Bacillus Grampositive large rods Gramvariable

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Bacillus Gram-positive large rods
(Gram-variable) endospores produced aerobic to
facultative anaerobes catalase
positive polysaccharide and proteins
hydrolyzed carbohydrates fermented to acid, some
gas Species distinction based in part
on spore size, shape, location colony
morphology carbohydrates metabolized and
products formed temperature range
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Species B. larvae foulbrood in honey bees
B. thuringensis insect pathogen crystalline
body activated in gut B. cereus infant
diarrhea, no fever lower abdominal pain,
cramps present in many food products cream,
pudding, meat, dry milk, rice infant
formula
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B. anthracis anthrax rods have square ends in
chains spores ellipsoidal sporangia not
swollen noted in Genesis, 5th plague cattle
killed organism described in 1838 used by Koch
in 1876 first vaccine in 1880s mid 1800s
England woolsorters disease Germany
ragpickers disease treating fibers with
formalin reduced disease US cases 1920s 100
200/yr 1950s 20 50/yr 1970s 0
6/yr 1980s 1 /yr incidence reduced
due to vaccine for animals and high risk groups,
to improved hygiene, to decreased imports
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Agricultural and industrial disease cattle
workers, veterinarians, farm workers (bone
meal), goat hair, wool, tanning, bone
meal Anthrax forms gastrointestinal - very
rare, no cases known cutaneous handling
contaminated materials (wool, horsehair and
pig bristle brushes, goatskin drums)
inhalation - inhaling spores
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Virulence factors capsule - deters
phagocytosis toxin - 3 proteins
a.) protective antigen (PA) split by blood to
63Kd protein binds receptor on cell
surface binds other toxin components
b.) lethal factor (LF) binds PA, enters cell,
role not clear c.) edema factor (EF)
binds PA, enters cell increases cAMP in
cell alters cell activity
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Cutaneous small papule, itchy becomes
vesicle or liquid filled sac several may
coalesce vesicle ruptures revealing
depressed black area eschar lesion dries (1-2
weeks), eschar loosens, scar
remains Gastrointestinal two clinical
presentations intestinal anthrax
non-specific symptoms nausea, vomiting,
anorexia, fever progresses to abdominal pain,
bloody diarrhea, vomiting of blood may go to
shock, cyanosis and death onset of symptoms to
death 2-5 days oropharyngeal anthrax -
fever, submandibular edema, lymph node swelling
and anorexia mortality rate 25 60
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Inhalation or pulmonary anthrax benign phase
malaise, fatigue, muscle pain, mild fever,
non- productive cough resembles mild upper
respiratory tract infection acute phase
rapid onset respiratory distress with
difficulty breathing, cyanosis, respiratory
stridor, profuse sweating, elevation of pulse,
respiratory rate fever shock, pleural
effusion septicemia and meningitis may
develop death occurs within 24 hr of onset of
acute phase
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Clostridium Gram-positive large rods (Gram
Variable) motile endospores produced
anaerobic catalase negative
carbohydrates fermented to acids, alcohols and
acetone gas (CO2 , H2 and CH4 ) often
produced proteins hydrolyzed and amino acids
fermented - putrefaction habitats soil to
intestinal tract of man and animals
exotoxins and exoenzymes important factors
Species distinction spore location and
shape protein, amino acid and carbohydrate
metabolism action on milk stormy
fermentation more
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Virulence factors protease, collagenase,
elastase phospholipase cytolysin
promotes vascular injury at low concentrations
activates nutrophils which adhere to
capillary wall, causing decreased blood flow
and hypoxia activates other immune system
components, resulting in shock
enterotoxin (Toxin A in C. difficle) causes
fluid accumulation in bowel cytotoxin -
causes inflammatory response
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Botulinum toxin 7 serotypes A G A
B - botulism in humans precursor activiated in
GI tract binds neuron ends, internalized
prevents neurotransmitter release
paralysis Tetanus toxin prevents release
of inhibitory neutransmitter lockjaw
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Food poisoning C. perfingens beef, turkey,
chicken most frequent cooked in bulk, not
hot enough, kept warm too long ingest spores
(food with toxins not palatable) toxin
causes watery diarrhea, cramps C. botulinum
blood sausage botulus sausage 3 types
food borne, wound, infant food borne
improperly preserved food mild dryness of
mouth, blurred vision, double vision severe
difficulty speaking, swallowing muscle
weakness very severe difficulty breathing
wound drug abuse (needle site), nasal/sinus
(cocaine) infant ingest spores
(honey) diminished suckling, ability to
cry neck and peripheral weakness, respiratory
failure
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Tetanus in writings of Hippocrates
organism described in 1880s toxoid first
used in 1920s spores deep in tissue low
O2 incubation period 3 days to 3 weeks
generalized tetanus 80 of cases lockjaw
risus sardonicus characteristic facial
expression raised eyebrows, tight closure of
eyelids, wrinkling of forehead, extension of
corners of mouth, muscle spasms in
all muscle groups - glottis involvement death
autonomic nervous system hypotension or
hypertension tachycardia and arrhythmias
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Gas gangrene surgical procedures resulted in
massive necrosis and gangrene War of
1914-1918 renewed study 1914 12 of wounded
developed, 20 25 died 1918 incidence way
down wound contaminated with many organisms
C. welchii, C, perfringens, C. sporogenes, C.
histolyticum ferment sugars and more to
lactic acid and gas gas pressure decreases
blood flow control by tissue excision of
antibiotics C. perfringens may get to gall
bladder cholecystitis gas-filled gall bladder