INFECTIOUS DISEASES

Question 1

If an individual is allergic to penicillin and they have been diagnosed with cellulitis, what other antibiotics can you give?

Answer 1

Clarithromycin, Erythromycin in pregnancy or doxycycline

Question 2

What is the organisms most responsible for cellulitis?

Answer 2

Infection with Streptococcus Pyogenes or less commonly Staphylococcus Aureus

Question 3

Pseudomonas Aeruginosa

Describe 3 lab features of pseudomonas aeruginosa and how can they present on a wound?

Answer 3

Lab features suggestive of Pseudomonas aeruginosa include:
1. Aerobic Gram-negative rod
2. non-lactose fermenting
3. oxidase positive

Wounds contaminated with pseudomonas aueroginosa- Classically presents with GREEN EXUDATE and STRONG SMELL
Diabetics-increased risk and therefore vascular wounds frequently contaminated with this

Question 4

Pseudomonas Aueroginosa

Describe the clinical infections that can be caused by pseudomonas auerginosa and the pathophysiology behind it?

Answer 4

chest infections (especially in cystic fibrosis)
skin: burns, wound infections, ‘hot tub’ folliculitis
otitis externa (especially in diabetics who may develop malignant otitis externa)
urinary tract infections

Pathophysiology:
produces both an endotoxin (causes fever and shock) and exotoxin A

Question 5

E.coli

Describe lab features of E.Coli that is different from Pseudomonas Aueriginosa?

Answer 5

Gram negative rod but IS LACTOSE FERMENTING- often linked to GI or UTI infection (atypical for skin)

Question 6

Neisseria Meningitidis

Describe the lab features of N.Meningitidis?

Answer 6

• Gram negatice
• Oxidase +
• NON LACTOSE FERMENTING
• Dipplococcus bacteria (not rod)
• Linked to meningitis and septicaemia

Question 7

Lab findings of S.Aureus and Strep.Pyogenes?

Answer 7

Gram + Cocci