Food poisoning, caused by Staphylococcus and other bacterial agents / their toxins. Botulism Flashcards
CHARACTERISTICS OF STAPHYLOCOCCUS AUREUS?
gram positive
heat stable enterotoxins - causing food poisoning
staphylococcus is destroyed by cooking however the eheat stable toxins are not
what are the clinical features of staphylococcus food poisoning ?
INCUBATION 1-8 hours
nausea
vomiting
abdominal discomfort
diarrhoea
fever uncommon
LASTS 24-48hr
DESCRIBE BACILLUS CEREUS?
gram positive rod
heat stable
spore forming (boiling does not kill the bacterium)
produce two different enterotoxins
TRANSMISSION OF BACILLUS CEREUS?
bacteria grows in heated food that cools down slowly or improperly refrigerated
such as reheated rice
what is the INCUBATION PERIOD FOR BACILLUS CEREUS?
and CLINICAL MANIFESTATION
enterotoxin 1 - emesis - acts within 30min to 1hr
enetrotixin 2 - diarrhea - acts within 6-15hrs -
waterry diarrhea , abdominal pain , typically lasting 24-48hrs
most food poisoning has a?
short incubation period
what are the CHARACTERISTICS OF CLOSTRIDIUM BOTULINUM ?
gram positive rod
spore forming! - can survive 100 degrees for several hours
obligate anaerobe !
produces HEAT LIABLE NEUROTOXIN
what are the DIFFERENT TRANSMISSION ROUTES OF BOTULISM ?
food borne botulism - ingestion of preformed botulinum toxin via contaminated food
the ANAEROBIC SPORES SURVIVE IN POORLY PASTEURISED CANNED FOOD - produce dangerous toxins
clostridium botulinum also produce gas - bulging cans
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infant botulism
ingestion of spores
present in honey , juice
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wound botulism -
germinating spores in contaminated wounds common among drug users
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iatrogenic botulism
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botulism of undetermined etiology or inhaled botulism
what is the PATHOPHYSIOLOGY OF BOTULINIUM TOXIN?
infant botulism - ingested spores germinate and produce neurotoxins within the intestinal tract
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from site of infection - the botulism toxin enters the blood stream
and reaches the neuromuscular junctions
produce proteases that cleaves SNARE proteins
preventing fusion of the transmitter vesicles with the presynaptic membranes - prevention of acetylcholine release
MOTOR FUNCTIONS ARE AFFECETD BUT NOT SENSORY!
what is the INCUBATION PERIOD OF ALL THE BOTULISMS ?
food born botulism
enterotoxins A-F
12-36 hrs
infant botulism
days to 4 weeks
wound botulism
10 days
what are the CLINICAL FEATURES OF BOTULISM?
gastrointestinal / food borne
nausea ,
vomitting ,
dry mouth
followed by constipation
absent in wound botulism
ONLY PRESENT IN 30 percent food born botulism
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infant botulism
CONSTIPATION FIRST SIGN in infant botulism
feeding difficulties
infantile hypotonia - FLOPPY BABY SYNDROME IN INANTS
increased drooling
and weak cry
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wound botulism
no prodromal gastrointestinal problem
wound itself may appear to be healing well
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all botulism can lead to
neurological symptoms
SYMETERICAL descending paralysis - begins in freq used muscles
CARDINAL FEATURES OF BOTULISM :
fever absent - EXCLUSION OF POLIOMYELITIS
symmetrical - EXCLUSION OF POLIOMYELITIS
patient remains responsive
heart rate normal or slow absence of hypotension
no sensory deficit - except blurred vision
RARE SYNDROMES:
1) ophthalmoplegia - paralysis of cranial nerves
oculomotor nerve - ptosis of eyelid - masked face
abducens nerve - diplopia
cilliary nerve - mydriasis
pupils, diploma
2) recurrence nerve - dysphonia / hoarseness of voice
3) vagus nerve - dysphagia and paralysis of pharyngeal muscles
4) trigeminal nerve - dry mouth , decreased salivation
5) impaired innervation of bladder
6) constipation or paralytic ileus
7) PARALYSIS OF INTERCOSTAL MUSCLE , DIAPHRAGM - ACUTE RESP DISTRESS SYNDROME
//rarely affects the lower extremities //
FLOPPY BABY SYNDROME IN INANTS
DIAGNOSIS OF CLOSTRIDIUM BOTULINUM ?
Cerebrospinal fluid is
normal ///////
Rapidly identify botulinum toxin in samples from serum, vomit, gastric acid, stool, or suspicious foods.
A mouse neutralization bioassay confirms botulism by isolating the botulism toxin in samples from serum, vomit, gastric acid, stool, or suspicious foods
untreated serum injected containing toxin
then serum with antitoxin A-F
ELISA test has also been developed - detect botulinum toxin
electro-chemi-luminescent (ECL)
Isolation of the organism from
food without toxin is insufficient grounds for the diagnosis
C botulinum
may be grown on selective media from samples of stool or foods
TREATMENT OF BOTULISM ?
Secure airways.
for food borne botulism
Horse-derived heptavalent botulism antitoxin (to seven of the known botulinum toxin types (A-G)
Eradication of toxin through bowel emptying (induced by medication)
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infant botulism
younger than 1 year
IV human botulism immunoglobulin globulin (BIG-IV)
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wound botulism undergo debridement (removal of wound tissue), even if the wound appears to be healing well
Anaerobic cultures should be
obtained at the time of surgery.
local instillation of antitoxin is unknown. - Penicillin G (10 to 20 million units daily). Metronidazole may be an effective alternative
Administration of horse-derived botulism antitoxin
PREVENTION OF BOTULISM ?
food borne botulism
Sterilize food through autoclaving
Food should be boiled twice before being canned to kill spores that may have germinated after the first round of boiling
separate raw and cooked, cook thoroughly, keep food at safe
temperatures, use safe water and raw materials.
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infant botulism
Avoid exposure of < 1-year-old infants to potentially contaminated material
A recommended prevention measure for infant botulism is to avoid giving honey to
infants less than 12 months of age,
as botulinum spores are often present.
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wound botulism
Avoidance of IV drug use
Seek medical attention for infected wounds.
DD OF BOTULISM?
Guillain-Barré syndrome - Ascending paralysis
Bilateral flaccid paralysis
Myasthenia gravis
poliomyelitis
Lambert-Eaton syndrome
