CHAPTER #18: FOOD BORNE DISEASES

No one doubts the importance of food in our lives. As you learned #earlier, all active living organisms must have a constant source of energy. This energy may be supplied by materials a cell or organism has stored internally (e.g. our fat or carbohydrate) or it may come from an external source in the environment. Food (NUTRITION) supplies two major components of life, ENERGY and THE CHEMICAL BUILDING BLOCKS OF LIFE. Energy is required for the various enzymatic reactions that require an input of energy for the reactions they catalyze. For example, the movements of the muscles in our legs during a race or in our intestines as we digest our latest meal or to draw air into our lungs for breathing all require energy. Those of you who race or otherwise run for pleasure, know that it is recommended that you stock up on carbohydrates the day before a race so that you will have a ready supply of available fuel stored in your liver to supply the #ATP your muscles will require. As you learned in #Chapter VII the glucose, in the form of the polysaccharide glycogen in your liver, is oxidized to provide the energy, as ATP, that your muscles need to keep moving. When you run out of a ready supply of glucose you "hit the wall" and have to begin using other sources of energy.

Food also supplies the structural material required for living organisms to make new macromolecules for repair of damaged structures or for new construction, such as the manufacturing of offspring. That is, food supplies living organisms with the raw materials necessary for cell construction, as well as other essential components of life such as vitamins and minerals. A balanced and sufficient diet must contain all the calories (units of energy) required to maintain life and the materials for cell maintenance and construction. In this country most of us have never suffered any sort of serious food shortage, nor do we even know anyone who has. Sadly, however, there are pockets of poverty, ignorance and life-style choices that result in some Americans being malnourished to varying degrees. In contrast to our food affluence, educated people know that much of the world's population goes to bed hungry and suffers from constant nutritional deprivation of one kind or another. This condition ranges from full starvation to perpetual lethargy to permanent brain damage of millions of people, mostly children. It is further common knowledge that any increase in the world's population requires a commensurate increase in food production or starvation becomes inevitable. There is no way around this cruel, uncompromising formula.

Microbes play a crucial role in food resources. Microbes are responsible for the direct loss of much food through food spoilage and through the destruction of the crops and animals from whence the food comes. If you doubt this, just search the back regions (if you dare) of your refrigerator for those ugly remains of last month's forgotten leftovers (that furry pizza piece from the party last month). Conversely, microbes are responsible for manufacturing, via their biochemical activities, much of the favorite food we humans enjoy. Further, the microbes, again through their biochemical activities, preserve foods so that we can enjoy them at a later date. Finally, through their activities, microbes are vital to maintaining the fertility of the soil; so much so that we would soon starve if the soil microbes were to vanish. The affects of soil microbes on soil fertility will be discussed in chapter XX.

SOCIAL ATTITUDES TOWARDS FOOD

To fully understand food issues, it is necessary to appreciate how much our ideas about food are the result of social training and experience. For example, everyone is aware that different social groups have different food preferences. A brief walk through downtown Pullman (is there any other kind?) will take you past several ethnic eating establishments, offering a tempting variety of cuisine which most of you have probably sampled one time or another. Even within our own country we have regional food preferences such as "Southern Cooking" or "Midwestern Cuisine" etc. However, the different preferences in food across the world are enormous, including Africans that live off of fresh cattle blood and yogurt (they're very healthy), Asians that drink urine-flavored brews, to Eskimos who enjoy rotted fish. Many of you like buttermilk and cottage cheese, but the English consider the latter to be "spoiled milk". Conversely, many English and Scots relish a pheasant that has been hung out at room temperature for several days until it is rather "ripe" (the nose tells you when it is ready). Our local meat counters offer animal intestine and testicles and some students order their pizza covered with small fish that contain their entire gut contents and others enjoy raw fish and raw oysters. Ethyl alcohol, which is the metabolic waste, or urine equivalent, of yeast, is considered nectar-of-the-Gods by people all over the world. Other peoples relish ants, grasshoppers or bees and look forward to the harvest of these culinary delights with the same enthusiasm Americans hold for that Thanksgiving turkey. The bottom line in all cases is that whatever we label "FOOD", provides us with the energy and nutrients we require to maintain life.

FOOD AND HISTORY

Food has played a critical role in history. Archeological evidence suggests that many, perhaps most, ancient civilizations disappeared as a result of losing the ability to feed themselves. The most common reasons cited for this disaster are climate and ecological changes, combined with overpopulation. Conversely, the simultaneous growth in population and the industrial revolution were fueled by new discoveries in agriculture that made it possible to feed many more people a good diet (well fed people do more work and work smarter). In history you have been taught about how the "SPICE TRADE" was the driving force behind the intense burst of exploration that inspired Columbus, among others, to make their long and perilous voyages of discovery. Actually it was the microbes that really provided the impetus for those journeys.

We, in the US, have only had widespread refrigeration available for approximately the last 50 years. When I was a young boy, I remember following the ice-man with my friends as he delivered 50 pound blocks of ice to our "iceboxes" on hot summer days. We children would grab ice chips from the rear of his truck and suck on them (remember, there was no TV in those days). A 50 lb. block of ice, when placed in an insulated icebox would keep the meat, milk and butter cool for several days and retard their spoilage. It wasn't until the 1940's that my home had an electric refrigerator. In the middle ages foods like meat, milk etc. spoiled quickly, particularly on warm days. However, even spoiled meat is nutritious in spite of its rank odor and bad taste, and it beat starvation by a long stretch. Thus people, even the wealthy, frequently ate meat in various stages of active decay and pretended to actually like it. However, they found that if you added SPICES to this rotting meat the strong flavors the spices imparted covered up the rotten aroma and minimized gagging during dinner. Therefore, spices became the "had to have item" for every host who liked to throw parties and impress his friends. Since spices only came from the far east by camel and small, leaky boats, those that survived the journeys were able to command top prices for these prized, gourmet, barfing-preventing items. The large profits involved stimulated an intense interest in finding quicker and safer routes to the source of these valuable spices (does "worth-its-weight-in-gold" mean anything to you?), hence the exploration explosion of the 1400 to 1600s. One might even say that the MICROBES and not Columbus discovered America.

Another role of microbes in the middle ages was that of producing miracles. It seems that the damp, dank churches of the middle ages were perfect incubators for the growth of the bacterium Serratia marcescens in the sacramental wafers. Under these conditions the bacterium produces a bright red pigment that resembles BLOOD, thus the appearance of blood-covered holy bread; clearly a miracle in the eyes of the people of that time. Reference: ASM News May 1994.

FOOD PRESERVATION

As supermarkets were rare during most of human evolution, food was in short supply and fresh food was even more limited. Early man may not have been exactly rocket scientists, but they could tell the difference between really-rotten and not so-rotten food. So when someone discovered a way to preserve food while it still had a reasonably decent taste and odor they were likely considered a hero. What follows is a description of some of the old and new food preservation methods.

