One that prepares and sells drugs and other medicines; a pharmacist
Name some EARLY Food Safety Laws or Controls
Hebrews and Eqyptians governed meat handling
Greeks and Romans prohibit watering down wine and short measuring grains and oils
Merchants and apothecary guilds (Internal / self-regulated guilds and merchants) in the Middle Ages prevented adulteration of spices and drugs which were extremely valuable; as proven by the spice wars in the 1700s
Discuss what brought about the evolution of food safety laws
Coincided with the industrial revolution
People lost control of their food supply (had to trust others)
People moved from agricultural production areas to urban areas
Food must now be transported, stored, preserved, processed, and packaged
The use of toxic chemicals increases
Thus, by the 1900s more regulation is needed
Consider: Food from all over the world sitting “fresh” at Wal-Mart at any given time. People have to trust big business that food is safe.
Discuss major problems of the 1900s
Industrial revolution and profits dramatically increase problems
Toxic colors and preservatives
“Patent” quack medicines (MRS. Winslow’s Soothing syrup contains opium for teething babies)
Medicines often contained opium, morphine, heroin, and cocaine without restrictions
Medicines often worthless…ie, colored water as treatment for scurvy.
What does BOC stand for? What did it later become?
Bureau of Chemistry; USDA
The BOC later became the FDA
What did Harvey Washington Wiley (year?) do?
Harvey Washington Wiley (1883) – Chief Bureau of Chemistry (later FDA); USDA
Demonstrated the power of investigative journalism
Expanded BOC staff and capability
Exposed many various problem products with drugs and food
Backed by popular journals (no tv or internet; journals and mags were huge) such as Collier’s Weekly, Ladies Home Journal, Good Housekeeping
Journals exposed “Saw dust in bread, coal char in meat, chalk as fillers”
Discuss the actions of the Early Bureau of Chemistry (BOC) -- What years?
Thr Early Bureau of Chemistry (BOC) set up “Poison Squads” in 1902-1904 which was a needed grass roots effort to get legislative changes
They took all meals to the BOC and found that meals contained additives of concern. The BOC also tested body fluids and looked for clinical toxicity (early toxicology)
Describe a situation in which Buyer Beware is fine versis a situation in which Buyer Beware is not fine. When is regulation required?
Be sure to consider both sides (biz and consumer) of this issue. Buyer Beware works in some cases (buying a t-shirt) but is unfair in other situations (food). And how much regulation is really required? Do we need to test the farm for everything and protect it from everything? Prescriptions are hard to prescribe in some cases (need a doc for heart meds) but easy in others (ex-lax).
Discuss “The Jungle” by Upton Sinclair – Year?
Described practices in Chicago meat packing plants
One million copies sold in first year
Turned down four times for publication
Copy given to President Roosevelt and the president was outraged
“Old sausage” dosed with Borax and glycerine and dumped into the hoppers
“There would be meat stored in great piles in rooms; and the water from leaky roofs would drip over it, and thousands of rats would race about on it. It was too dark in these storage places to see well, but a man could run his hand over these piles of meat and sweep off handfuls of the dried dung of rats. These rats were nuisances, and the packers would put poisoned bread out for them; they would die, and then rats, bread, and meat would go into the hoppers together”
Discuss some early pioneers that brought about change in Food Safety Laws
The General Federation of Women’s Clubs (esp. Alice Lakey and the Women’s Temperance Union)
Articles of Samuel Collins Adams in Collier’s magizine on patent meds and advertising fraud. These articles highlighted the widespread adulteration of ethical drugs and foods.
Harvey Washington Wiley (BOC) helped write the Collier’s Articles, expanded staff and capability of the BOC, exposed problems with food and drugs...
Poison Squads of the BOC tested food and performed clinical toxicology
The Jungle of Upton Sinclair in 1906 revealed horendous conditions in meat packing plants
President Roosevelt reads The Jungle and becomes outraged.
What was the name of the first comprehensive federal food law?
