Microbiology Chapter 21 Flashcards

Questions and Answers

All of the following are normal microbiota of the skin EXCEPT

Micrococcus

Staphylococcus

Corynebacterium

Propionibacterium

Streptococcus (correct)

What infection does the eight-year-old girl have?

Fever blisters

Measles

Chickenpox (correct)

Rubella

Scabies

Which of the following is NOT true of acne?

Antibiotics may be prescribed for moderate cases.

Mild cases are treated with topical agents.

Drugs that inhibit sebum formation are useful in treating inflammatory acne.

It can be treated by eliminating fatty foods from the diet. (correct)

It is often due to the action of Propionibacterium.

Warts are caused by

Papillomavirus Signup and view all the answers

All of the following are characteristic of Pseudomonas aeruginosa EXCEPT

Gram-positive cell wall Signup and view all the answers

Koplik spots are a diagnostic indicator of

Measles Signup and view all the answers

All of the following are transmitted via the respiratory route EXCEPT

Tinea Signup and view all the answers

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

Pyocyanin production Signup and view all the answers

Thrush and vaginitis are caused by

Candida albicans Signup and view all the answers

The greatest single cause of blindness in the world is

Trachoma Signup and view all the answers

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

Methicillin resistance Signup and view all the answers

Which of the following cause(s) ringworm?

Microsporum and Epidermophyton Signup and view all the answers

Newborns' eyes are treated with an antibiotic

As a routine precaution Signup and view all the answers

A possible complication of chickenpox is

Encephalitis Signup and view all the answers

Which of the following is a subcutaneous mycosis?

Sporotrichosis Signup and view all the answers

Which region of the skin supports the largest bacterial population?

Armpits Signup and view all the answers

Staphylococcus aureus is responsible for all of the following EXCEPT

Acne Signup and view all the answers

Exfoliative toxin is responsible for

Scalded skin syndrome Signup and view all the answers

All of the following are causative agents of conjunctivitis EXCEPT

Herpes simplex Signup and view all the answers

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

They can be controlled by vaccination Signup and view all the answers

Why is vaccination for rubella recommended?

There is a high incidence of congenital infections and birth defects Signup and view all the answers

Which of the following statements about congenital rubella syndrome is FALSE?

It does not occur with subclinical infections Signup and view all the answers

Which of the following are incorrectly matched?

Poxvirus — fever blisters Signup and view all the answers

Which of the following is NOT caused by HSV-1?

Canker sores Signup and view all the answers

Which of the following statements about Reye syndrome is FALSE?

It mostly affects older adults Signup and view all the answers

The eradication of smallpox was possible because

There are no animal reservoirs of the virus Signup and view all the answers

Which of the following is used to treat herpetic keratitis?

Trifluridine Signup and view all the answers

Which of the following is used to treat shingles?

Penicillin Signup and view all the answers

Which of the following is used to treat sporotrichosis?

Potassium iodide Signup and view all the answers

Which of the following is used to treat candidiasis of the skin or mucous membranes?

Miconazole Signup and view all the answers

Scabies is a skin disease caused by a

Mite Signup and view all the answers

Scabies is transmitted by

Fomites Signup and view all the answers

A patient has pus-filled vesicles and scabs on her face, throat, and lower back. She most likely has

Chickenpox Signup and view all the answers

Which of the following leads to all the others?

Staphylococcal infection Signup and view all the answers

Buruli ulcer is caused by

Acid-fast bacteria Signup and view all the answers

The patient has a papular rash. Microscopic examination of skin scrapings reveals small eight-legged animals. The etiology is

Sarcoptes Signup and view all the answers

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 Signup and view all the answers

The patient has scaling skin on his fingers. Conidiospores are seen in microscopic examination of skin scrapings. The etiology is

Microsporum Signup and view all the answers

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 Signup and view all the answers

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 Signup and view all the answers

Which of the following is incorrectly matched?

Pseudomonas — inclusion conjunctivitis Signup and view all the answers

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 Signup and view all the answers

Which of the following pairs is mismatched?

Chickenpox — poxvirus Signup and view all the answers

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 Signup and view all the answers

Which of the following is likely to spread MRSA among athletes?

All of the answers are correct Signup and view all the answers

Study Notes

Normal Microbiota and Infections

Not all skin microbiota are beneficial; Streptococcus is not a normal skin inhabitant.
Chickenpox can result from exposure to varicella-zoster virus, particularly after contact with someone who has shingles.

Acne and Skin Conditions

Acne is primarily caused by Propionibacterium; dietary fat reduction is ineffective in treatment.
Warts are caused by papillomavirus, a common viral infection in humans.

Characteristics of Pseudomonas aeruginosa

Pseudomonas aeruginosa is notable for its production of pyocyanin, rod-shaped structure, and ability to resist disinfectants; it is not gram-positive.

Diagnosing Infections

Koplik spots indicate measles infection, a critical diagnostic sign.
Respiratory route infections include smallpox, measles, rubella, and chickenpox, but tinea (ringworm) does not spread this way.

Skin Protection and Microbial Infections

The skin's protective factors include tightly packed cells, salt, keratin, and lysozyme; pyocyanin production is not a protective mechanism.
Candida albicans causes conditions such as thrush and vaginitis.

Eye Infections

Trachoma is the leading cause of blindness globally, often resulting from repeated conjunctivitis.
Newborns receive antibiotic eye treatments as a routine precaution against infections.

Complications and Treatments

A complication of chickenpox is encephalitis.
Sporotrichosis is a type of subcutaneous mycosis, treatable with potassium iodide.

Specific Skin Conditions

The armpits sustain the highest bacterial populations on the skin.
Staphylococcus aureus can cause serious infections; however, it is not responsible for acne.

Disease Causes and Diagnosis

Exfoliative toxin leads to scalded skin syndrome, a severe skin condition in children.
HSV-1 is responsible for conditions like cold sores and herpes gladiatorum, but canker sores are not attributed to it.

Vaccination and Infection Prevention

Vaccination for rubella is recommended to prevent serious congenital infections and defects in newborns.
Congenital rubella syndrome can lead to severe fetal complications like deafness and blindness.

Mismatched Infections

Chickenpox is specifically caused by varicella-zoster virus, not poxvirus.
MRSA spreads among athletes through physical contact and shared equipment, highlighting the importance of hygiene.

Identifying Causative Agents

Specific infections are diagnosed based on the presence of characteristic organisms, such as Microsporum causing skin conditions and Propionibacterium acnes leading to acne.

Additional Key Facts

Buruli ulcer is attributed to acid-fast bacteria, specifically recognized as Mycobacterium ulcerans.
A gram-positive reaction would prompt further tests for coagulase to identify Staphylococcus species in cases of skin infections.

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Description

Test your knowledge on skin microbiota and infections with these flashcards from Microbiology Chapter 21. Explore various organisms and disease processes to enhance your understanding of microbial interactions in human health.