2. Aerobic Gram-positive spore forming bacilli:
Bacillus anthracis and other Bacillus species
Bacillus anthracis
Aerobic , Gram positive, Spore forming bacilli
Causes anthracis, a zoonotic disease transmitted from animals to
humans
Definition of Cases in anthracis diagnostics
Confirmed Case:
Clinically compatible confirmed by isolation of B. anthracis
based on two laboratory tests
Suspected Case:
Clinically compatible with one supportive lab test
3. Three forms of anthracis disease
Cutaneous anthracis
Usually forms black necrotic ulcer (eschar)
Inhalational anthracis
Hypoxia and dyspnea, often with radiographic evidence of mediastinal
widening. Most serious
Gastrointestinal anthracis
Abdominal distress, usually accompanied by bloody vomiting and diarrhea,
followed by fever, septicemia (poorly cooked meat.
4. Cutaneous anthracis
Vesicle development Day 2
Day 4
Day2 Day 6
Day 10
Mediastinal Widening and Pleural Eschar formations
Effusion on Chest X-Ray in Inhalational
Anthrax
5. B. anthracis:
Presumptive Identification
specimen (blood, CSF, etc.)
Gram Positive Isolate on SBA
Capsule production
Madusa Head Colony
NonHemolytic
NonMotile
Spores Gram stain
Malachite green
6. B. anthracis:
Confirmatory Identification
Isolate
Capsule DFA
Phage
lysis Capsule antigen
Horse Bicarbonate
Cell wall
blood media
(M’Fadyean (M’Fadyean stain
Stain) India ink stain)
7. Recommended Post-exposure Prophylaxis to
Prevent Inhalational Anthrax
Initial Therapy Duration
Adults Ciprofloxacin 60 days
500 mg PO BID
OR
Doxycycline
100 mg PO BID
Children Ciprofloxacin* 60 days
10–15 mg/kg PO Q 12 hrs Change to
OR amoxicillin
Doxycycline: if susceptible
>8 yrs and >45 kg: 100 mg PO BID
>8 yrs and <45 kg: 2.2 mg/kg PO BID
<8 yrs: 2.2 mg/kg PO BID
*Ciprofloxacin not to exceed 1 gram daily in children
Patient information sheets at www.bt.cdc.gov
8. Cutaneous Anthrax Treatment Protocol
Category Initial Therapy (Oral) Duration
Adults Ciprofloxacin 60 daysw
500 mg BID
OR
Doxycycline
100 mg BID
Children Ciprofloxacin** 60 daysw
10–15 mg/kg Q 12 hrs
OR
Doxycycline:
>8 yrs and >45 kg: 100 mg BID
>8 yrs and <45 kg: 2.2 mg/kg BID
<8 yrs: 2.2 mg/kg BID
**Ciprofloxacin not to exceed 1 gram daily in children. w60-day duration is to prevent inhalational anthrax.
Patient information sheets at www.bt.cdc.gov
*Source MMWR 2001;50:909–19
9. Inhalational Anthrax Treatment Protocol*
Category Initial therapy (intravenous) Duration
Children Ciprofloxacin Switch to oral
10–15 mg/kg Q 12 hrs therapy when
OR clinically
Doxycycline appropriate:
>8 yrs and >45 kg: Ciprofloxacin
100 mg Q 12 hrs 10–15 mg/kg Q 12 hrs
>8 yrs and <45 kg: OR
2.2 mg/kg Q 12 hrs Doxycycline
<8 yrs: >8 yrs and >45 kg:
2.2 mg/kg Q 12 hrs 100 mg BID
AND >8 yrs and <45 kg:
One or two additional 2.2 mg/kg BID
antimicrobials <8 yrs: 2.2 mg/kg BID
**Ciprofloxacin not to exceed 1 gram daily wContinue for 60 days (IV and po combined)
Patient information sheets at www.bt.cdc.gov
*Source MMWR 2001;50:909–19
10. Immune Protection Against Anthrax
Live cellular vaccines
"Sterne" type live spore
Former USSR STI live spore
"Pasteur" type
Sterile, acellular vaccines
US "anthrax vaccine adsorbed" (AVA)—not licensed
for use in civilian populations
UK "anthrax vaccine precipitated" (AVP)
11. Other Bacillus species: B. cereus, B. subtlis
Large, motile, saprophytic bacillus with Heat resistant spores
Lab diagnosis – Demonstation of large number of bacilli in food
Food poisoning (meat, poultry, and soups)
Diarrheal syndrome (Heat labile enterotoxin)
Emetic form (Pre formed heat and acid stable toxin) ( with fried rice)
Bacillus subtilis
Common laboratory contaminant
12. Anaerobic Gram-positive spore forming bacilli:
1. Closteridium perfringens: Gas gangrene and Food Poisoning
Gram-positive, anaerobic, nonmotile, capsulated, spore-forming
rods
Clostridium (Greek Kloster meaning spindle)
Spores if formed are oval, sub-terminal and non bulging
Causes Gasgangrene: How?