HEAT STERILIZATION

One of the problems with war is that soldiers insist on being fed regularly (remember, they hold the weapons). In the early 1800s, Napoleon found that the joy of his life, his large army, could no longer feed itself by stealing from the local peasants and thus his plans to conquer the world were stalled. His solution was to offer a reward for anyone who could figure out how to preserve food so he could take it along with his army, thus keeping them and him happy (the only unhappy ones being those he conquered). In 1810 a man by the name of APPERT found that if he put food in a bottle, jammed a cork tightly in it and placed it in boiling water for an hour or so the contents didn't spoil. BINGO!!, he won the prize, Napoleon got his war, and learned just how seriously cold a Russian winter could get. This procedure, known as STERILIZATION, eventually developed into the canning process. In the process of sterilization all living organisms are destroyed, including bacterial spores. As you will learn later, the most deadly biological toxin is produced by the spore-forming bacterium, Clostridium botulinum. C. botulinum is an #obligate anaerobe that can grow in seal containers like cans and jars, therefore the canning process is specifically designed to destroy the C. botulinum spore. This is achieved by heating food to a minimum of 123^oC or 253.4^oF for 15 minutes.

In the home, sterilization is carried out using a PRESSURE COOKER. Many of you probably have seen your grandmother, or perhaps your mother, using this container to sterilize home-canned food. The pressure cooker works as follows:

In the microbiology laboratory and commercial canning companies sterilization is achieved by using large containers that operate exactly the same as the home pressure cooker. The laboratory instrument is called an AUTOCLAVE. In commercial canning processes the sterilization containers may be as large as rooms and the food is often wheeled in on large carts.

Can you explain the difference between PASTEURIZATION and STERILIZATION. If not go "directly to jail and do not pass GO or collect your $200".

COOLING AND FREEZING

As described above, except for Eskimos and other inhabitants of the far north, cooling has only emerged as a common means of preserving food since the mid 1800s when the ice-making machine was discovered. Prior to that time it was common in northern climes for people to cut large blocks of ice from local lakes and to store them in insulated warehouses for use during the summer months to cool their beer and other food items.

Cooling as a food preservative is utilized at two levels, 7 to 4^oC and -20^oC or lower. The higher temperature is commonly used in home refrigerators. At this temperature, the growth of microbes is slowed down but not stopped. Indeed, some microbes (#psychrophiles) grow optimally at these temperatures. The failure to prevent spoilage at this higher temperature is attested to by anyone who has attempted to use milk older than two weeks in a refrigerator or who has left fruits and vegetables in a 'fridge' for extended periods. At the lower temperature the food is frozen. As microbes are unable to grow in frozen material, freezing is one of the most successful means of preserving food with minimal change in flavor or loss of nutritional value. The major draw back to the use of cooling is that (a) it is expensive and (b) it also preserves many pathogens that happen to be present in the food when it was cooled. As a matter-of-fact the storage of living material at temperatures of -70^oC or lower is the best way of maintaining cells in a state from which they can be subsequently cultured. Such material as sperm, ova, embryos (human and other forms of life), all types of microbes and tissue cells can be frozen and stored for years with little loss of viability providing the procedure is carried out properly.

DRYING

Drying as means of preserving food may very well be the oldest method of preservation known to man. Almost certainly it was an accidental discovery made by our primitive ancestors living on the hot plains of Africa. Most likely, our ancestors frequently came across carrion (a sort of road kill) that had dried in the arid conditions. Being hungry, they ripped off the dried meat and chowed down. It didn't take them long to recognize that it wasn't spoiled, that it was light and that it stayed unspoiled as long as it remained dry. Some budding hairy-Einstein soon realized that fresh meat could be dried by placing it in the hot sun and the human race was off to the races, so to speak.

Drying is employed today as a common means of food preservation by all peoples living in warmer climates. Generally the food, such as fresh meat, is cut into small strips and placed on rocks exposed to the sun, or hung over sticks by a campfire. The pieces must be small so that the food dries fast enough to prevent spoilage. In the case of meat, one trick is to hang it high enough so the flies can't get to it and lay their eggs in it. As the water evaporates and the food dries, the OSMOTIC PRESSURE (the result of hydrophilic molecules binding water molecules) increases to a point where microbes are unable to compete with the water-binding material in the food for the remaining water. Since microbes are unable to grow without free (available) water, the food is safe from spoilage, even though it may retain significant bound-water. In some cases (beef jerky) the food is salted prior to drying. The salt is inhibitory to many microbes and contributes to the high osmotic pressure that prevents microbial growth.

SALTS AND OTHER CHEMICALS

SALT OR SODIUM CHLORIDE: The use of salt as a food preservative is probably as old as drying, if not older. All mammals need salt and they will travel long distances to obtain it. Our human ancestors certainly visited the ocean or salty lakes to collect the salt that had dried on the shore. Occasionally animals or fish must have died in pools of salty water and then dried in the sun leaving their desiccated carcasses impregnated with salt. Again our hungry ancestors were unlikely to turn down a potential meal and they must have quickly recognized that the salted food was unspoiled and remained so as long as it was impregnated with salt. The salted food served a dual role as a source of nutrition and of sodium chloride, and as it dried it was easier to transport. Before canning, salted meat was the staple food on ships that traveled any significant distances away from land (hence the term "ol salt").

NITRATE (NO₃) AND NITRITE (NO₂) (SALTPETER): Nitrate and nitrite salts are used in many foods today as both a preservative and to prevent meat from browning. The bacterium #Clostridium botulinum is an obligate anaerobe in that the presence of even a tiny amount of free oxygen prevents its growth. Yet, C. botulinum readily grows in prepared meats like sausage. Nitrate and nitrite are OXIDIZING AGENTS that are chemically similar to oxygen. As such they, like free-oxygen, inhibit the growth of C. botulinum in foods. In addition, they prevent certain substances in meat from becoming REDUCED, which causes them to turn the meat brown, suggesting that it may be poor quality. In recent years scientists have discovered a link between nitrate/nitrite and the formation of #carcinogens. As a consequence of this the FDA has required the removal where possible of these chemicals from foods or the lowering of their concentration to the minimal level. The use of nitrate/nitrite poses a classical cost/benefit conflict. That is, is the cost (cancer) of using these substances in our food supply balanced by the protection against death by botulism poisoning? Each of us should decide that ourselves don't you think?

SULFITE (SO₂) and VITAMIN C: Most of you have observed the "BROWNING" of fruits and vegetables; the apple, peach or banana you eat turns brown before your very eyes, even as you chow it down. Generally, people feel that "brown" food items are spoiled or at least of lower quality. The browning results from the actions of enzymes in the fruits and vegetables that rapidly react with oxygen to produce brown-colored chemicals that protect the damaged food from microbes; i.e., the brown chemical is inhibitory to many microbes. Sulfite is a powerful "REDUCING" chemical that BLOCKS THE BROWNING RESPONSE, and it is inexpensive, & effective in tiny amounts. Therefore it is common to rinse fruits and vegetables in restaurants in solutions containing SULFITE. This insures that items that were prepared several hours before will remain "fresh-looking" all day long on the customer's plates. At the concentrations used, sulfite is not toxic, but a small percentage of people are highly allergic to sulfite and an exposure to even a tiny quantity of it on lettuce etc. may be sufficient to induce a violent #allergy attack. This is why restaurants often have signs telling their customers that they are using sulfite on their foods. Another powerful reducing agent that serves the same purpose is vitamin C (ascorbic acid). This vitamin also is inexpensive, is effective in small amounts, plus it is beneficial to those who ingest it. However, because it is more expensive than sulfite and it tends to decay faster, it is not universally used.

