Question 1

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?

Accepted Answer

The symptoms of scabs and pus-filled vesicles on the face and throat are indicative of chickenpox. This is especially likely given that the child had recently been in contact with someone who had shingles, which is caused by the same virus as chickenpox.

Question 2

Exfoliative toxin is responsible for

Accepted Answer

Exfoliative toxin is responsible for scalded skin syndrome, a condition in which the skin becomes red and blistered and then peels off in sheets. It is caused by Staphylococcus aureus bacteria.

Question 3

Staphylococcus aureus is responsible for all of the following EXCEPT

Accepted Answer

Staphylococcus aureus can cause a variety of skin infections, including pimples, sties, boils, and carbuncles. However, acne is not typically caused by S. aureus, but rather by other types of bacteria and inflammatory factors.

Question 4

Newborns' eyes are treated with an antibiotic

Accepted Answer

Newborns' eyes are routinely treated with an antibiotic to prevent infections such as gonococcal ophthalmia neonatorum, regardless of the mother's infection status.

Question 5

Which of the following is NOT true of acne?

Accepted Answer

While diet is known to play a role in overall skin health, there is no clear evidence that eliminating fatty foods from the diet treats acne. Therefore, option A is not true.

Question 6

Which region of the skin supports the largest bacterial population?

Accepted Answer

The armpits have a dense concentration of sweat glands and hair follicles, which provide a favorable environment for bacterial growth. This area also tends to be warm and moist, which further supports bacterial proliferation. Therefore, the armpits support the largest bacterial population compared to the other regions listed.

Question 7

All of the following are normal microbiota of the skin EXCEPT

Accepted Answer

Streptococcus is not a normal microbiota of the skin. However, it is commonly found in the respiratory and gastrointestinal tracts. The other choices are all normal microbiota of the skin.

Question 8

Thrush and vaginitis are caused by

Accepted Answer

Thrush and vaginitis are both caused by Candida albicans, a type of yeast. Herpesvirus, Chlamydia trachomatis, Staphylococcus aureus, and Streptococcus pyogenes can all cause different types of infections, but not thrush or vaginitis.

Question 9

All of the following are causative agents of conjunctivitis EXCEPT

Accepted Answer

All of the listed organisms can cause conjunctivitis except for herpes simplex, which causes a keratitis (inflammation of the cornea).

Question 10

A possible complication of chickenpox is

Accepted Answer

Encephalitis, an inflammation of the brain, can occur as a complication of chickenpox, especially in adults or those with weakened immune systems.

Question 11

All of the following are characteristic of the Group A beta-hemolytic streptococci EXCEPT

Accepted Answer

Group A beta-hemolytic streptococci are generally susceptible to methicillin, and therefore do not exhibit methicillin resistance. The other options are characteristic features of Group A streptococci.

Question 12

Koplik spots are a diagnostic indicator of

Accepted Answer

Koplik spots are small red spots with blue-white centers that appear inside the mouth and on the inner lining of the cheeks in the early stages of measles infection. Therefore, the correct option is E - measles.

Question 13

All of the following are characteristic of Pseudomonas aeruginosa EXCEPT

Accepted Answer

Pseudomonas aeruginosa is a gram-negative bacterium, not gram-positive. All the other characteristics mentioned are true for P. aeruginosa.

Question 14

Which of the following cause(s)ringworm?

Accepted Answer

Microsporum and Epidermophyton are both types of fungi that can cause ringworm infections in humans and animals. Mycobacterium is a type of bacteria that is not associated with ringworm.

Question 15

In which of the following respects is measles similar to German measles (rubella)?

Accepted Answer

The answer of In which of the following respects is...

Question 16

The greatest single cause of blindness in the world is

Accepted Answer

Trachoma is a bacterial eye infection caused by Chlamydia trachomatis that can lead to scarring of the eyelid and cornea, resulting in blindness. It is the leading cause of preventable blindness worldwide, affecting millions of people in developing countries with poor sanitation and limited access to healthcare. Neonatal gonorrheal ophthalmia, keratoconjunctivitis, inclusion conjunctivitis, and pinkeye are all types of eye infections that can cause damage and vision loss, but they are not as common or severe as trachoma.

Question 17

All of the following are protective factors of the skin and its secretions EXCEPT

Accepted Answer

Pyocyanin production is not a protective factor of the skin and its secretions. In fact, pyocyanin is a pigment produced by certain bacteria, including Pseudomonas aeruginosa, which can cause infections in the skin and other parts of the body. The other choices, keratin, tightly packed cells, lysozyme production, and salt, all contribute to the protective function of the skin and its secretions.

Question 18

All of the following are transmitted via the respiratory route EXCEPT

Accepted Answer

Tinea (ringworm) is a fungal skin infection that is not transmitted via the respiratory route. The other options listed are all viral infections that can be spread through respiratory secretions.

Question 19

Warts are caused by

Accepted Answer

Warts are caused by the human papillomavirus (HPV).

Question 20

Which of the following is a subcutaneous mycosis?

Accepted Answer

Subcutaneous mycoses are fungal infections that involve the dermis, subcutaneous tissues, and sometimes muscle. Sporotrichosis is a subcutaneous mycosis caused by the fungus Sporothrix schenckii. The other options listed are not subcutaneous mycoses: tinea capitis is a fungal infection of the scalp, erysipelas is a bacterial skin infection, athlete's foot is a fungal infection of the feet, and Buruli ulcer is a bacterial infection that affects the skin and subcutaneous tissue.

Quiz 21: Microbial Diseases of the Skin and Eyes