Staphylococcus aureus in food

Staphylococcus aureus is one of the most successful human pathogens, with global distribution and the potential to cause, potentially fatal disease.

Staphylococcus aureus may be present in virtually any food because it can reproduce within wide ranges of temperature, acidity and salt content.

The organism is well-arm with potent virulence factors, survival fitness, and antimicrobial resistance determinants. The largest numbers tend to be found near openings to the body surface such as the anterior nares, axillae and the inguinal and perineal areas. It has tremendous capacity to cause harm when an opportunity such as wound or weakened immune system presents itself.

In addition, Staphylococcus aureus produces a wide range of virulence factors – proteins that help the bacteria sustain an infection and damage human host cells.

The main sources of staphylococcal contamination are food handlers and contamination typically occurs after heat treatment of the food. The two most important causes to foods are nasal carriers and individuals whose hands and arms are inflicted with boils and carbuncles, who are permitted to handle foods.

Commonly identified sources of Staphylococcus aureus foodborne illness include red meats and sausages; cheeses; cream-filled pastries; milk; dairy product; and salads made with chicken, mayonnaise, pasta with tomato sauce, egg, tuna and macaroni.

Staphylococcus aureus can be transferred from the mouth to food via the spoon. If the spoon is left for some time at a warm temperature the bacteria will grow, multiply and produce toxin.
Staphylococcus aureus in food

Food-borne pathogenic bacteria: Vibrio cholerae

Vibrio cholerae belonging to O1 and O139 sero-groups cause cholera, a life threatening diarrheal disease that spreads through consumption of water and food contaminated with the pathogen. Vibrio cholerae O1 is the causative agent of cholera.

Although Vibrio cholerae is a human pathogen, the bacteria are part of the normal aquatic flora in estuarine and brackish waters and thus are able to persist in the environment outside human host.

Cholera was originally endemic in eastern India. Up to 1960, it had extended from India in six pandemics over the world.

Vibrio cholerae is a motile rod with a single polar, sheathed flagellum. It can grow in peptone water with 6% NaCl.

Although cholera is considered a waterborne disease, there is an evidence indicates the importance of food, particularly seafood, in the transmission of cholera.

The physicochemical characteristics of foods that support survival and growth of Vibrio cholerae O1 are high moisture content, neutral or alkaline pH, low temperature, high organic content and an absence of other competing bacteria.

Pathogenic vibrios are capable of producing three clinical manifestations of infection: gastroenteritis, soft tissue infections and systemic infections in including bacteremia.
Food-borne pathogenic bacteria: Vibrio cholerae

Autoimmune disorders foodborne infection

Consumers are often unaware that there are long-term as well as short term consequences of foodborne microbial disease.

Several foodborne bacteria including staphylococcus, streptococcus, Yersinia and clostridium have superantigens.

Many of these are thought to be associates with several autoimmune disorders such as rheumatic heart disease, rheumatoid arthritis, multiple sclerosis, Grave disease and Crohn disease.

What are autoimmune disorders? Autoimmune disorders are disease caused by the body producing an inappropriate immune response against its own tissue.

Normally, the immune system should be able to distinguish between ‘self’ and ‘not self’ and only attacks those tissues that it recognizes as ‘not self’.

Graves disease is an autoimmune thyroid disease mediated by autoantibodies to the thyrotropin receptor. The disease may be inked to an infection with Y. enterocolitica serotype 0:3.

Campylobacter jejuni leads to a serious autoimmune disorder that affects peripheral nervous system resulting in flaccid paralysis called Guillain-Barre syndrome.
Autoimmune disorders foodborne infection

Effect on economy productivities by foodborne disease

Foodborne disease has been identified by World Health Organization as – any disease of an infectious or toxic nature caused by, or thought to be caused by, the consumption of food or water.

Foodborne disease continues to be one of the largest public health problems worldwide, and is also an important cause of reduced economic productivities.

For example, economic loss from trichinosis, toxoplasmosis, salmonellosis, campylobacteriosis and beef tapeworm in the USA in 1985 was estimated to be over US$1.5 billion.

The reasons are:
*The group of people who have increased susceptibility to foodborne illness is increasing, such as children under 5 years of age, the elderly, the immunocompromised and the malnourished.

*Changing of lifestyle which resulted changes of eating habit: More people eat out, more people rely on processed foods for fast meal, increased mass production of food, and tourism sector so that people are exposed food borne hazard from other place.

Increasing consumption of fresh fruits and vegetables in a number of countries, dining in restaurants and salad bars which relatively rare 50 years ago, they today a major source of food consumption. As a result an increasing number of outbreaks are associated with food prepared outside the home.

*Another aspect the increase in urban populations and decline rural communities. This development has caused fundamental changes in food consumption patterns, food processing, and even food hazards.

*Emerging pathogens – frequent outbreaks caused by new pathogens or the use of antibiotics.
*New technologies and processing methods – other chemicals hazards, such as naturally occurring toxicants, may arise at various points during food production, harvest, processing and preparations.
Effect on economy productivities by foodborne disease

Foodborne Illness

Foodborne Illness
Foodborne illness may follow ingestion of foods contaminated with bacteria, algae, protozoa, parasites and other organism, as the result of food sensitives or chemical or drug contamination.