ORGANIC ACIDS: As you recall, all microbes require an #optimum pH or acidity in their environment to grow. If there is too much acid or base, a microbe will not grow. As the by-products of many microbial fermentations include the production of chemicals like ACETIC ACID (vinegar), LACTIC ACID, and PROPIONIC ACID it is not too surprising to find that humans, and other life, can actually use these substances as nutrients. However, when they are added to foods in sufficient quantities to lower the pH below that which will support the growth of most food-spoilage microbes, they can serve as natural food preservatives. Again, our ancestors recognized that "SPOILED" foods such as milk and certain vegetables, retained their nutrition upon becoming acidic and remained eatable (preserved) for long periods. Thus was born choice food items like yogurt, sauerkraut, pickles, cheese and buttermilk. Artificial acids, like benzoic acid, inhibit the growth of some molds, thus it is added to breads and other bakery products that require long shelf live. In many foods, like the sauerkraut you made in lab, salt is combined with acids to preserve food.

ANTIBIOTICS: Most common antibiotics are inexpensive, stable, safe and effective in small quantities. With their ability to kill or inhibit many microbes, antibiotics might seem the perfect food preservative. However, all is not what it seems. Using antibiotics for food preservation is like using 100 dollar bills for toilet paper; it gets the job done but it is not the best use for that item. As you've learned in #Chapter X, we are in grave danger from infections produced by antibiotic-resistant microbes. The use of antibiotics in preserving food and in animal feeds has been demonstrated to increase the spread of antibiotic resistance between pathogens. Although some action has been taken to limit the use of antibiotics for these purposes, it is still done in many places.

RADIATION:

Atomic radiation is becoming widely used in the preservation of food, although its use remains controversial and frightening to many people. In 1997 the FDA approved radiation as a means of preserving meats. Many of the prepared meals available on the supermarket shelves at room temperature have been sterilized by radiation. Atomic radiation is lethal to all life when used in high doses. To sterilize food by this technique, the food is placed in a protected room and exposed to a high dose, usually of gamma radiation, from radioactive wastes refined from atomic power plants. A dosage that had been determined to be lethal to all microbes, including bacterial spores, is used.

Current studies indicate that increased use of irradiation to destroy contaminating microbes would slightly increase the cost, but it is suggested that the increase in cost would be offset by the reduced loss of stored foods. Use of radiation to eliminate #Salmonella enteritidis contamination from eggs is under consideration.

A new for of radiation involving high energy electrons has been approved and foods sterilized in this way will be on the store shelves early next year. This is NOT radiation from radioactive material, but involves the use of "fast electrons". How well people will accept foods sterilized in this way remains to be seen.

FAQ:

ANSWER: No. There is no residual radiation contaminating food exposed to sterilizing doses of radiation.

ANSWER: Although there is still some debate over this, the vast majority of the available scientific evidence does not support this contention. There is no doubt that the high radiation does induce some chemical changes in the food, but there is no proof that any of these materials are harmful.

ANSWER: Yes. However, I consider every new technology suspect until long use proves otherwise, so I try to keep myself informed on this and other technological matters; I would advise that you do the same.

ANSWER: At least 37 nations have approved the use of ionizing radiation as a means for decontaminating more that 50 types of food. In the US radiation is regulated as a food additive. ASM News 63:350-352 (1997).

EXTRA CREDIT COMMENTARY 18A:
Microwave ovens use a form of radiation to cook the food and its acceptance, without much concern, is almost universal. Recent surveys have shown that when consumers have received correct information about radioactive irradiated food their interest in purchasing products treated with this radiation increased by 90%. Explain your feelings on the use of radioactive radiation as a food preservative? If you had to make a choice between two packages of a food, of the same quality and price, and one was sterilized by radioactive radiation and the other by a conventional method, which one would you chose and why?

DIANA BAKER dmbaker@wsunix.wsu.edu

If the use of radiation is safe and effective, then I think that it is okay to use. I use my microwave every day, I would just make sure to stay current on the data being published about radiation as a food preservative. I would prefer the package of food sterilized by radiation because of its ability to get rid of the bacteria.

Rebecca Pavlicek bpavlicek@hotmail.com

When I was younger I was unlucky enough to catch food poisoning and ever since then I have been a microwave maniac. I microwave everything until it is very well done. I would be more than happy to try any food that has been treated with types of radiation to preserve them because I would rather have to live with some future aliment caused by the radiation then have to again live through a week of sickness caused by food poisoning. Radiation is a simple and quite thorough way to make sure the food is sterile because so far the conventional methods have not had such a great track record with many outbreaks and recalls happening all the time. I want to know my food is safe.

Erin Merk emerk@mail.wsu.edu

I am not sure which package I would pick, the one sterilized by radiation or the other by conventional methods. I use microwaves and have no fear. I have faith in the FDA, and if they have approved the radiation method, I might lean towards buying that particular package. After reading and learning about it, it seems to have had good results in its ability to kill harmful bacteria.

Holly Cutler eatchoklit@yahoo.com

The FDA, universities, doctors, and other scientists have agreed using radiation to preserve food is a good idea. Some doctors even recommend irradiated food because it is the safest as far as preserving is concerned (Bruhn). Even though all of these highly educated people have accepted the radiation treatment I am a little more hesitant because long term effects have not yet been researched. It is fine to be using the technique but the FDA should continue to require labels indicating radiation treatment. I am happy to allow others to try the products and once proven okay in the long run I will feel more comfortable consuming the products.

One of my reasons for hesitation is the FDA has been wrong in the past and I think it is best to wait for side effects. Often time’s companies are in a large hurry to push their ideas/products to market that proper testing does not occur. By waiting I feel I am protecting myself from possible human error.

A second hesitation is that eating radiated fruits and vegetables does not sound appealing to me. Strawberries, oranges, tomatoes, and bananas are just a few items receiving the radiation (Bruhn). A large portion of the fruits and vegetable I eat are home grown without chemicals so the thought of them being radiated causes my taste buds to turn away.

Overall if I had the choice between an item that had been preserved through radiation and one through refrigeration I would choose the refrigeration method. The lack of information on long term effects and the technique being so new are my reasons for choosing that route. I tend to stick with what is old and known to work rather than being adventurous.

Works Cited

Bruhn, Christine. Food Irradiation. 22 Sept 99. http://www.ccr.ucdavis.edu/irr/index.html

Brian Bloomfield bloomfieldbrian@hotmail.com

When I here of the term radiation I relate this word to a story I watched last week on television. The show talked about going back to the testing sights of the first atomic bombs. Even after all of these years they are still finding traces of radiation, and there is nothing growing on the islands near the testing sights.

