Infectious Diseases - Diphtheria and Clostridium Flashcards
What does Diphtheria look like under the microscope?
Gram positive bacilli
Unencapsulated
Non motile
Non sporulating
Form clusters or parallel rays
What is Diphtheria Toxin?
Produced by toxin Positive Diphtheria strains
Produced in pseudomembrane then internalised, and the A fragment then binds to irreversibly inhibit protein synthesis
What are the clinical presentations of Diphtheria?
Pharyngitis
- adherent pseudomembranous lesions
- “BULL NECK” with massive tonsillar swelling, foul breath and strider
Neurotoxicity
Arrythmias and heart failure
Features of the polyneuropathy seen with Diphtheria?
- occurs 3-5 WEEKS post onset
- severe and prolonged
Typically involve mouth and neck
- lingual/face numbness
- dysphonia
- cranial nerve palsy
Later develop motor and sensory in peripheries
Also commonly autonomic instability
IF SURVIVE THEN IS USUALLY REVERSIBLE
Treatment of Diphtheria?
Diphtheria antitoxin ASAP
Penicillin G or Erythromycin
What does clostridium look like under the microscope?
Rod shaped
Spore forming
In clostridium infections what toxins cause gas gangrene?
Alpha and omega toxins
Features of clostridium gastro
- usually poorly cooked meat with residual spores
- incubation 7 - 30 hours
- mild and self limited
Features of clostridium enteritis necroticans and clostridium necrotising enterocolitis
Enteritis Necroticans
- extensive bowel wall necrosis
- due to alpha toxin and beta toxin producing strains
Necrotising Enterocolitis
- resembles enteritis necroticans
- intestinal ‘gas cysts’
Incubation of clostridium gas gangrene?
6 hours
Spontaneous clostridium gas gangrene can occur in which conditions?
- IBD
- Colonic malignancy
- Diverticulitis
Effect of clostridium ALPHA and OMEGA toxin on heart
Alpha toxin suppresses myocardial contractility
Omega toxin reduces systemic vascular resistance and INCREASES cardiac output
Treatment of clostridium infections?
Clindamycin