Saccharolytics strongly ferment carbohydroates and produce acid and gas
Proteolytic digests proteins, blackening soul smell due to sulfur
compounds, in addition to toxins
food poisoning: How? (enterotoxin heat labile toxin produced in colon, -toxin
responsible for necrotizing enterocolitis)
toxin
Lyses of RBCs, platelets, leucocytes and endothelial cells that increased
vascular permeability leading to Hepatic toxicity and myocardial
dysfunction
14. Diagnostics: Litmus Milk Reaction showing
Saccharolytic and proteolytic properties of Cl. perfringnes
1- Acidic Reaction
Fermented to Litmus Indicator
Lactose Acid Pink Color
in Milk
2- Basic Reaction
Digestion Litmus Indicator
Casein Alkaline amines Blue Color
in Milk
2- Stormy fermentation
Too much acid and gas
15. Anaerobic Media
Thioglycollate broth
Sodium thioglycollate (Reducing agent, obsorbs O2)
Rezazurin (redox indicator, can be added)
Soft-liquid Agar
Robertson's Cooked Meat Medium
Meat particles of heart muscles contain
hematin & glutathione reducing agent
Anaerobic Jar
Plastic jar with a tightly fitted lid. Hydrogen is
introduced from commercially available hydrogen generator
envelop.
10 ml of water is added to envelop immediately before placing
it in the jar. Hydrogen and carbon dioxide will release and react
with oxygen in the presence of catalyst to form water droplet
16. Treatment of illness
No specific treatment. Supportive care include:
Restore intravenous fluid, monitor urine, and control fever and pain
Consider hyperbaric oxygen therapy. Why?
Clostridia lack superoxide dismutase, making them incapable of surviving in the
oxygen-rich environment created within a hyperbaric chamber. This inhibits
clostridial growth
Antibiotics as high doses of penicillin, Clindamycin may help
The hallmarks of this disease are rapid onset of myonecrosis with
muscle swelling, severe pain, gas production, and sepsis, so
controlling these is priority
17. Clostridium tetani: Tetanus (meaning Contract in Greek)
Gram-positive, anaerobic, motile, drum-stick spore-
forming rod commonly found: Soil, GI tracts of animals,
environments.
Therefore, spores enter through animal bites, accidental
cuts, punctures, wounds, burns, umbilical stumps,
frostbite, and crushed body parts.
Common disease symptoms:
Tetanospasmin – Heat labile neurotoxin blocks release of
neurotransmitter (glycine)for muscular contraction; muscles
contract uncontrollably. Tetanolysin, heat stable hemolysin
Death most often due to paralysis of respiratory muscles
Estimated human lethal dose(2.5 ng/kg).
Diagnosis is mostly by physical, medical, clinical symptoms
and immunization history
18. Types of Tenaus
Generalized Tetanus: spreads to muscles of the face, neck and truck in usually a
descending pattern.
local tetanus: toxin reaches motor nerve endings, neurones of the peripheral
nerve to the anterior horn cells, and cause local tetanus
Ascending tetanus: toxins spreads upwards
Neonatal tetanus: …generalized baby spasm.
Usually if the mother has not been immunized
.
Cephalic Tetanus: Rare; from otitis media
19.