Even though I relate radiation to this story I would pick the food that was sterilized by radiation. We don’t have to worry about high radiation because foods are given low doses of Gama rays. The Gama rays go straight through the meat and it does not produce heat in the meat. I believe that there are only three types of meat that radiation are used on, and they are beef, pork, lamb, and fish.

The use of radiation has been around for a long time. About forty years ago hospitals used the same process to sterilize needles, and other medical items. In the first week of December 1997 the FDA approved the use of radiation on certain foods. (www.loc.gov/lexico/tgm1/r/Radiation_preservation_of_food.html)

We are looking for new sterilization methods because we are tired of seeing people die over E-coli, and other dangerous bacteria. Places like Jack in the Box, have threaten the lives of a lot of people and have taken the lives of several young children. Every year meat and juices are being recalled because of dangerous bacteria.

The thing we must improve is the handling of meat after the sterilization procedures. We would not need to worry about these bacteria if people started thoroughly cooking there food. People who eat meat that is not thoroughly cooked are asking to get sick or even die. Just like we saw in lab, meat that is not taken care of can produce bacteria that can have harmful affects towards us.

Leah Hurley leah_hurley@hotmail.com

I feel that our society is terrified by the word "radiation" we assume that anything that has been exposed to radiation is bad. I think its great that we have the technology to irradiate food to limit spoilage instead of pumping food full of chemicals or treating it with antibiotics. When food is irradiated we kill the microbes that spoil our food. Irradiating food has not been found to cause harm. Our society can be ignorant when it comes to radiation. I find it interesting that people raise such a fuss about an irradiated apple, yet sit out in the sun and tan all day long. If I had the choice between two packages of food, one having been sterilized by radiation and the other by conventional means, I would have to choose the food treated by radiation. I would choose this because I feel that some preservatives that are used in conventional methods are more harmful that of irradiating food.

Chelsy Leslie ccsb123@aol.com

I think that a lot of people don't know much about atomic radiation, including myself, but most people at least know that radiation is something that can be harmful and view it as something they want to stay far away from. So, I think most people would be very hesitant to eat irradiated food. It just SOUNDS dangerous.

I would hesitate to eat irradiated food, but I wouldn't completely boot out the idea. I think I would just want to find out more about it before I choose to eat all sorts of irradiated products. So, I looked up some information on the Internet and learned a little more about it. There are advantages and disadvantages for irradiated foods. I think one of the big disadvantages of it is that it is a relatively expensive process. I know that I wouldn't buy irradiated food if it was more expensive than normal food. I wash my fruits and vegetables and I cook my meats well, so getting irradiated foods doesn't seem that important to me, at least not enough to pay very much more for an irradiated product. I know safe food handling techniques so I feel a little safer following those than consuming a product that has been treated by a process I'm not sure is even entirely safe.

However, in some places, such as in third world countries, safe food handling techniques are often times not known and are not practiced. Irradiated foods in these countries would be helpful, because it would keep the food supply safer and would help to prevent food borne diseases. The problem with this, of course, is that most of the people in poorer countries would not be able to afford to buy irradiated treated foods.

Although some studies on irradiated foods have concluded that they are safe to consume, I don't feel enough studies have been done, at least not enough to make me feel safe. From the information I read on the Internet from Consumers International, it said that radiation changes the structure of foods in subtle ways. It says, "Consumer experts fear that some of the changes produced by irradiation will affect humans but like with many other subtle chemical effects, the results may not show up for many years." Foods that are irradiated under the recommended doses don't APPEAR to be affected, but that doesn't necessarily mean they are completely safe. I feel more studies need to be done and for a longer length of time.

The advantages of irradiated foods are, of course, that it kills harmful micro organisms (however, it is possible that they might not all be killed) and it prolongs the shelf life by delaying ripening and decaying processes (which helps to reduce food losses).

If I had to make a choice between two packages of food, of the same quality and price, and one was sterilized by radiation and the other by a conventional method, I would most likely choose the conventional one, but I would be open to the idea of foods treated with radiation.

References: http://www.consumerinternationa.org/campaigns/irradiation/irrad1.html

Rachel Silva: rsilva@mail.wsu.edu

Even though there is lots of radiation in using microwaves oven I would have to choose the packaged food that could be tossed in the Microwave and quickly heated up. I would only say this because I am very used to using the microwave as a fast and easy way to warm food. A microwave oven saves time and effort and I think that’s why I would choose the package that could go into the microwave oven.

Ryan Baldwin: butch_85@hotmail.com

If I had to decide between two of the same meat products, but one was sterilized by radiation and the other by a conventional method. I would choose the food product that had been sterilized by radiation. One reason is that the amount of radiation that is used does not make the food radioactive. There is still a lot of controversy about using radiation to kill the deadly microbes, such as Salmonella enteritidis, and E.coli (Micro 101 Net-text). I think that as long as the meat has no radioactive substances and is safe to eat, then there should be no worries. But, if the FDA proves that radiation is harmful to use to preserve the meat from viruses and bacteria. Then it should be taken off the shelves and be made illegal to radiate meat for preservation. However, no one has proven that through the some of the chemical changes in the meat from the radiation, that the chemicals are harmful to humans. I believe that the FDA did a complete thorough investigation on the treatment of radiating meat. Since radiation is probably the most harmful substance out there. Anything living thing that gets into contact with a high dose of radiation will die. If the FDA decided to let the radiated meat out into the public without any tests done, then most likely people would be falling over dead all around the country. I don't think anyone has died yet from eating meat that has been preserved by radiation. If there has, then the government has kept a well secret. Other conventional ways are safe to. But, I don't think that that the conventional ways kill everything on and in the meat. I know I will take my chances with radiated preserved meat then meat that’s been treated the conventional way.

Joey Cottrill joeycottrill@hotmail.com

After reading chapter eighteen on food born diseases, my feelings now are that I will go out and buy products that are treated with radiation. Maybe I'm just the typical American that when you read new information on a certain thing or object, you believe it's true and you overindulge in what ever the correct information might be. I think using radiation as a food preservative is quite all right and yes it may change some kind of chemical aspect to the food or product but I think no one will really taste a huge difference and plus all food tastes the same going down. There would probably be a slight increase in price but I would pay the higher price so I would not be catching some new strain of disease in the food. If I had to choose between two packages of a product that one be used with radiation and the other by conventional method, I would choose the one that was sterilized with radiation. I would feel more comfortable and safe knowing that the food I'm eating has been treated to kill pretty much any kind of microbes and or diseases that may lie in this food.

SALTING/PICKLING/SUGAR:

I have discussed #salting above, but mention it here again because salt is often used in combination with organic acids to preserve foods. As you learned in lab, when making sauerkraut, the addition of salt changes the environment so that different microbes can grow and change the flavor of the food in a preferred way. Sugar is also used in jams and jellies as a preservative. It acts the same way that salt does in that both bind up the available FREE-WATER chemically so tightly that it is not available to most microbes. However, as you've probably all observed when you've opened that jam-jar stored in the 'fridge since last Xmas and found a mass of hairy mold attempting to ooze out of the jar, there are microbes that can grow at high sugar concentrations; they are called saccharophiles (sugar-loving). You learned previously that there are #HALOPHILES that can grow on salted fish and in saturated salt-water.

