S11 L1 - Streptococci incl. pharyngitis, acute rheumatic fever, scarlet fever, toxic shock syndrome, skin conditions, EBV

Question 1

Streptococci
- Classifying streptococci via there haemolytic properties
(3)

Answer 1

Question 2

• *Streptococcus pyogenes**
• Virulence factors

Answer 2

Question 3

• *Streptococcus Phrangitis - aka Strep throat**
• Age
• How does it spread
• Symptoms
• Usually no need for antibiotics

Answer 3

• Age: Children 5-15 yrs
• How does it spread: Droplet spread
• Symptoms: Sore throat and then malaise, fever, headache, swelling of the tonsils
• Usually no need for antibiotics, because:
• – Important for the patient to develop an antibody to M protein giving them immunity to group A streptococci
• Antibiotics may not increase time of recovery
• Antibiotic resistance

Question 4

• *Scarlet fever**
• Why might this develop?
• Symptoms

Answer 4

If the strain also contains pyrogenic exotoxins, the streptococcal pharyngitis can develop into scarlet fever
- characteristic rash
- fever
(caused by the action of the toxins)
Antibiotics are required!

Question 5

Complications of Streptococcus pharyngitis

Answer 5

• *Complications of Streptococcal pharyngitis:
• Acute Rheumatic fever:**caused by binding of the M protein to the host’s collagen or auto-immune after group Strep. A infection. Can manifests up to 3 weeks after initial pharyngitis, can also affect different parts of the body including brain, heart, joints, skin
• *-** Acute Post-Streptococcal Glomerulonephritis: is inflammation of the glomeruli, which are structures in your kidneys that are made up of tiny blood vessels. M type specific but not the same as the ones that can cause ARF.
• *-** **Brain abscess
• Meningitis
• Sinusitis
• Peritonsillar cellulitis**

Antibiotics are required!

Question 6

Toxic shock syndrome

Answer 6

- Toxic shock syndrome: Very serious reaction – caused by exotoxin released by the bacteria triggering T cells to give a non-specific systemic inflammatory response, leading to vascular collapse
Bacteria enters the bloodstream after a deep tissue infection, quickly progresses into bacteraemia, vascular collapse and then organ failure
– progresses v quickly – dead in hrs

Question 7

• *Streptococcus Pyogenes skin conditions**
• List some that it can cause

Answer 7

Question 8

• *Epstein-Barr Virus (EBV)**
• Pathogen
• Patient
• Mechanism of infection
• Infection - pathophysiology

Answer 8