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Food/Industrial Microbiology: Food Microbiology & Foodborne Illness
 Most food illness is caused by bacteria (94
...
3%), and third is
everything else (1
...
20 billion dollars to US economy
- 48 million illnesses, 128 thousand hospital visits and 3,000 deaths just in the US; this number
could be very off though, with between 25:1 – 100:1 cases actually being reported
...

Some Facts:
- 1/5 of all illness linked to leafy greens
- 1/2 of all illness linked to produce
- 1/5 of death from poultry
*-most frequent sources in Europe and N
...
milk, poultry, milk, eggs)
- outbreaks usually occur from some sort of mass distribution of contaminated food (eg
...
They share information in real time
...
They
linked this to a single restaurant’s barmaid
...
Linked several cases to one plant making
approx
...


Gastrointestinal Tract
Mouth
-mechanical breakdown of food
- saliva is alkaline, contains amylase and antimicrobial factors
-diverse microflora
- Plaque contains Fusobacterium & Streptococcus
Stomach
- food is mixed with acidic gastric juice
- Kills most ingested microbes ( except spores or acid tolerant vegetative cells)
- Vitamin B12 is absorbed
Small Intestine
- Duodenum; chime is mixed with digestive juice from the pancreas and bile from gall bladder
- Jejunum/ Ileum; Amino acids, sugars, fats, vitamins, minerals, and water are absorbed into capillaries
in the villi
- Home to large (400 species, 1014) population of bacteria; population increases as further down small
intestine you get
Colon
- active absorption of water and salts
-large microbial population; obligate anaerobes are present
Normal gut microflora protect against infection
- occupies available niches
-production of organic acids and bacteriocins
- stimulation of host immune system
ONLY 1/10 CELLS IN THE BODY IS HUMAN
Diarrhea: excessive evacuation of too-fluid feces
Virulence Factors
-acquired via horizontal gene transfer
- encoded on pathogenicity islands
- ability to evade host defense mechanisms
Exotoxin Production
-Enterotoxins: act on intestinal mucosa
- Cytotoxins: kill host cells
- Neurotoxins: interfere with nervous transmission
Endotoxins
-released by bacterial lysis
- Pyrogenic: fever producing

Major Types of Bacterial Food Poisoning
Intoxication
- ingestion of a pre-formed toxin
- eg
...
Salmonella, Enterohemmorhagic E
...
coli (EPEC)
Toxicoinfection
-viable bacteria ingested with food and colonize the intestinal lumen
-occurs primarily in the small intestine
-attach to specific receptors on epithelial surface via adhesins
- produce protein enterotoxins
-eg
...
coli



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