Nutrition and Food Safety

		Vickie Vaclavik, PHD, RD/LD Section Editor, Food Safety Assistant Professor, Department of Clinical Nutrition; UT Southwestern Medical Center at Dallas

Happy, healthy springtime
Posted: May 2004
Source: Vickie Vaclavik, PHD, RD/LD

Well, the wonderful Fall and Winter holidays have come and gone since we last visited! Welcome back! Thanksgiving, Christmas and various significant December ’04 holidays are now past-history. The same is true with New Years. Now, the more recent Valentine’s Day, St. Patrick’s Day, Good Friday and Easter of 2005 have also come and gone! You may agree that there is a lot of food and tradition inherent to many of these holidays, and that the celebrations may be special. Hopefully you were able to enjoy the days without experiencing foodborne illness!

In our last article we had said that bacteria names would come up in foodborne illness discussions, and, so it has! Let’s get started with the three classifications of bacteria. Among the potential threats posed by microorganisms such as bacteria, viruses and fungi, it is the bacteria that are of most concern in food safety.

First, we’ll look at the infection-causing bacteria including Salmonella (number 1 by far), Shigella, Listeria and Clostridium perfringens. Foods supporting growth include poultry, meats, seafood, moist and mixed foods, such as potato or macaroni salads. These foods may be culprits responsible for foodborne illness. (Note: It may NOT be the mayonnaise in the salads that is to blame, because the acidic level of mayonnaise is actually protective against much bacterial growth. Rather, contamination and bacterial growth may be due to the fact that the salads could contain protein, be held warm, and be mixed with a lot of bare hand contact.)

In addition to food identified above, it may also be unpasteurized foods, including dairy products, and foods held for long time that may become unsafe to eat. Symptoms of foodborne infections may include: headache, nausea, abdominal pain, diarrhea, vomiting or dehydration. Usually the incubation time, prior to exhibiting symptoms is long – perhaps 6 hours, 1 day, 2 days or more. Prevention stresses temperature control, in heating, cooling and holding, personal hygiene and avoidance of cross-contamination.

Secondly, other bacteria may contribute to gastro-intestinal disturbances or even death, by causing foodborne intoxication. This is where a toxin/poison from bacteria actually causes illness, and it is generally more immediate in producing symptoms than bacterial infections. Bacillus cereus, Staphylococcus, and Botulism are frequently contaminators in this category of bacteria. The latter anaerobic Clostridium botulinum that may be harbored by the food inside cans.

Once again, foods must be protected – by temperature control, hygiene and no cross-contamination. Symptoms may be of the aforementioned type, similar to Infections, or in the case of Botulism, may list vertigo, double vision or an inability to swallow (more than a temporary nervous condition).

A third type if illness may be caused by a combination of infection / intoxication. Bacteria such as Cl. Perfringens cause a Toxin Mediated Infection. Not to upset YOUR stomach, but … this bacteria is sometimes recognized as follows: it is one that gives you an upset stomach that has you almost wishing you COULD throw up, just to get it over with and feel better! It occurs soon after eating contaminated food.

E-coli 0157:H7 is a type of the numerous E-coli’s that causes infection/intoxication. Illness is not immediate, but rather somewhat slow to show – 12-72 hours following ingestion, and is caused by a toxin. Beyond the nausea, abdominal pain, vomiting and diarrhea, it may cause bloody diarrhea, and even death. It is commonly found in ground beef, therefore ground beef should be cooked to a minimum 155^o F. (Other foods require lower temperatures - typically 140^oF. Higher temperatures are needed for poultry)

Conclusion

Using the expression frequently used to close a matter being discussed, I will say: “There you have it!” In conclusion, we have briefly looked at types of bacteria responsible for foodborne illness, some common food vehicles, incubation times in our body, symptoms and prevention. Three classifications of bacteria were mentioned. Temperature control, good personal hygiene and avoidance of cross-contamination (see last article) really help with prevention of foodborne illness.

So, WHAT do we HAVE? Information, and NOT an illness!

Happy, Healthy Springtime! … until next time!