SMOKING:

Smoking is another ancient means of preserving food. Smoking was probably a serendipitous side effect of the discovery of drying food by the campfire. Our ancestors must have frequently stumbled on the partly cooked remains of animals killed in fires and they certainly tore off the smoked and dried pieces of flesh and ate them. They may have realized then, or more likely, after they had tamed fire, that chunks of food, left in the smoke of the fire while they were off hunting, raiding the nearby tribe or otherwise entertaining themselves, dried out and remained eatable for long periods. Plus the food absorbed pleasing flavors. When foods are smoked they absorb various chemicals from the smoke including aldehydes and acids. The former is lethal to many microbes and the latter, lowers the pH of the meat. There is danger lurking in this process. Aldehydes are carcinogenic and people who eat a heavy diet of smoked foods suffer disproportionately from cancer of the mouth, stomach and esophagus. This is another case of the "dangers of secondhand smoke".

FOOD BORNE DISEASE

Since the nutrients in the foods we ingest are the very same nutrients that microbes thrive on, it is logical that the microbes are among our greatest competitors for the available organic food. For several reasons food borne diseases, or FBD, have always plagued man, and for that matter every other living animal on the planet. First, for most of our evolution humans existed in filth and squalor the extent of which most of my gentle readers can scarcely begin to imagine. Not only were our ancestors (including perhaps our grandparents in some cases) usually covered in dirt and various forms of gore and muck, but our food, often taken from the partly rotted carcasses of long-dead creatures, was covered with even worse. No matter, since our ancestors were hungry--probably near to starving a good portion of the time--the niceties of sanitation were rarely observed. Rather, our ancestors bolted down any food (maggots and all) that fell into their fouled hands regardless of its condition. If they were really lucky they didn't get sick, if they were mildly unlucky they got a few cramps and a brief, but messy case of the runs and recovered. However, if they really had bad fortune they became violently ill and frequently died writhing in agony in their own vomit and excrement. Secondly, many pathogens have evolved to take advantage of the gusto with which humans ingest unsanitary meals to gain entry into our nutrient-rich bodies by hitching a ride in our food for their own nefarious ends. If you think I'm overstating this case just watch an unsupervised small child eat, but don't blame me if you get nauseous.

Recent studies indicate that consumers are very concerned about the contamination of their food with dangerous microbes. In one survey 77% indicated that the fear of "germs" in their food was of greater concern than pesticide residues, product tampering, antibiotics in food or other safety risks. However, despite these concerns, studies show a significant lack of knowledge of consumers as to what constitutes safe food handling practices. These studies show:

The following section will correct these deficiencies and, if followed, will make eating at home as safe as eating out.

Food Borne Diseases exist in two major categories; INTOXICATIONS and INFECTIONS. The former is the result of ingesting toxins produced by microbes that have grown on the food prior to it being eaten. The latter is the result of the food serving as a #fomite that carries an infectious pathogen deep into the juicy recesses of a body where it is able to gain a foothold. Once established the pathogen grows and produces a disease as previously #described. What follows is a brief description, by no means inclusive, of the major FBD including the names of the perpetrators, the disease mechanism, when known, of how they produce a disease state, their prognosis and treatment.

BOTULISM

The CDC has published an excellent

description of FBD on the Internet. I am making the indicated chapters in this "Book" required reading for the next exam. A link to the appropriate chapter is included at the beginning of each of the NetText sections.

Botulism is an intoxication that is caused by the ingestion of a virulent nerve toxin produced by the growth of the gram positive, obligate anaerobe, spore-former Clostridium botulinum. This bacterium appears to be a normal inhabitant of the soil, hence its ready contamination of most foods. It is able to grow in absence of oxygen in a wide variety of foods and in so doing produces a protein neural toxin, two to three grams (an amount equivalent to the quantity of salt in the average salt shaker on your table) of which would be sufficient to kill every human on earth. However, the organism will not grow in the presence of oxygen or nitrate salts and it does not produce the toxin at a pH below 4.7. Only one strain, which is found associated with marine organisms, is able to produce the toxin at refrigerator temperature. The toxin is destroyed by boiling it at 100^oC for 10 to 15 min. However, the spore requires a temperature of 121^oC for 15 min to kill it.

The toxin acts by binding to nerve junctions and destroying the nerve. The symptoms, which occur usually within 12 to 36 hours, but which can take up to 8 days to appear, classically consist of double vision, dizziness, inability to speak, breathe or swallow. Death often occurs due to the inability to breath. The only treatment is the injection of #antitoxin to the several varieties of the toxin. This treatment is only effective against free toxin, as once the toxin has bound to the nerves the damage is irreversible. The entire canning process is built around insuring that all spores of this bacterium contaminating any canned food are destroyed in the sterilization process. Industry has a sterling record in that deaths from commercial-botulism are very rare. This is influenced by the fact that once a product is known to contain botulism toxin none of that product is ever again purchased by a customer. The majority of botulism poisonings occur in HOME-CANNED FOODS prepared by grandma or your favorite aunt. A rule of thumb is "READ THE BLOODY CANNING DIRECTIONS" and if you think a food might contain the botulism toxin never taste even the smallest drop of it!

Q FEVER

This FBD is the result of infection by the gram negative, obligate intracellular bacterium Coxiella burnetii. This organism is associated with farm animals, with man usually considered to be an accidental victim; in fact it was first called the "wool cutters' disease" because Australian wool clippers frequently came down with it because of their close contact with sheep. It is still a common disease among those that work with farm animals where it is spread in the dust and through direct contact with animal carriers. It produces a flu-like disease that varies from being mild to very debilitating. Although the majority of people who contact this disease recover, some strains of the bacterium are able to infect the heart, producing a fatal disease. Because it is highly infectious, the onset rapid and the disease debilitating, it has been studied as a biological warfare weapon. The microbe produces forms which are spore-like in their resistance to heat and drying. Because of the frequency of milk contamination by C. burnetii is considered a FBD and because of the heat-resistant nature of this bacterium, the temperature of the pasteurization process was increased a few years ago to 72^oC for 15 seconds to eliminate it from milk. It so happens that the chairman of our department is one of the world's leading research investigators of C. burnetii and his laboratory has been responsible for developing an improved diagnostic test for it.

STAPHYLOCOCCUS AUREUS FOOD POISONING

As you learned in lab #exercise 20, the gram positive coccus-bacterium Staphylococcus aureus is a common inhabitant of the human body, being found on our skin and in our nose and is considered part of our natural flora. This bacterium interacts with humans in many ways. It is a common cause of #nosocomial infections that frequently causes death in the patients it infects, it is a prevalent cause of severe skin infections like boils and impetigo, it is the etiological agent of TOXIC-SHOCK SYNDROME and it is one of the major causes of FBD in the world because of its intimate association with humans. This bacterium has a number of characteristics that contribute to its many roles. Although it is not a spore-former, it does tolerate high temperatures better than most non-spore-formers. It is able to grow in high salt and sugar environments which allows it to survive and flourish on the human skin and in rich, sweet foods. It produces a wide variety of toxins, depending on the strain and it tends to carry a large number of antibiotic resistant plasmids. It is, in short, a formidable adversary.

