[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fNm2LgREcfHUwxBkj5L9TheAkSWnxm_I1HvZgJV_9pKE":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":101},[4,8,12,16,20,24,28],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"type":33,"data":34},"blog",{"slug":35,"title":36,"description":36,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":39,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"body":43,"faq":44,"tags":45,"related":47},"foodborne-illness-food-poisoning-and-causative-agents-of-foodborne-illness","Food Poisoning: Definition, Causative Agents",null,"Acharya Tankeshwar","2013-02-23","2026-07-05",false,"bacteriology","Foodborne illness, also known as “foodborne disease,” “foodborne infection,” or “food poisoning, is an important public health burden worldwide. There are an estimated 250 pathogens that can cause foodborne-related illnesses. Centre for Disease Control (CDC), USA, has reported 31 known foodborne illness agents; the rest are called “unspecified agents.”\n\nFoodborne illness is two or more cases of similar illnesses resulting from ingesting a common food. It can result from consuming foods contaminated with various pathogens. Usually, bacteria are the primary pathogen, followed by viruses, then parasites. However, organisms’ natural or manufactured chemicals and toxins can also cause foodborne illnesses.\n\nWhen the performed toxins are responsible for good poisoning, symptoms appear within 1 to 6 hours of ingestion. Symptoms of food poisoning include stomach upset, abdominal cramps, nausea and vomiting, diarrhea, fever, and dehydration. Symptoms may range from mild illness to severe disease.\n\n![Food Poisoning (foodborne illness) - Food Poisoning](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FFood-posoning-279x300.jpg)Figure: Food Poisoning\n\n## Foodborne Intoxications vs. Foodborne Infections\n\nThe ingestion of toxins causes foodborne intoxications, natural or preformed, bacterial or chemical, and the incubation period ranges from minutes to hours.  *Bacillus Cereus, Clostridium botulinum*, *Staphylococcus aureus* are the common causes of foodborne intoxication.\n\nMnemonicsOrganismsSourceE atingE . coli O157-H7undercooked meat, esp. hamburgersC ontaminatedC lostridium botulinumImproperly canned vegetables and smoked fishS tuffS almonella spppoultry, meat, eggsC ausesC lostridium perfringensreheated meatV eryV ibrio parahaemolyticusseafoodB ig\u002F B adB acillus cereusreheated riceS mellyS taphylococcus aureusmeats, mayo, custardV omitV ibrio vulnificusSeafood\n\nLive bacteria, viruses, or parasites are responsible for foodborne infections. They invade and multiply in the lining of the intestine and the incubation period varies from hours to days. *Campylobacter jejuni, Listeria monocytogenes, and Escherichia coli*0157:H7 are the major causes of foodborne infections.\n\n*MNEMONICS: “Eating Contaminated Stuff Causes Very Big Smelly Vomit”*\n\n## Common pathogens causing food-borne illness are\n\n### Bacillus cereus\n\nIngestion of food contaminated with *Bacillus cereus* or toxins produced by this organism is responsible for foodborne illness. The spore of *Bacillus cereus* is relatively heat resistant and survives the steaming and rapid frying of rice. The spores germinate when rice is kept warm for many hours (e.g., reheated fried rice).\n\n*Bacillus cereus*produces enterotoxins. It causes food poisoning of two types: **diarrheal type, characterized by a long incubation period (18 hours), abdominal pain and watery diarrhea**, and **emetic type, with a short incubation period of 4 hours, and manifested as profuse vomiting.** Emetic type resembles staphylococcal food poisoning, whereas diarrheal type resembles clostridial gastroenteritis.\n\n### Campylobacter jejuni\n\n*Campylobacter jejuni* is the **world’s most common bacterial cause of human gastroenteritis**. People acquire this infection after consuming food and water contaminated with animal feces. As this organism is commonly found in domestic animals such as cattle and chickens, **consuming unpasteurized milk or raw or improperly poultry or meat predisposes this infection.** Dogs are also the reservoir of *Campylobacter,* so contact or playing with puppies with diarrhea is a common source of infection for children.\n\nProper cooking and following food hygiene while preparing food help to prevent *Campylobacter* infections. Proper cooking of food kills \\*Campylobacter,\\*so it is the best method of eliminating campylobacter from contaminated foods.