Download ppt food poisoning

It is caused by the ingestion of the food contaminated by the:- 1. Living bacteria or their toxins 2.

Some times both-Multiplication and toxins production. Contaminated Meat 2. Sausages 4. Custards 5. Profuse Watery Diarrhoea Last 2 — 3 days d. Convalescent carrier state may lasting for the several weeks e. Very short hrs, 2. Short because of preformed toxins. Death is uncommon. Botulinum C and D cause toxicity in animals. Food Responsible For The Botulism: a. These are preserved home food such as b.

Home — canned vegetables c. Smoked or pickled fish d. Home made cheese e. It act on the parasympathetic nervous system. Its action on the GI — Tract is very slight. The antitoxin is of no value if the toxin is already fixed to the nervous tissues. Cook raw food thoroughly. Eat cooked food immediately 3. Prepare food for only one meal 4.

Avoid contact between raw foods and cooked foods 5. Choose foods processed for safety. Wash hands repeatedly 7. Keep all food preparation premises meticulously clean 8. Use safe water 9. Be cautious with foods purchased outside YamunaM15 Jan. Based on symptoms and duration of onset. Nausea and vomiting within six hours Staphylococcus aureus, Bacillus cereus b. Abdominal cramps and diarrhoea within hours Clostridium perfringens, Bacillus cereus c. Fever, abdominal cramps and diarrhoea within hours Salmonella, Shigella, Vibrioparahemolyticus, Enteroinvasive E.

Abdominal cramps and watery diarrhoea within hours Enterotoxigenic E. Fever and abdominal cramps within hours Yersinia enterocolitica f. Bloody diarrhoea without fever within hours Enterohemorrhagic E. Based on pathogenesis. Food intoxications resulting from the ingestion of preformed bacterial toxins. Staphylococcus aureus, Bacillus cereus, Clostridium botulinum, Clostridium perfringens. Food intoxications caused by noninvasive bacteria that secrete toxins while adhering to the intestinal wall Enterotoxigenic E.

Food intoxications that follow an intracellular invasion of the intestinal epithelial cells. Diseases caused by bacteria that enter the blood stream via the intestinal tract. The food does not ordinarily support the growth of pathogens but merely carries them.

Salmonella, Shigella, Vibrio etc. The food can serve as a culture medium for growth of pathogens to numbers that can infectthe person. Food borne infections by bacteria can also be classified as toxicosis and food-infections. In toxicosis, the toxins are released by bacteria such as Clostridia, Bacillus and Staphylococcus. In food-infections, the bacteria are ingested,which later initiate the infection.

Staphylococcus aureus:. Food is usually contaminated from infected food handler. The food handler with an active lesion or carriage can contaminate food. Incriminated food: Custard and cream filled bakery food, ham, chicken, meat, milk, fish, salads, puddings, pie etc. Incubation period: the incubation period is usually hours.

Pathogenesis: the organism may multiply in the food and produce toxin. Most food poisoning iscaused by enterotoxin A. Isolates commonly belong to phage type III. Low temperature heat inactivated enterotoxin can undergo reactivation in some food. The toxin acts on the receptors in the gut and sensory stimulus is carried to the vomiting center in the brain by vagus and sympathetic nerves. Clinical features:. The onset is sudden and is characterized by vomiting and diarrhea but no fever.

The illness lasts less than 12 hours. There are no complications and treatment is usually not necessary. The large number of S. Staphylococcal food poisoning can be diagnosed if they are isolated in large numbers from the food and their toxins demonstrated in the food or the isolated S.

Dilutions of food may be plated on Baird-Parker agar or Mannitol Salt agar. It is found abundantly in environment and vegetation. Incubation period: hours in short-incubation form and hours in long incubation form. Pathogenesis: During the slow cooling, spores germinate and vegetative bacteria multiply,then they sporulate again. Sporulation is also associated with toxin production. The toxin is heat-stable, and can easily withstand the brief high temperatures used to cook fried rice. The short-incubation form is most often associated with fried rice that has been cooked and then held at warm temperatures for several hours.

Long-incubation food poisoning is frequently associated with meat or vegetable-containing foods after cooking. The short-incubation form is caused by a preformed heat-stable enterotoxin of molecular weight less than 5, daltons. It is characterized by nausea, vomiting and abdominal cramps. In eithertype, the illness usually lasts less than 24 hours after onset.