It generally produces FBD in "rich foods", such as cakes, pies, potato salad and custards. The usual scenario involves food that was prepared in advance and improperly stored for a long time before being eaten. During this storage period the contaminating S. aureus (from the nose and hands of the individual who prepared the food) grow rapidly, often in such perfusion that their yellow colonies can be observed upon close examination. During growth the bacteria produce a number of potent toxins, one of which, called a SUPERANTIGEN, mimics a protein involved in our immune response. This superantigen acts by over stimulating the #T-cells to produce prodigious quantities of interleukin 2 which, in turn, induces fever, malaise, nausea, vomiting, diarrhea and shock, which are the classical symptoms of Staph food poisoning. This was discovered serendipitously by a physician who was treating cancer patients with interleukin 2 at different dosages and he noticed that at high doses they developed the classical food poisoning symptoms. There is a classical article in the Scientific American Apr. 1992 chronicling this fascinating story.

Staph food poisoning symptoms usually appear within 1 to 6 hours after ingestion and produces the symptoms described above. The disease is usually over within 24 hours and death is rare, usually limited to the very young or the old and infirmed. The best way to avoid this disease will be summarized below. Click here for an EM picture of S. aureus.

SALMONELLA GASTROENTERITIS

Infections of humans by a variety of salmonella species is quite common in the US, being one of the most common causes of foodborne illnesses in the home. Salmonella are a genus of gram negative, small rod-shaped, non-spore-forming bacteria that are usually associated with animals, both wild and domestic. The problem occurs because many of the animal strains of salmonella, including ones that live in snakes, turtles and lizards, as well as chickens, horses, and turkeys, can infect humans and cause a severe gastroenteritis. This bacterium is released in the feces of the infected animal, thus when humans contract this disease it usually means that they have ingested fecal material due to unsanitary behavior. One of the most common sources of human salmonella infection occurs in the kitchen, both commercial and domestic. Unless the HIGHEST STANDARDS OF SANITATION are applied by knowledgeable individuals during the slaughter and preparation of food for human consumption, fecal material can contaminate the food. Such contamination can easily be spread to other foods via kitchen utensils, cutting boards, by contaminated hands or contact with contaminated work surfaces. The salmonella are hardy microbes that are able to survive outside their hosts in water, on moist surfaces etc. for days to months, so cursory measures will not protect you from these dangerous pests.

The most common sources of salmonella infection are fecal-contaminated animal meats such as turkey, chicken, beef etc. and eggs . Victims ingest the bacteria which invades the intestinal mucosa setting up an infection that produces inflammation of the intestine resulting in diarrhea, fever, cramps, nausea, abdominal pain, and vomiting (GASTROENTERITIS). The disease onset occurs within 8 to 48 hours up to several days and the disease lasts 2 to 5 days to as long as several weeks. Treatment involves #fluid/electrolyte replacement; antibiotics are only used to counter secondary infections. A serious, new form of Salmonella has appeared in the US in the past 10 years. This is a disease caused by Salmonella enteritidis. This bacterium has developed the ability to grow in the ovary or egg-producing organ, of chickens where it is deposited within the egg as it is being formed. Other egg-related salmonella are found on the exterior of the egg where they can be killed by washing with bleach or hot soapy water, however this new strain can only be killed by thoroughly cooking all parts of the egg. That is, the bacterium is NOT ELIMINATED from soft-boiled eggs or "over easy" eggs. The disease produced by S. enteritidis has caused a number of deaths and is a threat to anyone who fails to cook their eggs properly. In our household we always cook anything with egg in it thoroughly. The disease can only be prevented by testing of egg-producing flocks and the elimination of all the infected chickens. One common problem is the way in which eggs are stored prior to placement on the store shelves. In a recent investigation it was found that while the FDA rules specify that eggs should be stored at temperatures low enough to prevent the growth of S. enteritidis in them, many handlers do not adhere to these rules and examples of eggs being stored at room temperature in stores for several days were found. Perhaps you should inquire of your supermarket manager how their eggs are stored prior to being placed out for sale.

CLOSTRIDIUM PERFRINGENS

Clostridium perfringens is a gram positive, obligate anaerobic, spore-former that is found in the gut of many animals, including humans. Besides producing a FBD, it is responsible for producing gas gangrene. As with salmonella, C. perfringens contamination occurs via the fecal-oral route during slaughtering and food preparation. However, this disease is an INTOXICATION and not an infection. As with Staphylococcus food poisoning, this FBD is usually the result of improper storage of food prepared in advance.

A typical scenario goes something like this. A holiday turkey is prepared, however during preparation the stuffing gets contaminated with C. perfringens spores (from poop) left on the turkey during their slaughter. The stuffing is subsequently packed tightly inside the turkey. Because stuffing is a excellent insulator, it may not get hot enough to kill the heat-resistant spores. At the first serving of the turkey no disease occurs, however once the stuffing, containing the live spores reaches room temperature the spores germinate and begin to grow rapidly while producing toxins. As the stuffing sits out for several hours before being stored in the refrigerator in a large bowl, bacterial growth continues and since the large mass of stuffing may take several hours to cool down in the refrigerator, growth continues for several more hours. When the "leftovers" are eventually served they contain toxic quantities of bacterial products and the eaters become ill. The illness strikes within 8 to 16 hours and produces profuse diarrhea. Most victims recover in 1 to 4 days and no treatment is usually necessary except for the very young or the elderly.

ESCHERICHIA COLI 0157:H7

Click here for CDC chapter and here for information on the most virulent strains of E. coli.

This is a new kid on the block in that the disease produced by this bacterial strain was first recognized in 1982 during an outbreak of a FBD in the State of Washington. E. coli is a normal inhabitant of the human and animal gut and is the most studied bacterium on the planet. It is a gram negative, motile, plump, non-spore-forming rod. The numbers 0157 and H7 refer respectively to the antigenic characteristics of #LPS (0157) and a flagella protein (H7). Although this strain had been first reported in 1975 it was not recognized as a FBD organism until the 1982 epidemic. It is likely that there had been many previous outbreaks of food poisoning involving this bacterium, but the etiological agent had not been recognized and the FBD had been blamed on other organisms. This bacterium enter its victims via the fecal-oral route and produces and infection in the victim's intestine. 0157:H7 contains a plasmid that carries the gene for a virulent toxin. Once the infection is established, the toxin is released, causing HEMMORRHAGIC COLITIS and HEMOLYTIC UREMIC SYNDROME. The former results in damage of the intestine accompanied by bleeding and in severe cases destruction of the intestine that can only be stopped by surgical removal of the infected tissue, often several feet of it. In the latter syndrome (HUS), the kidney is severely damaged and often completely destroyed. Death results from general organ failure due to a combination of the toxin effects and the failure of crucial organs.

