ID-Skin

Question 1

Skin defenses

Answer 1

Constant sloughing off of cells from the stratum corneum (surface), antimicrobial substances including sebum, sweat, and amino acids.

Question 2

Normal biota of the skin

Answer 2

Must be able to live in dry, salty conditions and fend for themselves. Microbes grow in dense populations in moist areas and skin folds or in hair follicules and glandular ducts.

Question 3

3 main categories of normal skin biota

Answer 3

Diptheroids, micrococci, yeasts

Question 4

Impetigo

Answer 4

Superficial bacterial infection that causes the skin to flake or peel off. This is HIGHLY contagious and usually seen in children. It is caused either by staphylococcus auereus or streptococcus pyogenes. It looks like peeling skin, crusty and flaky scabs, or honey colored crusts. Also pustules filled with honey colored pus. Lesions are usually found around the mouth, face, and extremities. Itchy.

Question 5

Impetigo caused by Staphylococcus aureus

Answer 5

Finely tuned to cause disease in humans. Grows well and most people carry this as normal flora unless it travels to other areas in which it is damaging. Gram positive, non motile, grows from 10-46 C, and grows with and without oxygen (facultative anaerobe).

Question 6

Impetigo virulence factors

Answer 6

Produces endotoxins a and b, produces coagulase enzyme, and produces other toxins such as Hyeluronidase and Staphylokinase.

Question 7

Detection of Impetigo caused by Staph auerus

Answer 7

First step is coagulase test, second is catalase.

Question 8

Transmission of impetigo

Answer 8

Highy contagious and transmitted by direct contact. Peak incidence is in summer and fall due to more contact with people.

Question 9

Prevention of impetigo

Answer 9

Good hygiene and vaccine is in development

Question 10

Treatment of impetigo

Answer 10

Treated with any antibiotic that will kill staphylococcus. Drug of choice is topical mupirocen. Some oral antibiotics may be used in case of wide spread skin involvement.