microbiology of dermatology

Question 1

what commensals should you not treat

Answer 1

staph epidermis, diphtheroid

Question 2

examples of common skin infections due to bacteria

Answer 2

boils and carbuncles, impetigo, infected eczema

Question 3

where is staph aureus found

Answer 3

on skin and mucous membranes

Question 4

how does staph aureus grow

Answer 4

best aerobically but can grow anaerobically

Question 5

examples of staph A virulence factors

Answer 5

capsule - antiphagocytic, fibrinogen binding system for adhesion and coagulase to clot plasma

Question 6

investigations for suspected staph A

Answer 6

swab +/- blood cultures

Question 7

management of normal staph A

Answer 7

flucoxacillin

Question 8

management of MRSA

Answer 8

doxycycline, vancomycin

Question 9

complications of staph A

Answer 9

toxic shock syndrome, panton-valentine leukocadin, scalded skin syndrome, enterotoxin

Question 10

what is the presentation of TSS

Answer 10

some strains release harmful toxins -> tocinoses
- diffuse macular rash, fever and hypotension

Question 11

what does panton- valentine leukocadin do

Answer 11

kills leukocytes

Question 12

what does enterotoxin cause

Answer 12

food poinoning

Question 13

what is strep pyogenes

Answer 13

group A strep

Question 14

where is strep pyogenes found

Answer 14

in throat but can adhere to skin

Question 15

group A strep haemolysis

Answer 15

beta heamolysis

Question 16

what can beta haemolysis cause

Answer 16

tissue/ cell destruction

Question 17

what classification system is used for serotyping surface antigen

Answer 17

lancefield system

Question 18

what protein antigens cause severe disease

Answer 18

M3 and M18

Question 19

what is the management of strep pyogenes infection

Answer 19

flucloxacillin

Question 20

complications of strep pyogene

Answer 20

necrotizing fascitis - type 2, toxic shock, cellulitis

Question 21

desrcibe necrotsing fascitis

Answer 21

invasive starins rapidly destroy connective tissue, life threatening and requires immediate surgical debridement

Question 22

how to treat leg ulcers

Answer 22

if no infection signs - no swabs and no antibiotics