The bacteria resides in food (and water) that is contaminated with fecal material, usually from cattle, although other sources may exist, including humans. The bacterium is easily killed by heat, but if products like hamburgers are not heated so that all parts of the patty reach a lethal temperature, the organism can survive to cause the disease. This bacterium has been cultured from raw milk, cheese, turkey roll sandwiches, chicken, pork, and raw vegetables; and recently in unpasteurized fruit juice. It has been spread between children at nursery schools due to unsanitary conditions. The onset of the disease occurs 24 to 72 hours after ingestion. It varies from a mild gastroenteritis to the severe, often deadly course described above. Antibiotics seems to have little effect probably because once tissue damage sets in the blood supply is interrupted which prevents the drugs from reaching the infected sites. Surgical removal of the infected tissue is useful but very traumatic and it may not remove all the infection. It appears to be more severe in small children, possibly because they have not developed general low level immunity to E. coli.

The extent and seriousness of this disease was painfully illustrated by events that took place in Japan during the summer of 1996. Almost 6,000 people became ill with 0157:H7 and to this day the source of the infection is unknown.

TRAVELER'S DIARRHEA and OTHER E. coli INFECTIONS

The bacterium E. coli is the etiological agent of a whole range of water and food borne diseases. One of the more common is a disease known as TRAVELER'S DIARRHEA. As its name implies this disease usually hits a traveler 1 to 3 days after he/she has arrived in a foreign country and consists of everything from a mild case of loose stools to a full blown case of painful diarrhea where one is confined to staying within 10 feet of a toilet until it passes. The symptoms usually disappear within 1 to 3 days and it is treated with anti-diarrhea drugs. A traveler may suffer subsequent attacks as they visit other countries or they may never suffer an attack. The disease is thought to be a result of the strain specific nature of local E. coli. That is, because of a variety of environmental factors E. coli in different populations accumulate a unique series of genetic characteristics to which the infected population is adapted. However, a visitor who eats the local fecal-contaminated food and/or water picks up this unique regional-strain quickly. As it reproduces in the visitor's intestine it produces slightly different set of toxins to which the new host reacts unfavorably, as evidenced by their developing a case of the trots (or as it is called locally, the Palouse Two Step).

A number of other pathogenic E. coli strains have been identified each of which produces its characteristic intestinal disease. Some of these strains are virulent, and can produce a fatal disease while other produce relatively mild diseases. Each strain has been identified by a variety of characteristics including their antigenic "fingerprint", the plasmids they contain and now their DNA fingerprints. The E. coli induced diarrhea is a major, if not the major cause of death around the world of young babies. Usually the babies catch these organisms through drinking contaminated water, often used to make their formula. One of the unintended consequences of introducing baby formulas into underdeveloped countries is an increase in infant death from diarrhea as the mother switch to formula made with contaminated water from breast feeding.

CAMPYLOBACTER AND TRAVELER'S DIARRHEA

The Campylobacter are aerobic/microaerophilic gram negative, motile helical bacteria. They were not recognized as human pathogens until 1970 and yet they are now known to be one of the major causes of gastroenteritis in the world. Some scientists now feel they have evidence that suggests that Campylobacter infections are the major cause of TRAVELER'S DIARRHEA. In the US they cause >2 million illnesses each year and thus are responsible for more foodborne illnesses than salmonella and Shigella combined. Their reservoir is the intestinal tract of cattle, sheep, dog, cats and poultry. Humans become infected primarily through the ingestion of milk, meat or by contact with infected humans. The symptoms of the disease are diarrhea, sometimes bloody, abdominal pain, occasionally fever, and vomiting.

The immunocompromised elderly, particularly those in institutions like nursing homes, are especially susceptible to this organism. That is, the combination of a susceptible population plus spread through a common kitchen and other facilities and personnel has resulted in institutional epidemics. The disease occurs 2-5 days after infection and lasts 7-10 days. It is generally self-limiting in healthy patients, but is life-threatening in the infirmed. Antibiotics are effective in shortening the course of the disease.

It is generally spread by poor sanitation within the home or institution, particularly via the kitchen. The high degree of contamination of poultry with Campylobacter, and other foodborne pathogens, requires that extra care be taken when preparing meals with poultry on the menu.

One of our faculty members, Dr. Mike Konkel and his team are actively engaged in investigating the pathogenic mechanisms of the Campylobacter. In the Fall of 1997 they purchased a number of chickens locally and found that everyone of them was contaminated with Campylobacter; this should be a warning to you. A recent report by Consumers Research (1998) found that 50-90% of the chickens, from a variety of suppliers, purchased at supermarkets were contaminated with this bacterium. Your working assumption should be that "every chicken and turkey" you buy is contaminated.

THE PREVENTION OF FBD or MOMMIE WAS RIGHT (AGAIN!)

The prevention of FBD is theoretically easy but practically difficult due, as in the case of STD, to the nature of humankind. Basically the elimination of foodborne diseases requires rigorous application of basic rules of hygiene and sanitation that everyone learns in kindergarten but frequently fails to apply in everyday life. Your MOMMIE told you all the following and she was cool:

All of these suggestions add up to one thing: AVOID EATING LIVE FECAL MICROBES unless they are well cooked!

MODERN PROBLEMS OF FOOD SAFETY

Modern issues of food safety revolve around two relatively NEW situations: FAST FOODS and PREPARED FOOD.

FAST FOODS AND PEOPLE:

Typically, Fast Food businesses hire young, untrained people who don't understand the significance of routine sanitary measures and who work for low wages. Further, a large turnover in these jobs means that trained individuals are constantly being replaced with new, untrained personnel. As these businesses emphasize speed, profit, and service efficacy, matters relating to hygiene (e.g. hygiene training) can easily be overlooked or even viewed as an impediment to higher profits.

