360 ◾ Fundamental Food Microbiology
(Figure 26.5). Persons with no visible symptoms can shed the cells in feces for a long time. The
main symptoms are enteric and include abdominal cramps, profuse diarrhea, nausea, and vomiting. Other symptoms include fever, headache, and chills. In some cases, bloody diarrhea has been
reported. An individual can have a relapse of symptoms after a short interval.
Consequence of campylobacteriosis in humans result in a chronic disease called Guillain-Barre
syndrome, a debilitating generalized paralysis. Chronic infection promotes antibody production
against Campylobacter antigen, which reacts with nerve cells causing impaired nerve function.
Another consequence of campylobacteriosis is arthritis, also known as Reiter’s syndrome.
Food Association
Because the organism is present in high frequency in animals, birds, and the environment, many
foods, both from plant and animal sources, can be contaminated with Cam. jejuni. The foods
can be contaminated directly with fecal material from animals and infected humans or indirectly
from sewage and contaminated water. Cam. jejuni has been isolated at a very high frequency from
raw meats (beef, lamb, pork, chicken, and turkey), milk, eggs, vegetables, mushrooms, and clams.
In heat-processed food, their presence has been related to cross-contamination following heat
treatment or to improper heating. The use of animal feces as fertilizers was found to contaminate
vegetables. Outbreaks of campylobacteriosis result from the consumption of raw milk, improperly cooked chicken, dairy products, bakery products, turkey products, Chinese food, eggs, and
others. Consumption of raw milk and chicken were implicated in many outbreaks. Although
the organism is a poor competitor against other microorganisms present in a food and generally
does not grow well in foods, enough cells can survive in a contaminated food to provide the dose
required for the disease.
Prevention
It is rather difficult to control the access of Cam. jejuni to raw foods, particularly foods of animal
origin. However, proper sanitation can be used to reduce its load in raw foods during production, processing, and future handling. Preventing consumption of raw foods of animal origin,
heat-treatment of a food when possible, and preventing post-heat contamination are important to
control campylobacteriosis in foods of animal origin. Contamination of vegetables can be controlled by not using animal feces as fertilizer and not using contaminated water to wash vegetables
(especially ready-to-eat types). Contamination from humans can be reduced by establishing good
personal hygiene and not allowing sick individuals to handle foods, especially ready-to-eat foods.
Yersinia enterocolitica 34
Importance
The genus Yersinia now includes 17 species, and only three species are pathogenic to humans:
Yersinia enterocolitica, Yer. pseudotuberculosis, and Yer. pestis. The most important aspects about
the organism and the disease are that Yer. enterocolitica is a psychrotroph and can grow at 0°C,
and its symptoms include a sharp abdominal pain with fever, mimicking appendicitis. Yer. pseudotuberculosis is quite common in animals (pigs, cats, dogs, beavers) and birds and has been isolated
in foods, and its involvement in foodborne illnesses is confirmed. Yer. pestis is also a pathogenic
(Figure 26.5). Persons with no visible symptoms can shed the cells in feces for a long time. The
main symptoms are enteric and include abdominal cramps, profuse diarrhea, nausea, and vomiting. Other symptoms include fever, headache, and chills. In some cases, bloody diarrhea has been
reported. An individual can have a relapse of symptoms after a short interval.
Consequence of campylobacteriosis in humans result in a chronic disease called Guillain-Barre
syndrome, a debilitating generalized paralysis. Chronic infection promotes antibody production
against Campylobacter antigen, which reacts with nerve cells causing impaired nerve function.
Another consequence of campylobacteriosis is arthritis, also known as Reiter’s syndrome.
Food Association
Because the organism is present in high frequency in animals, birds, and the environment, many
foods, both from plant and animal sources, can be contaminated with Cam. jejuni. The foods
can be contaminated directly with fecal material from animals and infected humans or indirectly
from sewage and contaminated water. Cam. jejuni has been isolated at a very high frequency from
raw meats (beef, lamb, pork, chicken, and turkey), milk, eggs, vegetables, mushrooms, and clams.
In heat-processed food, their presence has been related to cross-contamination following heat
treatment or to improper heating. The use of animal feces as fertilizers was found to contaminate
vegetables. Outbreaks of campylobacteriosis result from the consumption of raw milk, improperly cooked chicken, dairy products, bakery products, turkey products, Chinese food, eggs, and
others. Consumption of raw milk and chicken were implicated in many outbreaks. Although
the organism is a poor competitor against other microorganisms present in a food and generally
does not grow well in foods, enough cells can survive in a contaminated food to provide the dose
required for the disease.
Prevention
It is rather difficult to control the access of Cam. jejuni to raw foods, particularly foods of animal
origin. However, proper sanitation can be used to reduce its load in raw foods during production, processing, and future handling. Preventing consumption of raw foods of animal origin,
heat-treatment of a food when possible, and preventing post-heat contamination are important to
control campylobacteriosis in foods of animal origin. Contamination of vegetables can be controlled by not using animal feces as fertilizer and not using contaminated water to wash vegetables
(especially ready-to-eat types). Contamination from humans can be reduced by establishing good
personal hygiene and not allowing sick individuals to handle foods, especially ready-to-eat foods.
Yersinia enterocolitica 34
Importance
The genus Yersinia now includes 17 species, and only three species are pathogenic to humans:
Yersinia enterocolitica, Yer. pseudotuberculosis, and Yer. pestis. The most important aspects about
the organism and the disease are that Yer. enterocolitica is a psychrotroph and can grow at 0°C,
and its symptoms include a sharp abdominal pain with fever, mimicking appendicitis. Yer. pseudotuberculosis is quite common in animals (pigs, cats, dogs, beavers) and birds and has been isolated
in foods, and its involvement in foodborne illnesses is confirmed. Yer. pestis is also a pathogenic