Introduction to Human Nutrition

Food Safety 331

Campylobacter

C. jejuni

is one of the most

common causes of bacterial food poisoning in many industrialized countries. Although campylobacters are fragile organisms, and do not survive or multiply very well on foods, the low infectious dose means that a small level of contamination may result in illness. Compared with other food-borne bacteria with low infectious doses, relatively few outbreaks have been identifi ed

(a) 2–5 days(b) 1–7 days

(a) Moderate to severe

diarrhea, sometimes bloody diarrhea. Severe abdominal pain. Vomiting is rare. Complications are uncommon, but include bacteremia, reactive arthritis and Guillain–Barré syndrome

(b) 500 cells

(a) 32°C(b) 42–43°C(c) 4.9(d) 0.98

Heat-sensitive

(a) Gram

negative

(b) Fastidious

microaerophile

(a) Chickens, birds,

cattle, fl ies, and water

(b) Undercooked

chicken, raw milk, beef, pork, lamb, shellfi sh, and water

Verotoxigenic

Escherichia coli

(VTEC)

VTEC is of considerable

concern due to the severity of illness. The organism is easily killed by cooking, but the low infective dose means that foods must be cooked thoroughly and protected from cross-contamination

(a) 1–6 days(b) 4–6 days

(a) Diarrhea and severe

abdominal cramps, bloody diarrhea (hemorrhagic colitis), approx. 5% (mostly children) develop hemolytic uremic syndrome (HUS)

(b) 10–100 cells

(a) 7°C(b) 37°C(c) 4.5(d) 0.97

Heat-sensitive

(a) Gram

negative

(b) Facultative

anaerobe

(a) Cattle, sheep, pigs,

deer

(b) Undercooked beef

burgers, raw milk, salad vegetables, and unpasteurized apple juice

Listeria

monocytogenes

L. monocytogenes

causes

serious illness in individuals with impaired cell-mediated immunity. Highly susceptible individuals include pregnant women, neonates, older people and immunocompromised individuals. The organism is also reported to cause febrile gastroenteritis (FG) in healthy persons. Foods associated with transmission tend to be processed, ready-to-eat foods, with long shelf-lives (>

5 days) stored at

refrigeration temperatures

(a) Up to 10

weeks (FG: 20–27 h)

(b) Days to

weeks (FG: self-limiting, usually 1–3 days)

(a) Flu-like symptoms,

meningitis and/or septicemia. While pregnant women may experience a mild fl u-like illness, infection may result in miscarriage, stillbirth or birth of a severely ill infant. (FG: fever, watery diarrhea, nausea, headache and pains in joints and muscles)

(b) Unknown

(a) 0°C(b) 30–37°C(c) 4.3(d) 0.90

Heat-sensitive

(a) Gram positive (b) Facultative

anaerobe

(a) Soil, improperly

made silage

(b) Fresh soft cheeses,

raw milk, deli meats, pâté, hot dogs, raw vegetables, ice cream, and seafood