FOOD	PATHOGEN	RECOMMENDATIONS
HAMBURGERS: Fecal matter may contaminate the beef during butchering and be spread throughout the meat by the grinding process. 1 to 3% of cattle carry O157:H7.	Escherichia coli 0157:H7 is currently the major concern with hamburgers. However, other bacteria such as Salmonella sp. and Listeria sp., may cause problems. Roughly 1 in 500 to 1,000 burgers harbors the E. coli strain & the infection rate of people eating ground beef is ~0.05%. The last large outbreak of E. coli O157:H7 in burgers was in 1993, however ~1,000 people became ill & two died this summer in an outbreak caused by well water contaminated with cattle feces.	Stringent sanitary/safety procedures have to be maintained throughout the butchering and meat distribution. USDA is testing new techniques to detect 0157:H7 in beef. Burgers should be cooked so that all the meat reaches a temperature of 160^o F (medium). It is not possible to tell from the color of the cooked meat if the proper temperature has been reached. Raw meat (hamburger) should be strictly segregated from all other food during food preparation & everything (hands etc.) that has had contact with the meat should be immediately disinfected. Susceptible individuals (children and elderly) should avoid eating burgers when eating out.
LUNCHMEAT & HOTDOGS.	Listeria monocytogenes is the major problem with these food. Last year (1998) there were 15 deaths, 6 miscarriages & >100 made ill with L. monocytogenes. 13 companies pulled contaminated meats; one recalled 30 million franks. Listeria is widespread & survives on rubber & stainless-steel surfaces. It also grows at refrigerator temperatures. Listeria is found in 1 in 40 ready-to-eat meats.	Although most of these foods are precooked at the plant, contamination usually occurs because the heating was insufficient or due to unsanitary practices before packaging. Lunch meats should be heated before eating until they steam, but not in the microwave. Do not buy or use lunch meats or hot dogs after their expiration dates.
EGGS	Salmonella sp., particularly S. enteriditis, are the major organisms involved. The latter bacterium is often found inside the egg & is not killed by washing the shell. The number of infections of Salmonella continues to rise, but the risk is still low; 1 in20,000 eggs.	Keep eggs refrigerated & cook until yolks are firm. Look for pasteurized eggs and never eat uncooked eggs or products (e.g. hollandaise sauce, eggnog or mousse) containing uncooked eggs. Only buy eggs from refrigerated cases & use them within 3-5 weeks. Keep them in the coldest part of the refrigerator (not in the door). Check for "USDA" symbol which means the eggs were not repackaged & relabeled. Wash shell with mild bleach & discard cracked eggs.
RAW SPROUTS	*Mostly Salmonella* sp., but some E. Coli O157:H7. More than 1,000 cases since 1995.** Sprouting conditions are optimum for the growth of these bacteria. Source: seeds contaminated with manure, from rodents or dirty water. Many of the sprouting facilities have been found to be unsanitary (sheds, old trailers).	DO NOT EAT RAW SPROUTS unless they have been treated to kill any bacteria (e.g. radiation). Submerge the sprouts in boiling water for 10 seconds and drain on a clean paper towel. If desired, chill before eating.

FAST FOOD, BULK FOOD AND OVERSIGHT PROBLEMS:

Fast Food services usually use bulk foods supplied from a central source over which they have no control. Although food services are regulated by state, federal and local health organizations trained inspectors are few, making oversight spotty at best. Since the report of unsafe food being supplied by a business or sold by a Fast Food franchise, usually causes a boycott of that business, and/or endless lawsuits, it is ultimately in the interest of the owners and employees of these businesses to maintain high standards of health and safety. However, the local staff have no control over how the bulk food suppliers prepare the food, where they obtain it, their sanitary conditions or the long distance carriers that transport the prepared food to them.

POSSIBILITY OF BULK FOOD ADULTERATION:

The issue of bulk food production and transport unfortunately offers ample opportunity for both accidental and intentional food adulteration. The vehicles that transport food are sometimes used to transport hazardous or contaminated materials between carrying food. Since cleaning vehicles between jobs is expensive it may not be performed properly, if at all ("Hey, kid clean out this tanker while I go have a beer"). Further, proper temperatures may not be maintained during food transportation; refrigeration can fail while the driver is asleep, excessively hot weather can overwhelm a refrigeration unit's capacity etc. As was seen in 1997 with the meat packer that supplied E. coli O157:H7-contaminated hamburger to 1,000s of stores and fast food outlets, it is easy for a huge quantity of bulk-prepared food to become contaminated and then to be transported anywhere in the world. Storage conditions after preparation may be unsanitary: rodents and insects may contaminate the food; refrigeration may fail; polluted water sources may contaminate the stored food etc. With increasing world trade, where foods of all kinds flow freely between countries, it is virtually certain that contaminated foods can rapidly spread globally. It has been noted that foodborne pathogens seem to appear virtually simultaneously all over the world. People expect fresh fruits and vegetables all year round so these produces are imported from countries that often have far less stringent sanitation rules and habits than we do. A single meal may contain food obtained from many countries so it is difficult to determine the source of contamination.

THE MICROWAVE ISSUE

The ubiquity of the MICROWAVE in our kitchens also has added a set of new problems and concerns about the microbial safety of our food supplies. The supply of prepared, sterilized foods stored at room temperature on the supermarket shelves presents a potential source of microbial contamination. Frozen foods for microwave preparation have been available for a number of years and have been the source of some problems. Microwaves work by heating up the WATER molecules in the food. This means that if any portion of the food is dry, like potato skin, it may not be heated sufficiently to kill the pathogens residing there. Another problem with microwaves is the uneven distribution of the microwaves. That is, depending on the design of the particular brand of oven, not all parts of a food are heated equally thus some areas of the food fail to reach the temperatures which are lethal to pathogens in those portions of the food. A number of food poisoning cases involving frozen microwave foods have been traced to this problem. That is, in several cases parts or areas of the food were heated properly, but other parts had not reached sufficient temperature to kill contaminating microbes. Microwave instructions inform the user that it is necessary to allow "STAND TIME" so the heat from the heated portions can diffuse to the unheated areas; but the rushed nature of our busy lives makes it difficult to follow these instructions. However, it is better to take the time than to lose 5 feet of your small intestine and half your kidney function to E. coli 0157:H7 isn't it? Some medical authorities and nutritionists are concerned that, because of these problems, microwaves are not very safe. It is up to you to decide. At the very least you should find out how well your microwave model distributes the radiation and what foods should or should not be cooked in these instruments.

OTHER FOOD BORNE DISEASES

There are a number of other FBD that I have chosen not to discuss. These are included in the Bad Bug Book. All are serious diseases.

For a thrill view Trichinella spiralis (Trichinellosis or trichinosis): You may never eat bear again.

EXTRA CREDIT REPORT ON HEREDITARY DISEASE AFFECTING SOMEONE YOU KNEW/KNOW

Copyright © Dr. R. E. Hurlbert, 1999.
This material may be used for educational purposes only and may not be duplicated for commercial purposes.
SCIENCE HALL, ROOM 440CA
PHONE: 509-335-5108
FAX: 509-335-1907
E-mail address: hurlbert@wsu.edu or hurlbert@pullman.com
OFFICE HOURS: Mon. Wed.. 2 to 4 PM.

RECENT FOODBORNE OUTBREAKS IN THE US
DATE	MICROBE	FOOD	#ILL/#DEAD	COMPANY	LOCATION	REFERENCE
6/24/98	E. coli	POTATO SALAD	4,500/0	NA	CHICAGO	Intelihealth
4/6/99	O157:H7	HAMBURGER	7/0	Rochester Meats	EAST US	LMT
4/6/99	LISTERIA	HOT DOGS & DELI MEATS	NA/15 + 6 MISCARRIAGES	BILL MAR FOODS	EAST US	LMT
4/7/99	LISTERIA (SUSPECTED)	SALMON DIP	0/0	PERONA FARMS	NJ	AP
6/7/99	SALMONELLA	ORANGE JUICE	207/0	Sun Orchard	15 STATES + CANADA	Intelihealth
8/99	O157:H7	Lemon Aid	>1000/3	NY Fair	NY State	NBC News
8/99	O157:H7	Drinking Water	>100/0	Party	IL	NBC News

MICROBIOLOGY 101 INTERNET TEXT

CHAPTER XVIII: FOOD MICROBIOLOGY, FOOD BORNE DISEASES

UPDATED: 01/30/02

GLOSSARIES

TABLE OF CONTENTS

INTRODUCTION