Anaerobic Bacteria Infections Flashcards
Clostridia
are what kind of bacteria?
spore forming, anaerobic rods
Clostridia
what are clostridial disorders?
Botulism, tetanus, gas gangrene, c diff
Clostridia
what spp cause the most potent biological toxins for humans?
C botulinum & C tetani
Clostridium botulinum
What is botulism?
and what’s the pathophysiology?
a paralytic disease caused by the toxin from Clostridium botulinum
Toxin prevents release of acetylcholine at neuromuscular junctions and autonomic synapses
Clostridium botulinum
what are the three forms of botulism?
- Food-borne botulism
Canned, smoked, or vacuum-packed food - “wound botulism”
Often seen with Injectable drug use - Infant botulism
Ingestion of honey
Clostridium botulinum
what are the signs and symptoms of infection?
Within 12-36 hours
Diplopia
Loss of accommodation
Ptosis
Impairment of extraocular muscles
Pupils are fixed and dilated
dry mouth
Dysphagia- cant swallow
dysphonia - vocal chord muscles don’t work
Descending symmetrical paralysis of voluntary muscles. Can progress to respiratory failure, death without mechanical assistance
Tendon reflexes are typically intact
normal sensory examination
what is the first sign of Infant Botulism, and why does this happen?
first sign can be constipation
incompletely-developed intestinal flora may be to blame
Botulism
How to be Dx?
Analysis of serum, stool, gastric contents or food for toxin
May consider electrophysiologic studies
Botulism
How do we treat infection?
Hospitilaztion
antitoxin given ASAP- avoid w horse serum allergy
Immunoglobulin for infants (BABYBIG)
resp failure managed with intubation/mechanical ventilation
Notify State health authorities/CDC at first suspicion
Clostridium tetani
produces what toxin and how does it work?
tetanospasmin which interferes with neurotransmission at spinal synapses of inhibitory neurons
minor stimuli=uncontrolled spasm
reflexes are exaggerated
Tetanus
how long is incubation?
8-12 days
Tetanus
What are the signs and symptoms of early infection?
Patient remains awake and alert throughout
Pain at wound site
Spasticity of regional muscles
Jaw muscle stiffness (“lock jaw”)
Stiffness of the neck and other muscles
Dysphagia
Irritability
Tetanus
what are LATER signs and symptoms of infection?
Hyperreflexia
Spasms of Jaw muscles (trismus) or facial muscles
Rigidity and spasms of abdomen, neck, and back
painful tonic convulsions precipitated by minimal stimuli
May have asphyxia if spasms of glottis/respiratory muscles
Tetanus
How do we Dx?
Dx is clinical, there are no labs.
Tetanus
how do we treat?
Human tetanus immune globulin 500 units IM within 24 hours of presentation
Wound debridement
Metronidazole(Flagyl) 7.5 mg/kg IV/PO every 6 hours for 7-10 days
bed rest and quietest conditions possible
Sedation, paralysis, and mechanical ventilation often needed
Tetanus
what is the prognosis?
high mortality with rapid onset and delayed care
spasm for 3-4 weeks
complete recovery may take months.
toxin binding is irreversible
Tetanus
How can we prevent infection?
natural infection does not result in immunity
immunization
what disease does Clostridial myonecrosis cause?
gas gangrene
Clostridial myonecrosis
What is gas gangrene?
Commonly due to trauma or injection drug use
Toxins produced in affected tissue lead to shock, hemolysis, and tissue necrosis
What spp cause clostridial myonecrosis?
Produced by multiple clostridia (C perfringens amongst many)
gas gangrene
what are signs and symptoms of sudden onset infection?
Sudden onset
Rapidly worsening pain
Hypotension
Tachycardia
Fever but not proportionate to severe infection
delirium
gas gangrene
what are the signs and symptoms of affected wounds?
Swelling
Pallor around wound
Foul smelling brown, blood-tinged serous drainage
almond smell
Later
Skin turns dusky then deeply discolored
Red fluid filled vesicles
Gas may be palpable in tissue
Gas gangrene
How to we treat?
Surgical debridement
Penicillin 2 million units every 3 hours
AND
Clindamycin 600-900mg IV every 8 hours
Clindamycin may decrease bacterial toxin production.
benefit from O2 chamber therapy
gas gangrene
How do we Dx?
Diagnosis is clinical
X-ray may show gas within soft tissue
Anaerobic culture confirms diagnosis
C. Difficile colitis is associated with what populations?
antibiotic use, geriatric, immunocompromised
C diff
how long after antibtiotics does infection arise?
up to 8 weeks after antibiotic use
c Diff
what antibiotics are likely to cause infection?
fluoroquinolones
clindamycin
beta-lactams
C diff
What are signs and symptoms?
Greenish, foul, watery diarrhea 5–15 x daily
Mild LLQ tenderness
Sever/fulminant disease
C diff
Severe and sudden/fulminant disease Sx
profuse diarrhea (≥ 30 stools/day)
Fever
hemodynamic instability
abdominal distention/pain
Labs = WBC >30,000, albumin < 2.5 (due to protein-losing enteropathy), elevated serum lactate, rising Cr
C diff
How do we Dx?
Stool toxin/antigen assay
non-contrast abd CT scan sever/fulminant to look for colonic dilation and wall thickening
C diff
What are complications of infection?
Hemodynamic instability
Respiratory failure due to metabolic acidosis
Metabolic acidosis
Megacolon (>7cm)
Perforation
Death
C diff
How do we treat?
Complex antibiotic decision tree
Prevention:
minimize antibiotic use
don’t suppress gastric acid
Contact precautions in facilities
Call infectious disease
Corynebacterium diphtheriae
What is diptheria?
Acute infection caused by Corynebacterium diphtheriae
Nasal, laryngeal, pharyngeal, and cutaneous forms
Spread by respiratory secretions
Exotoxin responsible for myocarditis and neuropathy
Diptheria
What are the complications of infection?
Myocarditis
Arrhythmia, heart block, heart failure
Neuropathy
Cranial nerves (diplopia, slurred speech, dysphagia)
Diptheria
How do we Dx?
Clinical diagnosis
Can confirm with + culture for C. diphtheriae
Diptheria
How do we treat?
Careful airway management
Removal of membrane by laryngoscopy or bronchoscopy
potential for dislodging pseudomembrane
Intubation may protect airway (airway edema and mucosal friability)
Respiratory droplet isolation until 3 consecutive negative cultures
Antitoxingiven with any suspicion
Erythromycin 500mg 4x a day 14 days
Diptheria
How do we prevent infection?
after exposure?
childhood vaccine series
adults tdap
booster indicated with exposure
erythromycin 500mg 4x for 7 days if exposed to someone infected.
