Foodborne Illness II
In the gastrointestinal tract there are 3 centers (Musocal-associated Lymphoid Tissue
Lamina propria: B, T, and null cells, macrophages (engulf pathogens)
B and T cells, macrophages, M cells
Lymph nodes: areas where the Lymph, along with many cells and particles it
carries (notably lymphocytes, macrophages, and foreign antigens) drains out of
tissues and seeps across the thin walls of tiny lymphatic vessels. The vessels
transport the mix to lymph nodes, where antigens can be filtered out and
presented to immune cells.
When the host defense system is impaired, risk increases:
At risk populations
Antacids increase the stomachs pH and allows foodborne pathogens to
pass through the stomach
Consumption of a large volume of liquids reduces the time that organisms
are in the stomach, therefore increasing their chances of survival
Consumption of fatty foods: the fat protects the pathogens
Chronic maladies associated with diarrhea:
Arthritis, kidney damage, heart disease, and neurological damage
Arthritis associated with Campylobacter, Salmonella, Shigella, or Yersinia
2% of exposures trigger arthritis (100-200,000 cases of reactive arthritis
from foodborne illness a year)
Associated with the HLA-B27 antigen (histocompatibility antigen), 20%
of these individuals develop arthritis
Gullain-Barre Syndrom (a neurological condition) where gastrointestinal
illness precedes GBS in 10-30% of cases. The result of GBS is paralysis
and sometimes death.
Pathogenic Escherichia coli:
Lives in the GI tract of most mammals, many are not harmful
Gram negative organism, motile (peritrichous flagella), rods that belong to the
Member of the coliform group which by definition ferment lactose to acid and
gas, E coli is
a member of the fecal coliform group that can produce acid and gas
at higher temperatures than other bacteria.
About 30% of serotypes cause disease in humans or animals
Types of pathogenic E coli:
Enteroaggregative: causes prolonged diarrhea (up to 14 days) with bloody
stool when the tips and sides of intestinal villi are blunted or destroyed.
Enterohemorrhagic (EHEC) (E coli 0157H7): the most common type of e
coli in the U.S. Cattle is the known presumed reservoir. It causes
abdominal cramps with bloody diarrhea, no fever or leukocytes in stool.
Infection can lead to renal failure after a prodrome of gastroenteritis. It is
non-invasive and produces Shiga-like toxins, also called verotoxins.