Lecture 11 - Staph Aureus

Question 1

Gram Positive?

Answer 1

Has thick peptidoglycan cell wall that stains purple

Question 2

Animal disease?

Answer 2

Bovine mastitis - infection of dairy mammaries

Question 3

Colonisation?

Answer 3

20-25% at one time, 10-15% persistent carriers

Question 4

Diseases?

Answer 4

60% asymptomatic, food poisoning common, skin infection 3%, serious disease 1 in 5000

Question 5

Infection?

Answer 5

staph on skin invades sweat gland, replicate and damage epithelial cells, damaged cells release cytokines causing capillary opening & chemotaxis as well as pain & swelling

Question 6

Masking and indiacation of Staph?

Answer 6

Protein A on cell surface binds heavy chain of IgG; Ig bound by light chains trigger the immune response

Question 7

Staph survival techniques?

Answer 7

coat in antibodies to avoid detection/phagocytosis, release CHIPS to prevent chemotaxis, use catalase to counter hydrogen peroxide inside neutrophil, release neutrophil destroying toxins

Question 8

Treatment?

Answer 8

stabilise person, drain pus, antibiotics