT true of acne?
It can be treated by eliminating fatty foods from the diet.
Which of the following are incorrectly matched?
poxvirus fever blisters
Which of the following statements about congenital rubella syndrome is FALSE?
It does not occur with subclinical infections.
Why is vaccination for rubella recommended?
There is a high incidence of congenital infections and birth defects.
In which of the following respects is measles similar to German measles (rubella)?
They can be controlled by vaccination.
Exfoliative toxin is responsible for
scalded skin syndrome.
Staphylococcus aureus is responsible for all of the following EXCEPT

Which of the following is a subcutaneous mycosis?
A possible complication of chickenpox is
Which of the following cause(s) ringworm?
Microsporum and Epidermophyton
Scabies is transmitted by
Scabies is a skin disease caused by a
Which of the following is used to treat candidiasis of the skin or mucous membranes?
Which of the following is used to treat sporotrichosis?
potassium iodide
Which of the following is used to treat shingles?
The eradication of smallpox was possible because
there are no animal reservoirs of the virus.
Which of the following statements about Reye syndrome is FALSE?
Symptoms may include vomiting, drowsiness, or behavior changes.
It is a complication that may occur in chickenpox infection.
It is associated with aspirin use.
Prolonged neurological problems may occur.

It mostly affects older adults.
Which of the following is NOT caused by HSV-1?
canker sores
A patient has pus-filled vesicles and scabs on her face, throat, and lower back. She most likely has
Which of the following leads to all the others?
staphylococcal infection
Buruli ulcer is caused by
acid-fast bacteria.
The patient has a papular rash. Microscopic examination of skin scrapings reveals small eight-legged animals. The etiology is
The patient has vesicles and scabs over her forehead. Microscopic examination of skin scrapings shows gram-positive cocci in clusters. The etiology is
Staphylococcus aureus.
The patient has scaling skin on his fingers. Conidiospores are seen in microscopic examination of skin scrapings. The etiology is
A 45-year-old man has pus-filled vesicles distributed over his back in the upper right quadrant, over his right shoulder, and upper right quadrant of his chest. His symptoms are most likely due to
varicella-zoster virus.
A 35-year-old woman has a red, raised rash on the inside of her thighs. Gram-stained skin scrapings show large budding cells with pseudohyphae. The infection is caused by
Candida albicans.
Which of the following is likely to spread MRSA among athletes?
whirlpool baths
shared equipment
physical contact
taping gels

All of the answers are correct
A 17-year-old boy has pus-filled cysts on his face and upper back. Microscopic examination reveals gram-positive rods. This infection is caused by
Propionibacterium acnes.
Which of the following pairs is mismatched?
conjunctivitis – Chlamydia trachomatis
otitis externa – Pseudomonas
keratitis – Acanthamoeba
Buruli ulcer – Mycobacterium

chickenpox – poxvirus
Assume that your lab partner swabs the side of his face and uses the swab to inoculate a nutrient agar plate. The next day, he performs a Gram stain on the colonies. They are gram-positive cocci. You advise him that he should next look for
a coagulase reaction.
All of the following are causative agents of conjunctivitis EXCEPT
Haemophilus influenzae.
Neisseria gonorrhoeae.
Chlamydia trachomatis.

herpes simplex.
Newborns’ eyes are treated with an antibiotic
as a routine precaution.
The greatest single cause of blindness in the world is
Which of the following is used to treat herpetic keratitis?
Which of the following is incorrectly matched?
Acanthamoeba keratitis
Neisseria gonorrhea opthalmia neonatorum
Haemophilus influenzae pinkeye
Chlamydia trachomatis trachoma

Pseudomonas inclusion conjunctivitis