Pure Food & Drug Act of 1906 aka The Wiley Act
Discuss the Food & Drug Act of 1906 (The Wiley Act)
1st Comprehensive Federal Food Law
Wiley Act, stands as the most consequential regulatory statute in the history of the US
Has had the longest lasting and most widespread economic, political, and institutional impact (OMG we intervened in big business!)
Gave unprecedented new regulatory powers to the federal government
Empowered a bureau that evolved into today’s FDA
Considerable opposition from industry
Pure Food & Drug Act of 1906 was the most daunting intrusion by federal authorities into interstate commerce….
Make a decision and then look for information to support the decision as opposed to Science in which one looks at all of the information and then makes a decision.
Prions are an infectious protein particle: an infectious particle of protein that, unlike a virus, contains no nucleic acid, does not trigger an immune response, and is not destroyed by extreme heat or cold. These particles are considered responsible for such diseases as scrapie, bovine spongiform encephalopathy (Mad Cow), kuru, and Creutzfeldt-Jakob disease.
Prions cause mad cow disease because cows do not normally eat each other however "calf feed" still contains blood of slaughtered cows. Sure there have not been any US Cases of mad cow because of this fact but think; you have never been in a fatal car accident yet you still wear your seat belt.
Is it good to recommend fruits and vegetables as a nutritionist?
Hmmm, remember, nutrition does not matter if the food is not safe? How about the listeria outbreak that resulted in catelope killing several people? E. coli in bean sprouts/spinach etc...
Review the happenings around 1906?
Around 1906 government does not want to interfere with the money of big business (industrial revolution includes food) but the consumer outcry was far too great to ignore and the Grass Roots efforts prevailed. As such, the Federal Food & Drug Act of 1906 was born.
Describe the Federal Meat Inspection Act (year?)
The Federal Meat Inspection Act 1906-1907
Mandatory inspection of livestock before slaughter
Postmortem inspection of every carcass
Sanitary standards established for slaughterhouses and processing plants
Authorized USDA to conduct ongoing monitoring and inspection
List some concerns/problems with the Pure Food & Drug Act of 1906
Burden of Proof was on the FDA/BOC…
Many legal cases highlighted the strengths and weaknesses in law
Food adulteration was still common
Limited food purity standards (i.e. food colors, water, grass seed, pectin, fruit jam)
Limited analytical techniques (how to determine contaminants? Chemistry slow)
Weak on food & drug safety… (standards for meat packing existed via the Meat Inspection Act of 1906-1907 but still weak)
What led to a revision of the Food & Drug Act of 1906? When did this revision occur? What was it called?
Though there were several failed attempts to revise the act due to strenuous industry objection… the 100 deaths from the “Elixir of Sulfanilamid” and other incidents led to a revision of the Food & Drug Act of 1906 with the 1938 Food, Drug & Cosmetic Act
Describe the 1938 Food, Drug & Cosmetic Act and which act did it replace?
The 1938 Food, Drug & Cosmetic Act replaced the Pure Food and Drug Act of 1906
Goods had to be safe (not necessarily effective until 1938) so now “Snake Oils” are limited because now goods must be “Safe and Effective”
Included cosmetics and therapeutic devices
Pre-market safety testing of drugs
Toxic substances prohibited in foods unless “unavoidable” or “required in processing”
Authority for factory inspections
Proof of fraud no longer required to stop false claims (previously only the maker had to “believe efficacy")
Safety tolerances were authorized for pesticide residues (appropriateness still questionable)
Standards were developed for many foods
What big event occured about 30 years after the Pure Food & Drug Act of 1906?
Elixir of Sulfanilamid in 1937- Raspberry Flavored Death
100 deaths from the Elixir of Sulfanilamid
A letter by Dr. A.S. Calhoun, October 22, 1937 expresses the seriousness of prescribing medicine that is tainted...
