skin and soft tissue infections

Question 1

describe staph aureus and it’s virulence factor

Answer 1

gram positive, grape like clusters. panton valentine leukocidin toxin - punches holes in epithelium - marcophages migrate to here - these are then attacked and killed - tissue necrosis

Question 2

give examples of an infection caused by staph aureus

Answer 2

puss forming - impetigo, boils, surgical wound infections, endocarditis
toxin producing - endotoxin - toxic shock syndrome

Question 3

describe strep pyrogenes and give an example of an infection caused by it

Answer 3

gram positive cocci chains. superantigen - body over reacts to antigen, host response causes destruction. toxic shock syndrome, cellulitis

Question 4

describe streptococcus anginosous group and give an example of infection

Answer 4

gram positive chains, cytotoxin - intermedialysin, dental absess

Question 5

describe anaerobes and give an example of an infection

Answer 5

gram positive bacilli, lecithinase - lecthin is a fatty acid between membranes - attacked to allow spread of disease. necrotising fascitis

Question 6

describe candida albicans and give an example of infection

Answer 6

fungi - yeast cells and hyphae. phospholipase - breaks down phospholipids in cell membranes. candidiasis erythamtous

Question 7

give an example of an infection in the epidermis

Answer 7

impetigo - staph aureus

Question 8

give an example of an infection in the dermis

Answer 8

facial erysiplas - group a streptococcus

Question 9

give an example of an infection in the hair follicles

Answer 9

folliculitis - inflammation - staph aureus

boils - staph aureus deep seated, bottom of follicle, if many hair follicles involved - carbuncles

Question 10

give an example of an infection in subcutaneous fat

Answer 10

cellulitis - strep pyrogenes

Question 11

give an example of an infection in the fascia

Answer 11

nectrotising fascitis - anaerobes, staph aureus and strep pyrogenes

Question 12

give an example of an infection in the muscle

Answer 12

myonecrosis - gas gangrene and clostridium perfringes

Question 13

how are infections treated

Answer 13

diagnosis - need to know what is causing infection for treatment
surgical debridement - removal of tissue necrosis and puss - needs to be done but wont get to centre
antibiotics - kills microbes, can remove all bacteria but only if been debrided