Anaerobic Bacteria Infections

Question 1

Clostridia

are what kind of bacteria?

Answer 1

spore forming, anaerobic rods

Question 2

Clostridia

what are clostridial disorders?

Answer 2

Botulism, tetanus, gas gangrene, c diff

Question 3

Clostridia

what spp cause the most potent biological toxins for humans?

Answer 3

C botulinum & C tetani

Question 4

Clostridium botulinum

What is botulism?

and what’s the pathophysiology?

Answer 4

a paralytic disease caused by the toxin from Clostridium botulinum

Toxin prevents release of acetylcholine at neuromuscular junctions and autonomic synapses

Question 5

Clostridium botulinum

what are the three forms of botulism?

Answer 5

1. Food-borne botulism
   Canned, smoked, or vacuum-packed food
2. “wound botulism”
   Often seen with Injectable drug use
3. Infant botulism
   Ingestion of honey

Question 6

Clostridium botulinum

what are the signs and symptoms of infection?

Answer 6

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

Question 7

what is the first sign of Infant Botulism, and why does this happen?

Answer 7

first sign can be constipation

incompletely-developed intestinal flora may be to blame

Question 8

Botulism

How to be Dx?

Answer 8

Analysis of serum, stool, gastric contents or food for toxin
May consider electrophysiologic studies

Question 9

Botulism

How do we treat infection?

Answer 9

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

Question 10

Clostridium tetani

produces what toxin and how does it work?

Answer 10

tetanospasmin which interferes with neurotransmission at spinal synapses of inhibitory neurons

minor stimuli=uncontrolled spasm
reflexes are exaggerated

Question 11

Tetanus

how long is incubation?

Answer 11

8-12 days

Question 12

Tetanus

What are the signs and symptoms of early infection?

Answer 12

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

Question 13

Tetanus

what are LATER signs and symptoms of infection?

Answer 13

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

Question 14

Tetanus

How do we Dx?

Answer 14

Dx is clinical, there are no labs.

Question 15

Tetanus

how do we treat?

Answer 15

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

Question 16

Tetanus

what is the prognosis?

Answer 16

high mortality with rapid onset and delayed care
spasm for 3-4 weeks
complete recovery may take months.

toxin binding is irreversible

Question 17

Tetanus

How can we prevent infection?

Answer 17

natural infection does not result in immunity

immunization

Question 18

what disease does Clostridial myonecrosis cause?

Answer 18

gas gangrene

Question 19

Clostridial myonecrosis

What is gas gangrene?

Answer 19

Commonly due to trauma or injection drug use
Toxins produced in affected tissue lead to shock, hemolysis, and tissue necrosis

Question 20

What spp cause clostridial myonecrosis?

Answer 20

Produced by multiple clostridia (C perfringens amongst many)

Question 21

gas gangrene

what are signs and symptoms of sudden onset infection?

Answer 21

Sudden onset
Rapidly worsening pain
Hypotension
Tachycardia
Fever but not proportionate to severe infection
delirium

Question 22

gas gangrene

what are the signs and symptoms of affected wounds?

Answer 22

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

Question 23

Gas gangrene

How to we treat?

Answer 23

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

Question 24

gas gangrene

How do we Dx?

Answer 24

Diagnosis is clinical
X-ray may show gas within soft tissue
Anaerobic culture confirms diagnosis

Question 25

C. Difficile colitis is associated with what populations?

Answer 25

antibiotic use, geriatric, immunocompromised

Question 26

# C diff how long after antibtiotics does infection arise?

Answer 26

up to 8 weeks after antibiotic use

Question 27

# c Diff what antibiotics are likely to cause infection?

Answer 27

**fluoroquinolones** clindamycin beta-lactams

Question 28

# C diff What are signs and symptoms?

Answer 28

Greenish, foul, watery diarrhea 5–15 x daily Mild LLQ tenderness Sever/fulminant disease

Question 29

# C diff Severe and sudden/fulminant disease Sx

Answer 29

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

Question 30

# C diff How do we Dx?

Answer 30

Stool toxin/antigen assay non-contrast abd CT scan sever/fulminant to look for colonic dilation and wall thickening

Question 31

# C diff What are complications of infection?

Answer 31

Hemodynamic instability Respiratory failure due to metabolic acidosis Metabolic acidosis Megacolon (>7cm) Perforation Death

Question 32

# C diff How do we treat?

Answer 32

Complex antibiotic decision tree Prevention: minimize antibiotic use don’t suppress gastric acid Contact precautions in facilities Call infectious disease

Question 33

# Corynebacterium diphtheriae What is diptheria?

Answer 33

Acute infection caused by Corynebacterium diphtheriae Nasal, laryngeal, pharyngeal, and cutaneous forms Spread by respiratory secretions Exotoxin responsible for myocarditis and neuropathy

Question 34

# Diptheria What are the complications of infection?

Answer 34

Myocarditis Arrhythmia, heart block, heart failure Neuropathy Cranial nerves (diplopia, slurred speech, dysphagia)

Question 35

# Diptheria How do we Dx?

Answer 35

Clinical diagnosis Can confirm with + culture for C. diphtheriae 

Question 36

# Diptheria How do we treat?

Answer 36

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 Antitoxin given with any suspicion Erythromycin 500mg 4x a day 14 days

Question 37

# Diptheria How do we prevent infection? after exposure?

Answer 37

childhood vaccine series adults tdap booster indicated with exposure erythromycin 500mg 4x for 7 days if exposed to someone infected.