"But to realize that six human beings, all of them my patients, one of them my best friend, are dead because they took medicine that I prescribed for them innocently, and to realize that that medicine which I had used for years in such cases suddenly had become a deadly poison in its newest and most modern form, as recommended by a great and reputable pharmaceutical firm in Tennessee: well, that realization has given me such days and nights of mental and spiritual agony as I did not believe a human being could undergo and survive. I have known hours when death for me would be a welcome relief from this agony." (Letter by Dr. A.S. Calhoun, October 22, 1937)
List some problems with the 1938 Food, Drug & Cosmetic Act
Burden of proof still on FDA
- WWII created extra work:
- New drugs, chemicals, and new processing
- In 1949 special committee formed to address the numerous cancer cases - The Chemical in Food Committee
Discuss the Chemical in Food Committee (year?)
The Chemical in Food Committee was formed in 1949
to investigate 'chemicals in food' as a result of the 'cancer outbreak' in the United States
The Chemical in Food Committee of 1949 shifted the burden of proof of safety to industry which helped to relieved an unmanageable situation for the FDA
The Chemical in Food Committee was chaired by James T. Delaney
- The Chemical in Food Committe of 1949 brought forth 3 Major Amendments to the 1938 Food, Drug & Cosmetic Act
- * Miller Pesticide Amendment (1954)
- * Food Additive Amendment (1958)
- * Color Additive Amendments (1960)
Remember we had learned to can food and use tin cans. There was no global food supply so to can and spray/use chemicals etc to keep food safe and stored was important. However, we paid a price in post WWII due to the health effects of chemical use.
Discuss the Miller Pesticide Amendment (include what year? and what law it amended?)
1954 amendment to the 1938 Food, Drug & Cosmetic Act
Establishment of tolerances for pesticides on raw food, commodities, and some processed foods
Pre-market safety and efficacy testing allows for risk vs. benefit evaluation
FDA enforced tolerances
Discuss the Food Additives and Color Additives Amendments (include years and what law they amended)
- Food Additives Amendment - 1958
- Color Additives Amendment - 1960
- Both amended the 1938 Food, Drug & Cosmetic Act
- Major change in FDA approach to safety of additives
- - Mandatory pre-market testing for safety
- - Shifted burden of proof of safety to industry
Emphasized safety under specific conditions of use
Developed Generally Recognized As Safe (GRAS) Substances
Covered: sweeteners, preservatives, animal drug residues, cumulative pesticides, packaging/processing chemicals, and colors. Intentional and non-intentional additives.
If it is in a capsule it is not a food name a law and year that deals with the issue of supplements...
The 1994 Dietary Supplement Health & Education Act
What clause of what law declared a war on cancer? Discuss the clause.
The Delaney Clause (1958) amended the 1938 Food, Drug & Cosmetic Act as part of the war on cancer
Focused on carcinogens
No chemical can be added to food or animal feed that has been shown to be a carcinogen by appropriate tests (animal studies)
Zero Tolerance for Zero Risk
Created a dilemma for cumulative and non-cumulative pesticides
Focused on Additives but carcinogens are in peanut butter etc
What about “really trace” amounts in the environment etc…
Technology can also now detect more and more even DDT in breast milk
Based only on the risk of carcinogenicity and the benefits of the pesticide may not have been considered
Applied to pesticides in processed foods, but focused on residues of cancer causing pesticides as it increased during processing (i.e. ketchup vs. raw tomatoes)
Discuss the (year?) Cranberry Incident
The 1959 Cranberry Incident is when aminotriazole residues were detected in cranberry products (Delaney Clause)
Recall of cranberry products during Thanksgiving !
