Introduction to Human Nutrition

Food Safety 333

Vibrio vulnifi cus

V. vulnifi cus

is considered to

be one of the most invasive and rapidly lethal of human pathogens. Infection starts with a gastrointestinal illness, and rapidly progresses to a septicemic condition. It is mostly associated with the consumption of raw oysters. Human infections are rare, but those at most risk either have underlying illnesses or are immunocompromised

(a) 16 h(b) Days to

weeks

(a) Wound infections,

gastroenteritis, primarily septicemia

(b) Unknown in healthy

individuals but in predisposed

<^100

cells

(a) 8°C(b) 37°C(c) 5(d) 0.96

Heat-sensitive

(a) Gram

negative

(b) Facultative

anaerobe

(a) Coastal waters,

sediment, plankton, shellfi sh

(b) Oysters, clams,

crabs

Yersinia

enterocolitica

Y. enterocolitica

is

psychrotrophic and known to be quite resistant to freezing, surviving in frozen food for extended periods. The organism is present in a wide range of animals, especially pigs. Milk and pork have been implicated in outbreaks, especially in countries where pork is eaten raw or undercooked

(a) 3–7 days(b) 1–3 weeks

(a) Diarrhea, abdominal

pain and fever. Intestinal pain, especially in young adults, may be confused with appendicitis

(b) Unknown

(a) –1.3°C(b) 25–37°C(c) 4.1(d) 0.96

Heat-sensitive

(a) Gram

negative

(b) Facultative

anaerobe

(a) Wide range of

animals (e.g., pigs, dogs, cats) and water

(b) Undercooked pork,

raw milk and water

a Under otherwise optimal conditions; limits will vary according to strain, temperature, type of acid (in the case of pH), solut

e (in the case of A

) and other factors.w

b Not an exhaustive list.Heat-sensitive: cells destroyed by typical cooking temperatures; Min.: minimum; Opt.: optimal; A

: water activity.w