Foodborne illness is an important cause of acute morbidity and increased short term mortality.

Approximately 600 outbreaks of foodborne illness are reported to the CDC every year.

In addition, infections with Salmonella, Campylobacter and Yersinia enterocolitica are associated with increased long term mortality.

When faced with the symptoms of acute gastrointestinal illness, structural, functional and metabolic causes must also be considered.

Because incubation periods of foodborne illness may quite long, with many meals and other activities occurring in the interim, the association between contaminated food intake may not be made or may be erroneous.

Evaluating the differential diagnosis and initiating treatment before a definitive diagnosis is available are significant clinical challenges.

Bacterial organisms are the most common cause of foodborne illness and may be result of other direct action of the organism or the action of endo or exotoxins.

The incubation period depends on whether there is a preformed exotoxin, which generally produces symptoms sooner than illness that results from organisms that must first reproduce and elaborate a toxin in the gastrointestinal tract.

Salmonella was the most commonly reported foodborne poisoning reported to the CDC. Other common bacterial causes included Escherichia coli, Clostridium perfringes, Shigella, Staphylococcus aureus, Bacillus cereus, Complybactor species, Streptococcus, listeria monocytogenes, Clostridium botulinum, Vibrio parahaemolyticus and Y. enterolitica.

Marine agents and toxins may produce similar symptoms. Common parasitic causes of diarrhea include Guardia, Cryptosporidium and Entamoeba histolytica.

Rotavirus is the most common cause of acute diarrhea among children, accounting for one fourth of all cases, but many virus can cause diarrhea as well, including Norwalk like virus, enteric adeno-viruses, astroviruses and calciviruses.
Foodborne Illness

Foodborne Disease Definition

Foodborne Disease Definition
A foodborne disease is considered to be any illness associated with or in which the causative agent is obtained by the ingestion of food.

Approximately 66% of all foodborne illness outbreaks are caused by bacterial pathogens.

Of the 200 foodborne outbreaks reported each year, approximately 66% are of undetermined etiology.

Unidentified causes may be from the Salmonella and Campylobacter species, Staphylococcus aureus, Clostridium perfringes, Clostridium botulinum, Listeria monocytogenes, Escherichia coli 0157, Shigella, Vibrio and Yersinia enterolitica, which are transmitted through foods.

A wide variety of home cooked and commercially prepared foods have been implicated in outbreaks, but they are most frequently related to foods of animals origin, such as poultry, eggs, red meat, seafood and dairy products.
Foodborne Disease Definition

Bacteria in General

Bacteria in General
Bacteria are single celled organisms that can cause foodborne illness in two ways

1. They can infect foods themselves, by their presence in the food as they feed on it
2. They can produced toxins, which can make food hazardous, as they breakdown. Bacteria, under good condition, can grow and divide quickly – each cell dividing into two approximately every 20 minutes.
   

Good conditions for bacterial growth require

• Food – especially high protein

• Acidity – neutral to low acid

• Temperatures –especially 40 – 140 degree F, ideal temperature is 90 to 100 degree F about body temperature

• Oxygen

• Moisture

When one or more of these six factor is present in a food product, creating the conditions for bacterial growth, that food product is a potentially hazardous food. Potential hazardous foods therefore include meats; poultry; fish; soy-based foods; eggs; milk and milk products; cooked pasta, rice, potatoes, or beans; garlic oil mixture; raw fruits and vegetables; and raw seeds and sprouts. Some of these items surprise many people – it’s not the mayonnaise that is the problem on a buffet; rather, it is the moisture content and low acidity of the items that are put into mayonnaise – potatoes, pasta, beans, etc. Some bacteria even produce spores that don’t reproduce but can survive heating and cooling so that as conditions improve the spore’s bacteria can become active again.
Bacteria in General

Shigella as a Pathogen

Shigella as a Pathogen
Shigellosis, or bacillary dysentery, as it is commonly known, is caused by bacteria of the genus Shigella (S. dysenteriae, S. flexneri, S. boydii and S. sonnei). The normal habitat for Shigellae is the intestinal tract of humans and other primates. They are rarely found in other animals. The main source of Shigellae involved in outbreaks is asymptomatic carriers or persons recovering from disease. Shigellae may persist in the intestinal tract for month.

Symptoms of shigellosis, after an incubation period of 1-7 days (usually less than 4 days), include diarrhea, abdominal pain, fever, and vomiting. The severity of the disease may vary from very mild to severe diarrhea with bloody stools, mucus secretion, and dehydration. Generally foodborne shigellosis is characterized by a high attack rate common source epidemiology, and short incubation periods of 7 – 36 hours. Symptoms usually persist for 3 – 14 days. Frequently, an asymptomatic carrier state may develop during convalescence, lasting from a few days to several months. Human volunteer studies indicate that ingestion of as few as 1 – 100 organisms can induce illness.

The disease is caused by invasion of the intestinal mucosa. An enterotoxin, classically referred to a Shiga toxin, may be produced by S. dysenteriae and possibly by S. flexneri.
Shigella as a Pathogen