“Said Secretary Flemming at a press conference specially called just 17 days before Thanksgiving: two batches of the cranberry crop from Washington and Oregon had been found contaminated from improper use of a toxic weed killer called aminotriazole. The chemical, he said, had been tested on rats and had caused thyroid cancer. And so consumers should avoid buying Washington and Oregon cranberries until a way is found to separate the good berries from the bad. In fact, said Flemming, housewives should be "on the safe side" and not buy any, unless they could be sure that the berries were not tainted. As his advice hit the headlines, housewives, supermarkets and restaurants swept cranberries off their shelves, shopping lists and menus.” --TIME Magazine Nov. 23, 1959
Parts per billion
Discuss Rachaeal Carson's "Silent Spring" in 1962
Publication of Rachaeal Carson’s “Silent Spring” in 1962
Rachel Carson, a respected marine biologist
An expose of the damage to the environment from indiscriminate use of pesticides especially chlorinated pesticides like DDT
“Levels of DDT at an all time high” … “over increasingly large areas of the United States spring now comes unheralded by the return of birds, and the early mornings are strangely silent where they once where”
The Impact of “Silent Spring”
A plea for less harmful methods of pest control and a changed attitude toward nature
We must abandon the idea of “conquering” nature and seek instead to work with its processes (the movement)
Book quickly became a best-seller
Chemical and pesticide industry alarmed by book’s success and attack it
Presidential Scientific Advisory Committee Study
Unreasonable fear of residues? Safety first?
Bald eagle soft eggs because of DDT
A technology that seems harmless may have serious long-term effects on the environment
Actions of humans have become the dominant environmental influence on the health and well-being of the planet
Birth of environmental movement in America can be traced to the publication of Silent Spring
- In 1992 picked as the most influential book in the
- last 50 years
We now had discussions to make… “How Green Should We Be??
From the 1960s until the mid-1990s, the Delaney clause combined with the growing cancer-phobia created problems for regulating chemical residues in food.
~~ Maybe now in 1990s with excellent chemistry and technology we need to relook at Delaney Clause.
Discuss problems with the Delaney Clause of 1958
Zero risk legislation - No Residues: However, analytical detection of chemicals increased markedly, ppb or lower
How to interpret it??
One-hit, on-molecule theory of cancer (will one sunburn give us skin cancer?)
No concept of cancer threshold
There are pesticides not food additives on raw products
Pesticides become food additives if they concentrate in processed foods.
What Act abolished the Delaney Clause?
The Food Quality Protection Act of 1996
Discuss the Food Quality Protection Act of (year?)
The Food Quality Protection Act of 1996
Negligible risk (1 in a million) for carcinogens “de minimus”
No residues in edible portion (decided by government committee)
10x safety factor for children
What are your thoughts on this? Can we enforce it? What about our global food supply and the global food supply? Cancer rates seem to be dropping (but what about hormonal levels etc?)
What is the most recent food safety law? Discuss it.
Food Safety Modernization Act (Dec 2010/Jan 2011)
Enables FDA to focus on preventing food safety problems rather than relying primarily on reacting to problems
Provides FDA with new enforcement authorities designed to achieve higher rates of compliance with prevention and risk-based food safety standards and to better respond to and contain problems when they do occur.
Gives FDA important new tools to hold imported foods to the same standards as domestic foods.
Directs the FDA to build an integrated national food safety system in partnership with state and local authorities
Substance that is analyzed: the substance being identified and measured in a chemical analysis
Bacteria (size, number of cells?)
Single-celled, ~3 microns in size
(about 1/10th size of eukaryotic cells)
Bacteria are Prokaryotic. Describe Prokaryotic Bacteria.
No nucleus or mitochondria
Usually no membrane-bound organelles
Unicellular? Yes, BUT it can form an aggregate matrix called a biofilm
- difficult to disrupt
- attach to surfaces
Quorum sensing is the ability of bacteria to communicate and coordinate behaviour via signaling molecules
Describe some common morphology in bacteria.
- Most Common
- Spherical: cocci, coccus
- Rod-shaped: bacilli, bacillus
- Some rods are:
- comma shaped (vibrio)
- spiral-shaped (spirilla)
- coiled (spirochetes)
Cell Walls of Bacteria - Contrast Gram Negative and Gram Positive.
