Food Microbiology: The Basics

What is an outbreak?

defined by the CDC as the occurrence of two or more cases of a similar illness resulting from ingestion of common food

Why is the US food supply one of the safest in the world?

because federal and state regulations and inspections, CDC traces and tracks outbreaks and foodborne illnesses, and food manufacturers and distributors are motivated to avoid lawsuits as a result of negligence

What is a foodborne illness?

an illness transmitted to humans from food and can still occur even with prevention practices

Where do 80% of foodborne illnesses occur?

in restaurants

Where do the risk of foodborne illnesses occur?

at home from canning or cross contamination

What is food biosecurity?

objective to keep food free from planned contamination with biological, chemical, or physical hazards due to malicious or criminal intent it became very big part of food supply terrorism especially after 9/11

What are the causes of foodborne illness?

Biological, chemical, physical

What are the biological causes of foodborne illness?

bacteria, molds, viruses, parasites, yeasts, prion

What are the chemical causes of foodborne illness?

plant and animal toxins, agricultural chemicals, industrial chemicals

What are physical causes of foodborne illness?

glass, bone, metal, plastic, jewelry, insects, insulation

What is important about biological causes of foodborne illness?

10x as many bacterial cells as humans cells in the human body but not all are pathogenic and they are found in every habitat on earth including our food and in/on our bodies as well as on soil, rocks, plants, oceans, and even artic snow

What does pathogenic mean?

causing or capable of causing disease

What is Salmonella?

a common bacterial food infection it comes from 75% of poultry/eggs but also handling reptiles and dairy products, actually the most common cause of illnesses traced back to foods in the US the most susceptible foods are meat fish eggs poultry and dairy products,

What is a common facultative bacterium that leads to bacterial food infections?

listeriosis monocytogenes that comes from contaminated produce, pasteurized milk, lunch meats, ready to eat meals

What is facultative bacterium?

survives with or without oxygen, can survive wide pH range, can survive COLD environments, can survive wide range of temperature (35F to 113F)

What is important about molds?

aka fungus and its a plant that lacks chlorophyll that produces a furry growth on organic matter and some are carcinogenic and some produce mycotoxins a big producer is aflatoxin - peanuts/grains, and unlike bacteria mold is visible in blooms and thrives at room temperature, need less moisture than bacteria jam jellies salty meats are susceptible

What is important about viruses?

one of nature’s simplest organisms, DNA or RNA with protein outer wall, needs a living cell in order to multiply, identified in about 3-10% of foodborne illnesses but heating over 185F (85C) kills most viruses but freezing DOES NOT

What is important about parasites?

need a host to survive, an organisms that lives on or within another organism and benefits by deriving nutrients at the host’s expense, in US fewer than 500 cases of foodborne illness two most common are roundworms and protozoa

What’s important about sushi regarding parasites?

often contain herring worms in japanese sushi and there is no commercial method to detect and candling only finds 60-70% and cooks look for them but often miss because they are very thin like thread, when consumed it causes a tingling sensation in throat from the worm wiggling, and after an hour or couple days have more symptoms in serious cases worm penetrates stomach or intestinal wall and causes abdominal pain, nausea, vomiting, diarrhea, but worms will die after several weeks or are coughed/vomited up and about 10 cases are reported every year but probably under reported you can kill them by deep freezing at -20C for 7 days and FDA regulations in place

What is important to know about prions in foodborne illness?

Mad Cow Disease is very important aka Bovine Spongiform Encephalopathy (BSE) which is a type of Transmisslbe SE (TSE) and it riddles brain with holes making it look spongy, and affects brain/neurological tissues/ causes incoordination, convulsions, death, can cause variant CJD

What is a prion?

an infectious protein particle that does not contain DNA or RNA

What are other Transmissible Spongiform Encephalopathy besides BSE?

Creutzfield Jakob (CJD) a type of dementia, Kuru aka laughing death in New Guinea from cannibalism, and Scrapie in goats or sheep

What is important about chemical hazards?

can come from plants (pesticides) and animals (fish are big one) also from chemicals used in agriculture or industry and end up in food unintentionally but also sometimes on purpose like Melamine was used in China to artificially inflate protein content in dog food but it killed several animals and lead to reform of Chinese Food Safety regulations

What are the 4 steps for food safety?

clean everything, separate, cook, chill

What is old rule of thumb for oysters and why is it wrong?

only eat oysters in months that end in R but really there is no “safe” month to eat wild oysters they can still get bacteria in cold water, but it is less likely

What is the Temperature Danger Zone?

40F to 140F (4C to 60C) but human body is 98.6F (37C) so our body is sort of a danger zone