\n\n### Clostridium perfringens\n\n*Clostridium perfringens*, the etiological agents of gas gangrene (myonecrosis), also causes food poisoning if people acquire this organism via ingestion.  Spores of this organism are found abundantly in soil and are extremely heat resistant, which can even survive cooking.\n\nConsumption of improperly cooked food especially heated meat dishes, predispose to food poisoning. Certain strains of *Clostridium perfringens* produce an enterotoxin that causes watery diarrhea. This enterotoxin acts as a superantigen similar to the enterotoxin of *S. aureus.*\n\n### Clostridium botulinum\n\nExotoxin produced by *Clostridium botulinum* in the **contaminated canned food** causes botulism. Clostridium botulinum spores are widespread in soil and can contaminate meat and vegetables.\n\nThe highest risk foods are smoked fish and alkaline vegetables such as green beans, peppers, and mushrooms. Spores survive and germinate in the anaerobic environment when these foods are canned or vacuum-packed without adequate sterilization. *Clostridium botulinum* produces toxins in this canned food, and people may inadvertently ingest toxins while consuming such foods.\n\nSimple precautions such as inspection of canned foods can prevent you from eating contaminated foods. **Do not buy or use swollen cans.** Swollen cans result from proteolytic degradation of foods by\\*Clostridium,\\*which causes gas formation. Proper sterilization of all canned and vacuum-packed foods and sufficient cooking of foods can prevent food poisoning caused by *Clostridium botulinum.* The **botulinum toxin** is relatively heat-labile and is inactivated by boiling for several minutes.\n\n### E.coli O157:H7\n\n[Enterohemorrhagic E. coliO157: H7](\u002Fenterohemorrhagic-escherichia-coli-ehec-infections\u002F) cause food-borne outbreaks associated with eating undercooked meat, especially hamburgers, in fast-food restaurants.\n\nCattle are the main reservoir of *E. coli* O157:H7 strain. **Bacteria in cattle feces are ingested in undercooked hamburgers.** *E. coli*O157:H7 strain produces an exotoxin called Shiga toxin and causes bloody diarrhea. It can cause hemorrhagic colitis and hemolytic uremic syndrome (HUS).\n\n### Listeria monocytogenes\n\n*Listeria monocytogenes*causes **listeriosis,** a food-borne illness that can have severe consequences for children, the elderly, and pregnant women. Outbreaks of listeria infections are associated with eating unpasteurized cheese and delicatessen meats and are the major cause of concern for food industries. Contaminated dairy products, undercooked meats such as chicken, and hot dogs can also cause, cause outbreaks.\n\n### Salmonella Typhimurium and S. Enteritidis\n\n*Salmonella* is one of the US’s most common causes of **bacterial enterocolitis**. Nontyphoidal species of *Salmonella* are mainly responsible for causing diarrhea, while typhoidal species (*S. typhi* and*S. paratyphi*) cause enteric fever.\n\nPeople acquire this infection by ingesting food and water contaminated with the feces of humans and animals. The most frequent source of infection is **poultry and eggs.** Inadequately cooked meat products such as hot dogs and improper handling of foods by **chronic carriers** also cause significant outbreaks.\n\n### Shigellaspp\n\nShigellosis is also known as bacillary dysentery. Most cases are caused by *Shigella sonnei.* However, *S. dysenteriae*, *S. flexneri,* and *S. boydii*can also cause foodborne illnesses.\n\n### Staphylococcus aureus\n\n*Staphylococcus aureus* is one of the leading causes of food poisoning or foodborne illness, characterized by prominent vomiting and watery diarrhea. **Heat-resistant preformed enterotoxin of S. aureus** in food is responsible for food poisoning, and symptoms usually appea**r within 1 to 6 hours** after ingesting contaminated foods.\n\nThis enterotoxin is resistant to stomach acid and enzymes in the stomach and jejunum. There are six immunologic types of enterotoxin, **types A-F**. Enterotoxin of *S. aureus*acts as a [superantigen](\u002Fsuperantigen-examples-roles\u002F) within the gastrointestinal tract.\n\n### Vibrio cholerae\n\nThe cholera toxin produced by *Vibrio cholerae* is an enterotoxin responsible for profuse watery diarrhea (rice watery stools).