Made of peptidoglycan ( N-acetylglucosamine & N-acetylmuramic acid…to 3-5 D-amino acids)
Two main categories are important for bacteria classification. Both are based on its reaction to stain…
Gram Positive: thicker peptidoglycan layers & teichoic acids (polysaccharides of glycerol phosphate or ribitol phosphate)
Gram Negative: thin peptidoglycan surrounded by lipid membrane containing & lipoproteins unique lipopolysaccharides
A Gram positive bacterium has a thick layer of peptidoglycan. A Gram negative bacterium has a thin peptidoglycan layer and an outer membrane
Some Gram-positive bacteria can form endospores which are highly resistant, dormant structures
NO gram-negative bacteria can form endospores.
Endospores can survive extremes in: heat, pH, chemicals, freezing, dehydration, irradiation, pressure, age…
Certain genera such as Bacillus, Clostridium are problems in food safety and human health…botulism (C. botulinum), anthrax (B. anthracis), tetanus (C. tetani), gangrene (C. perfringens), C-Diff (C. difficile)
Aerobes need oxygen to survive….
Facultative anaerobes can grow without oxygen but can utilize oxygen if it is present
Obligate anaerobes live and grow in the absence of oxygen
Antonie van Leeuwenhoek
- Most bacteria need a light microscope to be seen
- First observed by Antonie van Leeuwenhoek in 1676
- Used a single-lens microscope of his own design.
- Called them “animalcules“
- Considered Father of Microbiology
Name some people/dates that laid the foundation for microbiology & food microbiology
The name Bacterium was introduced by Christian Gottfried Ehrenberg in 1828
In 1859 Louis Pasteur demonstrated that the fermentation process was caused by the growth of microorganisms
About the same time (late 1800’s, Robert Koch, Joseph Lister, John Snow and others contributed to the “Germ Theory” of disease - Nobel Prize was awarded for this in 1905
Laid foundation for microbiology & food microbiology
Standard Aerobic Plate Count
Used to determine the presence, types, and number of microorganisms in food
Step 1: Portion of food samples blended or homogenized (stomacher)
Step 2: Serially diluted in appropriate diluent (often phosphate buffer, Butterfields) - Goal is to get it diluted enough to be countable
- Step 3: Plated in agar or selective media
- * Spread Plate Method: Spread OVER
- * Pour Plate Method: Mixed In
Step 4: Incubated at appropriate temp and time
Step 5: Visible colonies or cells are counted (reported in Colony-Forming Units, CFU’s)
What are CFUs
Save labor and time by reducing microbial testing to three simple steps:
- 1. Inoculate
- 2. Incubate
- 3. Count
The plates already have Agar (nutrient rich and specific) on them along with graph lines to simplify counting.
What is MAP?
Modified Atmosphere Packaging
What is APC?
Aerobic Plate Count
What is another term for describing a method of using only sterile procedures in a lab?
What is a gas pack system?
A system that uses chemicals to remove oxygen
A method for obtaining countable plates. Dilute... then dilute the dilution..then dilute the diluted dilution so on and so forth until the bacteria are diluted enough to be countable.
What is a Quebec Colony Counter?
A lighted gridded box that makes counting bacteria colonies easier.
What is the point of APC?
Aerobic Plate Count (APC) or Total or Standard Plate Count indicates level of aerobic microorganisms in a product in CFU/gram
No selective of differential media is used
Both “Good” and “Bad” organisms
can sometimes be used to indicate quality, spoilage, handling, or over-all sanitation of product.
can test foods at several different points in processing
look for potential sources of contamination
Are high numbers always bad? No... just noteworthy
Coliform Bacteria (shape? illness? gram pos or neg? found where?)
Coliform Bacteria are a rod-shaped “indicator” of sanitary quality (indicator of the presence of poo)
Gram-negative, non-spore forming, can ferment lactose with production of acid & gas when incubated at 35-37°C.
Found in the aquatic environment, soil, vegetation, feces of warm-blooded animals
Not normally cause of illness, they are easily cultured & presence is indicator that other pathogenic organisms are present (bacteria, viruses, protozoa, parasites of fecal origin)
- Typical genera include:
More specific: fecal coliform: Escherichia (the E in E. coli!)
