Anaerobic Bacterial Infections Flashcards
(62 cards)
1
Q
Clostridia
what type of anaerobic rods are these?
A
spore forming
2
Q
Clostridia
which two Clostridia are the two most potent biological toxins known to humans?
A
- botulinum
- tetani
3
Q
Clostridia
4 different disorders
A
- botulism
- tetanus
- gas gangrene
- c. diff
4
Q
Clostridium botulinum
3 types
A
- foodborne
- wound (not as common as the others)
- infant
5
Q
Clostridium botulinum
what is associated w/ foodborne bot?
A
canning, smoking, vaccuum packing food
6
Q
Clostridium botulinum
what is associated with wound bot?
A
IV drug use
7
Q
Clostridium botulinum
what is seen with infant bot?
A
honey ingestion
8
Q
Clostridium botulinum
what does bot toxin do?
A
paralysis
9
Q
Clostridium botulinum
how does bot toxin cause paralysis?
A
prevents release of ACH at neuromuscular junctions and autonomic synapses
10
Q
Clostridium botulinum
signs and sx
8 components
A
- development of sudden, fluctuating, severe weakness w/ intact sensation
- diplopia, loss of accomodation, ptosis, impairment of extraocular muscles, pupils fixed/dilated
- dry mouth
- dysphagia
- dysphonia
- symmetrical paralysis that is descending
- tendon reflexes in tact
- normal sensory exam
11
Q
Clostridium botulinum
why are infants more susceptible to spores that wouldn’t typically make adults ill?
Infant Bot
A
incompletely developed intestinal flora
12
Q
Clostridium botulinum
first sign of infant bot? followed by?
A
- constipation
- lethargy, poor feeding
13
Q
Clostridium botulinum
Dx
A
- notify PH/CDC at first suspicion
- analysis of serum, stool, gastric contents
- consider electrophysiologic studies
14
Q
Clostridium botulinum
Tx
5 things
A
- anti-toxin
- give before confirmation if suspicions are high enough
- must be released by PH
- hospitalize pt ASAP
- intubation/mech vent if respiratory failure occured
15
Q
Clostridium botulinum
Antitoxin contraindication
A
horse serum allergy
16
Q
Clostridium botulinum
what do you give for infant bot?
A
babybig (bot immunoglobin)
17
Q
Clostridium tetani
pathophys
A
- produces neurotoxin tetanospasmin
- interferes with neurotransmission at spinal synapses of inhibitory neurons
18
Q
Clostridium tetani
incubation period
A
8-12 days
19
Q
Clostridium tetani
at risk population
A
unvax people
20
Q
Clostridium tetani
initial signs & sx
A
- pt remains awake/alert
- pain at wound site
- spasticity of regional muscles
- jaw muscle stiffness
- stiffness of neck/other muscles
- dysphagia
- irritability
21
Q
Clostridium tetani
later signs & sx
A
- hyperreflexia
- spasm of jaw or facial muscles
- rigidity and spasms of abdomen/neck/back
- painful tonic convulsions precipitated by minimal stimuli
- asphyxia if pumlp spasms
22
Q
Clostridium tetani
dx
A
clinical observation
23
Q
Clostridium tetani
tx
A
- human tetanus immuneglobin 500 units, IM
- wound debridement
- Metrondiazole, 7.5 mg/kg IV/PO, Q6 hrs, 7-10 days
- bed rest
- sedation, paralysis, mech vent often needed
- g-tube nutrition
24
Q
Clostridium tetani
when must human tetanus immune globin be given by?
A
w/in 24 hrs of sx onset
25
# Clostridium tetani
prognosis
* high mortality rate with rapid onset & delayed care
* spasms for 3-4 wks
* complete recovery may take weeks
* toxin binding is irreversible, so pt must regenerate new axonal terminals
26
# Clostridium tetani
prevention
| natural infection, passive immunization, active immunization
* natural infection does not result in immunity
* passive immunization if unsure of vax status with at risk wound (give immune globin)
* active immunization for adults
27
# Clostridium tetani
Immunization schedule
| general series, boosters, pregnancy
* primary immunization: 2 doses 4-6wks apart, 3rd dose 6-12 mo later
* boosters: every 10 yrs or at time of major injury if occurs > 5 yrs after dose
* TDAP with each pregnancy (27-36 wks, but ab concentrations best for baby 27-30 wks)
28
# Clostridial myonecrosis
AKA
gas gangrene
29
# Clostridial myonecrosis
commonly due to?
trauma or IV drug use
30
# Clostridial myonecrosis
where are toxins produced? what do the toxins lead to?