\n\n### Yersinia enterocolitica\n\n*Yersinia enterocolitica*causes enterocolitis. People acquire infection with this organism by consuming food or water contaminated with excreta of domestic animals such as cattle, dogs, and cats.\n\n### Parasites\n\n1. *Toxoplasma gondii:* Toxoplasmosis is caused by an intracellular protozoan, *Toxoplasma gondii*, which can infect all species of mammals, including humans\n2. *Cryptosporidium*\n3. *Cyclospora*\n\n### Virus\n\n1. Adenovirus\n2. Rotavirus\n3. Calciviruses (Better known as Norwalk virus)\n4. Norwalk-like virus (or Norovirus)",[],[46],"food-microbiology",[48,56,63,71,77,83,89,95],{"slug":49,"title":50,"description":50,"seoTitle":37,"seoDescription":37,"author":51,"createdDate":52,"lastUpdatedDate":40,"draft":41,"category":53,"image":37,"faq":54,"tags":55},"food-preservation-method-canning","Canning: Types, Procedure, and Applications","Samikshya Acharya","2023-05-22","general-microbiology",[],[46],{"slug":57,"title":58,"description":58,"seoTitle":37,"seoDescription":37,"author":59,"createdDate":60,"lastUpdatedDate":40,"draft":41,"category":53,"image":37,"faq":61,"tags":62},"food-spoilage-causes-and-prevention","Food Spoilage: Causes and Prevention","Alisha Tripathi","2023-03-15",[],[46],{"slug":64,"title":65,"description":65,"seoTitle":37,"seoDescription":37,"author":66,"createdDate":67,"lastUpdatedDate":40,"draft":41,"category":53,"image":37,"faq":68,"tags":69},"pasteurization-food-preservation-method","Pasteurization: Types and Advantages","Aastha Shrestha","2023-03-01",[],[70,46],"sterilization-disinfection",{"slug":72,"title":73,"description":73,"seoTitle":37,"seoDescription":37,"author":66,"createdDate":74,"lastUpdatedDate":40,"draft":41,"category":53,"image":37,"faq":75,"tags":76},"lactic-acid-fermentation","Lactic Acid Fermentation","2023-02-19",[],[46],{"slug":78,"title":79,"description":79,"seoTitle":37,"seoDescription":37,"author":66,"createdDate":80,"lastUpdatedDate":40,"draft":41,"category":53,"image":37,"faq":81,"tags":82},"microorganisms-found-in-food","Microorganisms Found in Food","2023-02-17",[],[46],{"slug":84,"title":85,"description":85,"seoTitle":37,"seoDescription":37,"author":66,"createdDate":86,"lastUpdatedDate":40,"draft":41,"category":53,"image":37,"faq":87,"tags":88},"food-preservation-methods","Food Preservation: Methods and Their Importance","2023-02-08",[],[46],{"slug":90,"title":91,"description":91,"seoTitle":37,"seoDescription":37,"author":66,"createdDate":92,"lastUpdatedDate":40,"draft":41,"category":53,"image":37,"faq":93,"tags":94},"fermented-foods-types-examples-and-health-benefits","Fermented Foods: Types, Examples, and Health Benefits","2022-12-19",[],[46],{"slug":96,"title":97,"description":97,"seoTitle":37,"seoDescription":37,"author":66,"createdDate":98,"lastUpdatedDate":40,"draft":41,"category":53,"image":37,"faq":99,"tags":100},"prebiotics-mechanisms-sources-and-examples","Prebiotics: Mechanisms, Sources, and Examples","2022-12-04",[],[46],[102,108,115,120,123,126,130,135,139,143],{"slug":103,"name":38,"description":104,"image":105,"body":106,"postCount":107},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",433,{"slug":109,"name":110,"description":111,"image":112,"body":113,"postCount":114},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",81,{"slug":116,"name":117,"description":118,"image":37,"body":37,"postCount":119},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":121,"name":51,"description":118,"image":37,"body":37,"postCount":122},"samikshya-acharya",20,{"slug":124,"name":59,"description":118,"image":37,"body":37,"postCount":125},"alisha-tripathi",6,{"slug":127,"name":66,"description":128,"image":37,"body":37,"postCount":129},"aastha-shrestha"," Author \u002F Contributor",9,{"slug":131,"name":132,"description":133,"image":37,"body":37,"postCount":134},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":136,"name":137,"description":118,"image":37,"body":37,"postCount":138},"srijana-khanal","Srijana Khanal",18,{"slug":140,"name":141,"description":133,"image":37,"body":37,"postCount":142},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":144,"name":145,"description":118,"image":37,"body":146,"postCount":147},"nisha-rijal","Nisha Rijal","**Nisha Rijal** is a microbiologist and quality assurance specialist. She served for nearly 12 years as a microbiologist at the National Public Health Laboratory (NPHL), Nepal's national reference laboratory, and continues to work as a consultant microbiologist in international public health organization. ",51]