Discuss E. Coli (full name, shape, how found, indicitive of, etc)
- Escherichia coli (E. coli)
- rod-shaped coliform
- distinguished from other coliforms by ability to ferment lactose at 44°C in the fecal coliform test, and by growth & color reaction on specific culture media (ie..an EMB, Eosin Methylene Blue plate)
A positive result for E. coli is metallic green colonies on a dark purple plate.
E. coli are almost exclusively of fecal origin & their presence is confirmation of fecal contamination
However, some strains are not just indicator organisms. some E. coli can cause serious illness
Fecal Coliform (gram neg or pos? shape? oxygen? spores?...)
Fecal coliform: facultative anaerobe, rod-shaped, gram-negative, non-sporulating, capable of growth in presence of bile salts, oxidase negative, produce acid & gas from lactose within 48 hours at 44 ± 0.5°C
What are Enterobacteriaceae and what are they indicitive of?
Enterobacteriaceae are a large family of gram-negative, facultative anaerobic bacteria.
They include many pathogens such as Salmonella, Escherichia coli, Yersinia pestis, Klebsiella & Shigella
Immunoassays can screen food samples for specific bacterial, viral (or chemical or physical) antigens or antibodies (analytes). In other words, not the bacteria or pathogen itself but indicators of its existence. For example the existence of dead bacteria in cooked food.
An antibody, or immunoglobulin, is a large Y-shaped protein produced by white blood cell lymphocytes (B-cells) that is used to identify & neutralize foreign objects such as bacteria & viruses
The antibody recognizes a unique part of the foreign target, called an antigen
Immunoassays rely on the antibody to bind with the antigen (usually in microtiter plates or wells) and then react with radioactive tags, enzymes, metals…
Then a measurement of color change, radioactivity…etc is used to determine the presence of the analyte
Usually looks for color...
Antibodies recognize what?
Explain the ELISA Technique
Enzyme-linked immunosorbent assay (ELISA)
Used to test for pathogenic bacteria (antigens), HIV, food allergens, aflotoxin
- Very sensitive test
- Small sample needed
Polymerase chain reaction (PCR) is a technique used to amplify a piece of DNA
generates millions of copies of a DNA sequence
can be used to identify small amounts of bacterial DNA in food products
Sample will be repeatedly heated & cooled in a thermocycler to separate DNA into single strands
During cooling, DNA primers attach to sample and a heat stable polymerase attaches nucleotides to replicate the DNA…making more strands….and the process keeps repeating until millions of copies (amplicons) of the DNA are made
For bacterial identification, a known DNA segment of a pathogen is compared to the sample.
Artificially made nucleic acid fragment: a nucleic acid fragment that is the product of the artificial large-scale reproduction of genetic material
What are some good questions to ask as new methods are developed
- Does the sample need pre-enrichment?
- How sensitive is the method?
- How accurate is the method?
- Is the method approved?
What are some organizations that approve testing methods?
- International Standards Organization (ISO)
- AOAC International
- FDA Bacteriological Manual
Why would we use the PCR method?
Looking for tiny bits of a certain bacteria's DNA is much faster than trying to grow the bacteria.
- Sterilization equipment
- A strong steel vessel that can be pressurized (high heat steamer)
How do you write the name of a bacterium?
Species in Italicized, Capitalize first letter only. If hand written, underline the entire name.
Salmonella ssp. (gram neg/pos? shape? spore forming? motile? oxygen?)
