streptococcus

Question 1

what type of bacteria are streptococci?

Answer 1

gram positive chains of cocci

Question 2

what are the different classes of streptococci?

Answer 2

1. pyogenic - puss producing
2. viridans - bacteria that dont fall into other categories
3. enterococcal - bile tolerant, penicillin ressitant + gut dwelling
4. lactic - bacteria from dairy source

Question 3

where does streptococcus pyogenes normally colonise?

Answer 3

throat
genital mucosa
rectum
skin

Question 4

what is the main virulence factors of streptococcus pyogenes?

Answer 4

surface M protein - plays a role in adherence to epithelial cells and means that bacteria is resistant to phagocytosis

Question 5

which infections are caused by strep pyogenes?

Answer 5

• pharyngitis or strep throat (spread by droplets)
• skin conditions e.g. cellulitis
• streptococcus toxic shock syndrome – often fatal - deep tissue infection with strep pyogenes AND bacteraemia AND vascular collapse AND organ failure - From health to death in hours

Question 6

what are secondary complications associated with strep pyogenes infection?

Answer 6

scarlet fever
abscesses of head and neck
rheumatic fever
glomerulonephritis