7. Anaerobes and Peritonitis Flashcards
What infection is associated with intrauterine devices?
Actinomycosis
What features of an infection suggest that it may be caused by anaerobes?
Adjacent to mucosa Free gas Foul smell Not responding to gram positive antibiotics CNS manifestations
Why is particularly important to bring gram negative samples to the lab promptly?
They have been exposed to oxygen so will begin to die quickly
How do anaerobes inhibit phagocytosis?
Produce short chain fatty acids
What host factors can increase the risk of a gram negative infection?
Impaired gag or cough
Trauma and tissue ischaemia (so lack oxygen)
GI surgery
Amputation in a patient with peripheral vascular disease
Antibiotics
What are the symptoms of a clostridia tetani infection?
Muscle rigidity and spasms that last minutes, ongoing for 3-4 weeks
Exacerbated by noise, light and touch
What is the name of the neurotoxin produced by clostridia tetani?
Tetanospasm
Blocks inhibitory neurons
What type of vaccine is the tetanus vaccine?
Toxoid
What ways does clostridia tetani commonly enter the body?
Spores are introduced via skin trauma or on umbilical stump and germinate in the local anaerobic environment
May also contaminate heroin
How long is the incubation period for tetanus?
14 days
What does the muscle spasm appear like in tetanus?
Arm flexion
Leg extension
Back arch
Lockjaw
‘Risus sardonicus’ due to increased tone of orbicularis oris
May also cause laryngospasm and autonomic dysfunction
What can autonomic dysfunction cause in tetanus?
Arrhythmias
Sweating
What is the management for tetanus?
Early recognition essential, ABCs as may need to intubate
Treat infected source; debridement and metronidazole
Neutralise toxin with tetanus immunoglobulin
What effect does the botulinum toxin have?
Flaccid paralysis
Inhibits release of ACh at the neuromuscular junction
What are the types of botulinism?
Foodborne
Infant
Wound associated (including IVDU)