- Non-spore forming (but tough! - Can be killed w/ heat)
- Usually motile (2 phases - can spread)
- Facultative anaerobe (w/ or w/o oxygen)
- ZERO Tolerance (in lab use aseptic techniques)
- Not limited to raw or cooked food
- Now common in poultry industry (even in eggs no more raw egg ingredients)
Long history of causing food borne illness
- First identified in 1885 by USDA researchers
- Dr. Daniel Salmon & Theobald Smith
Large outbreaks associated with: salad, raw milk, cheese, pasteurized milk, ice cream, cooked and raw eggs, mayonnaise, spices, sprouts, OJ, meat, cereals, peanut butter, tomatoes, chocolate, meats
- Group of bacteria:
- a group of bacteria that share a characteristic set of antigens
More about Salmonella ssp.
Produce hydrogen sulfide…which allows them to be detected in media containing ferrous sulfate (TSI) Triple Sugar Iron agar
- Two recognized species S. enterica and S. bongori
- Many strains, or serovars (serological variants ~ 2500)
Zoonotic infections: GI tract of animals, humans
- Sources of infection:
- infected food, usually with unusual color, odor, chewiness
- Poor kitchen hygiene, especially problematic in institutional kitchens….can lead to large outbreaks
What is TSI
(TSI) Triple Sugar Iron agar (Samonella media)
Define Zoonotic Infections
Coming from animals
Name two recognized species of Salmonella
Many strains, or serovars (serological variants ~ 2500)
Chemoorganotrophic means it can survive or thrive on a variety of organic substances...
Salmonella ssp. is chemoorganotrophic
Where is Salmonella ssp. found?
- - Excretions from sick or infected (but clinically healthy) human or animals
- - Polluted surface water, standing water
- - Poultry, birds, eggs, cattle, sheep
- - Reptiles
- - Contaminated food, especially of animal origin or cross contamination.
Salmonella is chemoorganotrophic: Many foods implicated in infections:
- trouble with unusual isolates because they escape detection through biochemical identification (differential plating media)…modern technologies using molecular genetic techniques are more accurate
What's the problem with Salmonella ssp.?
Very resilient and adaptable to environmental conditions, low and high pH, salt, drying…
Can survive for several weeks in dry environment and for months in water, not destroyed by freezing
Need to Cook foods to 162-167 Degrees (internal temp) to be safe
Prior exposure to environmental extremes can allow for adaptation
and survival in food processing environments!
Hundreds of thousands of reported infections & around 30 deaths in US each year
Enters GI tract…short period of incubation (few hours to about a day…results in intestinal inflammation, diarrhea (sometimes bloody)
- Typhoid, paratyphoid (enteric) fever vs systemic non-typhoid
- 7-28 day incubation typhoid
- 8 to 72 hours for non-typhoid, usually self-limiting
- can be non-symptomatic human carriers
Usually no sepsis unless immune compromised, elderly, infants, transplant pts, HIV...can result in meningitis, osteomyelitis, death..
Can be low infectious dose if in a suitable food environment (micelles) or low immunity or gastric acidity
Name two common species of Camphylobactor spp
- Two common species are
- C. jejuni
- C. coli
- 2 common species: C. jejuni andC. coli
- Curved rods
- Somewhat “fragile” does not tolerate drying , high oxygen, low pH
- Some strains can grow aerobically or anaerobicilly
- Freezing reduces numbers (grows up to 42 degrees C)
Infection produces diffuse diarrheal symptoms, bloody, edematous, and exudative enteritis
- usually self limiting, can be associated with chronic conditions like arthritis, meningitis..(bacteremia)
- associated with Guillain–Barré syndrome
Often associated with consumption of raw milk, but found in most farm animals and domestic animals
Travelers are often infected, found in water and sometimes on produce…some immunity developed against re-infection
Organism needing little oxygen: a tiny organism such as a bacterium, that is capable of living in an environment where there is not much oxygen
Low number of white blood cells. In this course, Nutripenic precautions would mean all food gets cooked to avoid bacteria!
What is EHEC
Enterohemorrhagic E. coli
- Entero - GI Tract
- hemor - Bloody
- rhagic - Diarrhea
Causing blood diarrhea in the GI Tract... ala E.