1. affected tissue
2. shock, hemolysis, tissue necrosis
31
# Clostridial myonecrosis
Signs & sx
1. sudden onset
2. rapidly worsening pain
3. hypotension
4. tachycardia
5. fever
6. delirium
7. wound- swelling, pallor, foul smelling drainage
32
# Clostridial myonecrosis
Later changes to wound
1. skin turns dusky then deeply discolored
2. red fluid filling vesicles
3. gas may be palpable in tissue
33
# Clostridial myonecrosis
Dx
* x-ray
* anaerobic culture
34
# Clostridial myonecrosis
tx
* surgical debridement
* PCN, 2 mil units, Q3 hrs
* Clindamycin, 600-900mg IV, Q8 hrs
35
# C. diff
associated with?
recent abx use (as long as 8 wks prior to sx)
36
# C. diff
mode of transmission
fecal oral
37
# C. diff
MOA of infection
disrupts normal bacterial flora in bowel, colonizes the colon and releases 2 toxins
38
# C. diff
most common abx that lead to C. diff?
* fluoroquinolones
* clindamycin
* PCN
* Cephalosporins (2-4th gens)
* Carbapenems
39
# C. diff
signs & sx
* green, foul, watery diarrhea (5-15x daily)
* mucus in stool, rarely bloody
* mild LLQ tenderness
40
# C. diff
signs & sx in severe disease
| 4 sx, 4 test results
* profuse diarrhea (> 30 per day)
* fever
* hemodynamic instability from hypovolemia
* abd pain/distension
Labs
* WBC: > 30,000
* Albumin: < 2.5
* Elevated serum lactate
* Rising CR
41
# C. diff
why is albumin low with C. diff?
protein losing enteropathy
42
# C. diff
Dx
stool toxin/antigen assay available
* immunoassay for glutamate dehydrogenase (GDH) protein
* PCR for C. diff toxin gene
* Rapid enzyme immunoassy for presence of 2 C. diff toxins
* non-contrast abd CT
43
# C. diff
which test can differentiate colonization vs infection?
rapid enzyme immunoassay
44
# C. diff
what will non-contrast abdominal ct show? when to get one?
1. colonic dilation and wall thickening
2. with severe/fulminant infections
45
# C. diff
complications
| 6 things
* hemodynamic instability
* resp failure
* metabolic acidosis
* megacolon (> 7 cm)
* perforation
* death
46
# C. diff
when to consider surgical consult?
| 10 things
1. hypotension
2. fever greater than 38.5degC
3. ileus or severe abd distension
4. peritonitis or severe abd tenderness
5. mental status changes
6. WBC > 20,000
7. serum lactate levels > 2.2
8. admission to ICU
9. end organ failure
10. no improvement after 3-5 of therapy
47
# C. diff
Tx
* complex abx decision tree
48
# C. diff
prevention
* minimize abx use
* don't suppress gastric acid
* contact precautions in facilities
49
# Corynebacterium diphtheriae
AKA
diphtheria
50
# Corynebacterium diphtheriae
4 forms
1. nasal
2. laryngeal
3. pharyngeal
4. cutaneous
51
# Corynebacterium diphtheriae
mode of transmission
respiratory secretions
52
# Corynebacterium diphtheriae
exotoxin causes what 2 things?
1. myocarditis
2. neuropathy
53
# Corynebacterium diphtheriae
clinical diagnosis
consider diphtheria if relevant clinical sx and incomplete vax
54
# Corynebacterium diphtheriae
incubation period
2-5 days
55
# Corynebacterium diphtheriae
signs & sx
* sore throat
* malaise
* cervial lymphadenopathy
* low-grade fever
* early on: mild erythema/isolated spots of gray and white exudate on pharynx
56
# Corynebacterium diphtheriae
complications
* myocarditis (arrhythmia, heart block, heart failure)
* neuropathy (diplopia, slurring, dysphagia)
57
# Corynebacterium diphtheriae
dx
* clinical dx
* can confirm with pos culture
58
# Corynebacterium diphtheriae
important to detect what not what?
1. toxigenic
2. non-toxigenic strains
59
# Corynebacterium diphtheriae
tx
* administer antitoxin upon clinical suspicion
* involve PH/CDC in diagnostic/treating if strongly suspected
* erythromycin: 500mg, Q8 hrs, 14 days
60
# Corynebacterium diphtheriae
considerations for antitoxin
* have epi ready, 10% risk of hypersensitivity
* must be obtained from CDC
* dose varies based on severity
61
# Corynebacterium diphtheriae
prevention
* childhood vax series
* TDAP
* booster indicated with exposure
62
# Corynebacterium diphtheriae
prophylactic abx
Erythromycin: 500mg PO, Q8 hrs, 7 days
