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 some pathogens 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 renamed Paenibacillus larvae B.
popilliae milky disease of Japanese beetles
B. thuringensis insect pathogen toxin present
as crystalline body activated in alkaline gut of
insect
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Species B. cereus diarrhea with no
fever may be lower abdominal pain,
cramps spores present in many food products
rice, spices, meat, eggs, dairy
products enterotoxin 3 enterotoxins Nhe
non-hemolytic enterotoxin Hbl hemolysin
BL (also dermonecrotic) CytK cytotoxin K
(most toxic)
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Species B. cereus diarrhea lecithinase
and phospholipase also produced two hemolysins
also produced one is cereolysin
pore-forming toxin similar to
streptolysin O and pneumolysin necrosis
protein complex cause of diarrhea?
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Species B. cereus diarrhea infant formula
important source (soy) also in cream, pudding,
meat, dry milk, rice spores are significant
factor not killed by heat in fact
activated by heat! food then held at
30-50C allows growth food poisoning syndrome
two types 1. diarrhea with abdominal
cramps, no fever 8-16 hr incubation 2.
emetic disease 1-6 hr incubation period both
have 24 hr duration
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Species B. cereus diarrhea
diarrheal (long-incubation) form due to
heat-labile enterotoxin 50,000 dalton
protein activates adenylate cyclase assoc. with
meat or vegetable-containing foods organism in
50 of dried beans cereals 25 of
spices, seasoning mixes potatoes one outbreak
traced to meals-on-wheels program
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Species B. cereus diarrhea emetic
(short-incubation) form due to heat-stable
enterotoxin lt5,000 dalton protein most
often associated with fried rice Chinese
restaurants common source one outbreak due to
macaroni cheese (powdered milk) common
theme food prepared and kept at
inappropriate temperature
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Species B. cereus diarrhea 52 outbreaks
between 1972 1986 reported to CDC 2 of total
instances infant diarrhea formula contains
spores other infections with B.
cereus eye infections conjunctivitis
keratitis iridocyclitis inflammation of
iris and ciliary body dacryocystitis
infection or sac that drains tears orbital
abscess panophthalmitis purulent
inflammation of all parts of the eye
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B. anthracis anthrax rods have square ends in
chains spores ellipsoidal sporangium 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 Those at
risk cattle workers veterinarians farm
workers (bone meal in animal feeds) those who
work with goat hair and wool tanning industry
workers drum makers
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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 lecithinase membrane
damage? protease toxin - 3
proteins a.) protective antigen (PA)
split by blood to 63 Kd 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
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
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Gastrointestinal two clinical presentations
intestinal anthrax non-specific symptoms
nausea, vomiting, anorexia,
fever progresses to abdominal pain and bloody
diarrhea and 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 biphasic
pattern benign phase ? acute phase benign
phase malaise, fatigue, myalgia (muscle pain),
mild fever, non-productive cough
resembles mild upper respiratory tract infection
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Inhalation or pulmonary anthrax acute phase
rapid onset respiratory distress with dyspnea
disress in breathing cyanosis, respiratory
stridor high pitched, noisy respiration profuse
diaphoresis sweating edema of neck
chest elevation of pulse rate, respiratory rate,
temperature shock and pleural effusion
evident septicemia and meningitis may
develop death occurs within 24 hr of onset of
acute phase too much resembles other
diseases!