20. Diagnosis, Prophylaxis, and treatment options
Diagnosis: Gram stain
Spore are diagnostic, bigger than bacteria, and bulge as drum-stick
Diagnosis is mostly by physical, medical, clinical symptoms and immunization
history
Prophylaxis, and treatment options
Antitoxin therapy with human tetanus immune globulin; inactivates circulating
toxin
Control infection with penicillin or tetracycline; and muscle relaxants
Supportive therapy (ventilator)
Vaccine available; booster needed every 10 years
Part of regular vaccination schedule:
Triple Vaccine DPT (Diphtheria, Pertussis, Tetanus)
Nowadays: DTaP-Polio-Hib
23. Clostridium Botulism : Case Presentation
An afebrile and alert patient reported at a local hospital with
blurred and double vision, muscle weakness, drooping eyelids,
slurred speech, and apparent difficulty swallowing was.
Immediate treatment was suggested including:
Antitoxin administration
Supportive Care
mechanical ventilation
body positioning
Induced vomiting
24. Clostridium botulism (Botulus = sausage in Latin)
Gram positive, anaerobic, Mobile, subterminal spore forming
bacilli
Three botulism Types:
Foodborne botulism
(incubation period ) 6 hours-8 days ( Preformed toxin ingested from contaminated
food) home canned Food, honey, crushed wounds, drug injection
Infant botulism, foods such as honey
Wound botulism (incubation period) > 4 days
25. Mechanism of Botulism toxin
Produce seven botulism toxins A –G
One of the exteremely potent toxins known 1 aerosolized gram
could potentially kill 1 million people
Prevents release of neurotransmitter acetylecholine
Toxin enters blood stream and binds to cholinergic nerves blocks
release of acetylcholine and prevents muscle contractions
resulting in descending paralysis starting with cranial nerves to
downward to respiratory obstruction
Toxin destroyed by boiling, but spores need higher temp
26. Botulism Laboratory Procedures
Microscopic/culture not reliable, toxin detection and assay
Toxin neutralization in mouse
serum, stool, gastric aspirate, suspect foods
Isolation of C. botulinum
in food/faeces, wound, tissue, or gastric
Strict anaerobe, extremely sensitive to oxygen
Clinical signs
Electromyography also diagnostic
27. Prophylaxis and Treatment
Immediate Intensive care once suspected clinically…
Ventilator for respiratory failure
trivalent antitoxin, administer gastric lavage,
metronidazole or penicillin eliminates veg form from GI,
Botulinum antitoxin
Derived from equine source
Trivalent and bivalent antitoxins available through the CDC
Licensed trivalent antitoxin neutralizes type A, B, and E and
botulism toxins
Botulism immune globulin
Infant cases of types A and G
28. Therapeutic uses of Botulism Toxin
Involuntary muscles, such as uncontroled eye movements
Cosmetic use
Caution required:
70 yrs old underwent
botulinum toxin injection
to the left inferior rectus muscle,
Resulted in loss of the muscle
29. Clostridium difficile-Associated Diarrhea
(CDAD)
A group of long term facility patients who were under
extended antibiotic treatment all suddenly developed
watery diarrhea 10 to 15 times a day, dehydration, fever, loss
of appetite, nausea, and abdominal pain/tenderness, and
signs of pseudomembranous colitis (damaged
tissues,mucus in feces). Upon a quick Gram staining, gram
positive spore forming bacilli dominated in samples from
all patients.
Reason: Antibiotic overuse
Long term treatment with broad-spectrum antibiotics kills
the other bacteria, allowing C. difficile to overgrow, produce
enterotoxins that damage intestines, cause diarrhea and
colitis
30. Clostridium difficile
Gram positive, anaerobic spore forming, bacilli
Normal resident of colon
In the industrialized world, it is one of the most common
diarrheal infections in hospitals and long-term care facilities
Causes antibiotic-associated colitis
relatively non-invasive; treatment with broad-spectrum antibiotics kills
the other bacteria, allowing C. difficile to overgrow
Produces enterotoxins that damage intestines
Major cause of diarrhea in hospitals
Increasingly more common in community acquired diarrhea
31. Treatment and prevention
Mild uncomplicated cases respond to fluid and
electrolyte replacement and withdrawal of
antimicrobials.
Severe infections treated with oral vancomycin or
metronidazole and replacement cultures
Increased precautions to prevent spread