E. coli (gram neg/pos? shape? oxygen? spore former? optimal growth temp?)
- Rod-shaped bacterium
- Facultative anaerobe
- Non-spore former
- Optimal growth at 37°C (98.6°F)
- Wide variety of substrates, mixed acid fermenter
- Sorbitol negative (93% of E. coli ferment sorbitol)
- Does not hydrolyze 4-methylumbelliferyl β-D-glucuronide (MUG)
Does not grow at 45 °C (113 ºF)
Cannot be isolated using standard fecal coliform methods
Distinguished from other coliforms by ability to ferment lactose at 44°C (fecal coliform test) and its growth and color reaction on specific culture media (EMB Levine’s plate, eosin methylene blue, producing metallic green colonies on the dark purple agar)
Unlike most coliforms, E. coli are usually of fecal origin & presence is confirmation of fecal contamination
- Of colon bacteria:
- Describes rod-shaped bacteria that are normally found in the colons of humans and animals and become a serious contaminant when found in the food or water supply.
E. coli however, are usually of fecal origin so presence is confirmation of fecal contamination
More about Enterohemorrhagic E. coli (EHEC)
Causing bloody diarrhea
Can lead to hemolytic anemia, acute renal failure leading to hemolytic-uremic syndrome
Serotype O157:H7 and O104:H4 (2011 outbreak in Germany) produce a verotoxin (also called shiga-like toxin)
very similar to toxins produced by virulent Shigella species (Shigella dysenteriae, dysentery)
There are hundreds of serotypes of Escherichia coli
most strains are not pathogenic and produce vitamin K in GI tract
Common organism in biotechnology
found as normal flora in intestines of mammals (indicator organisms)
Transmission is fecal-oral….undercooked, contaminated ground beef, swimming in or drinking contaminated water & eating contaminated vegetables
Commensal organism in cattle, swine, deer
Early incidents in the 80’s in Japan and US associated with undercooked hamburger (very virulent low infective does)
Contaminated during slaughter & butchering
Meat should be cooked to internal temp of 72 °C (162-167 °F).
Unpasteurized milk, juice, raw produce, salami & contact with infected live animals, flies, fenugreek seeds
Contaminated foods have no organoleptic changes
Passed person to person, problem in day-care-centers
Disease of lower intestine: a disease of the lower intestine caused by infection with bacteria, protozoans or parasites and marked by severe diarrhea, inflammation, and the passage of blood and mucus
- Affecting organs:
- affecting an organ, especially a sense organ
"E. coli contaminated foods have no organoleptic changes; i.e. we can not see, smell, or feel any difference."
Name one common test for E. coli.
The negative MUG test.
Does not hydrolyze 4-methylumbelliferyl-B-D-glucuronide (MUG)
Define hemolytic anemia
Red-blood-cell anemia: anemia that results from the destruction of red blood cells and may be caused by bacteria, genetic disorders, or toxic chemicals
E. coli causes hemolytic anemia
Define Hemolytic-uremic syndrome
Hemolytic-uremic syndrome (or haemolytic-uraemic syndrome), abbreviated HUS, is a disease characterized by hemolytic anemia (anemia caused by destruction of red blood cells), acute kidney failure (uremia) and a low platelet count (thrombocytopenia).
It predominantly, but not exclusively, affects children. Most cases are preceded by an episode of infectious, sometimes bloody, diarrhea caused by E. coli O157:H7, which is acquired as a foodborne illness or from a contaminated water supply
What is a good use for E. coli?
Often used in genetic engineering such as making human insulin.
Is a good indicator organism of poo
Most strains are not pathogenic, it produces vitamin K in the GI tract
very poisonous: extremely poisonous, infectious, or damaging to organismsmalicious: showing great bitterness, malice, or hostilityirritating: extremely obnoxious or harsh
capable of movement: capable of or demonstrating movement by independent means
With bacteria it means they have flagella
An excessive accumulation of serous fluid in tissue spaces or a body cavity.
Edema in the GI Track aka diarrhea
Of the intestine: relating to or situated in the intestine.