Laboratory diagnosis:. The short-incubation or emetic form the disease is diagnosed by the isolation of B. The long-incubation or diarrheal form is diagnosed by isolation of the organism from stool and food.

Clostridium perfringens: It is a gram positive anaerobic spore bearing bacilli that is present abundantly in the environment, vegetation, sewage and animal feces. Incriminated food: food-borne outbreaks of C. Meats that have been cooked, allowed to cool slowly, and then held for some time before eatingare commonly incriminated.

Fish pastes and cold chicken too have been incriminated. Pathogenesis: Spores in food may survive cooking and then germinate when they are improperly stored. When these vegetative cells form endospores in the intestine, they release enterotoxins. The bacterium is known to produce at least 12 different toxins. Food poisoning is mainly caused by Type A strains, which produces alpha and theta toxins.

The toxins result in excessive fluid accumulation in the intestinal lumen. Incubation period: hours. Clinical features: Illness is characterized by acute abdominal pain, diarrhea, and vomiting.

Illness is selflimiting and patient recovers in hours. Laboratory diagnosis: The bacterium is present normally in the intestine, their isolation from feces may not be sufficient to implicate it. The homogenized food is diluted and plated on selective medium as well as Robertson cooked meat medium and incubated anaerobically. Incriminated food: Most cases of botulism are associated with home canned or bottled meat, vegetables and fish. In general, the low and medium acid canned foods are often incriminated.

The anaerobic environment produced by the canning process may further encourage the outgrowth of spores. Pathogenesis: Not all strains of C. Seven toxigenic types of the organism exist, each producing an immunologically distinct form of botulinum toxin. Lysogenic phages encode toxin C and D serotypes. Food-borne botulism is not an infection but an intoxication since it results from the ingestion of foods that contain the preformed clostridial toxin.

If contaminated food has been insufficiently sterilized or canned improperly, the spores may germinate and produce botulinum toxin. The toxin is released only after the death and lysis of cells.

The toxin resists digestion and is absorbed by the upper part of the GI tract and then into the blood. It then reaches the peripheral neuromuscular synapses where the toxin binds to the presynaptic stimulatory terminals and blocksthe release of the neurotransmitter acetylcholine.

This results in flaccid paralysis. Incubation period: hours Clinical features: Common features include vomiting, thirst, dryness of mouth, constipation, ocular paresis blurred-vision , difficulty in speaking, breathing and swallowing. Coma or delirium may occur in some cases.

Death may occur due to respiratory paralysis within 7 days. Spoilage of food or swelling of cans or presence of bubbles inside the can indicate clostridial growth. Food is homogenized in broth and inoculated in Robertson cooked meat medium and blood agar or egg-yolk agar, which is incubated anareobically for days at 37oC.

Some specific serotypes harbor plasmids that code for toxin production. Contamination of water with human sewage may lead to contamination of foods. Infected food handlers may also contaminate foods. The infective dose is bacilli. Pathogenesis: The bacteria colonize the GI tract by means of fimbriae to specific receptors on enterocytes of the proximal small intestine. LTs are similar to cholera toxin in structure and mode of action.

LTs are holotoxin consisting of A subunit and B subunit. The B subunit of LTs binds to specific ganglioside receptors GM1 on the epithelial cells of small intestine and facilitates the entry of A subunit where it activates adenylate cyclase. Food borne infections 7. Salmonella typhimurium Salmonella newport. Transmission 1. Consumption of contaminated food from carriers, from human excreta. Transferred to food through hands, utensils, equipments, flies etc. Presence of flies, cockroaches, rats, in the food environment that act as vectors of the disease.

Clinical features Enteropathogenic E. Enterotoxigenic E. Coli ETEC , 3. Enteroinvasive E. Enterohemorrhagic E. Diarrhea e. Vomiting b. Cramps f. Headache c. Weakness g. Chills d. Nausea Clinical Features Biotoxicants : which are found in tissues of certain plants and animals.

Eg- Mushroom toxicity. Metabolic products toxins : formed and excreted by microorganisms, while they multiply in food, or in gastrointestinal tract of man. Poisonous substances: which are present in the food during production, processing, transportation or storage. Food borne intoxications…… Food borne intoxications have short incubation periods min to hours and are characterized by lack of fever. Food borne intoxications can be classified into: a. Bacterial intoxications b.

Fungal intoxications c. Chemical intoxication d. Plant toxicants, and e. Poisonous animals. Staphylococcus aureus 2. Bacillus cereus 3.