In This Update:  

E. coli Infections Up in South Dakota

New Life For Food Irradiation

Irradiation preserves T cell responses in bacterial vaccine

E. Coli Infection Prompts Lawsuit Against Massachusetts Grocery Chain

Philippines Mangoes Get Green Light for USA Market

USDA Proposal Worries Hawaii Fruit Growers

Radiation-Killed Bacteria Induces Broad Immune Response in Mice

With Competition and Costs, Airfreight Ain't  Easy

South Dakota state health officials were cited as saying that reported cases of E. coli infection in South Dakota in 2006 are slightly higher so far this year, and that 16 cases of E. coli have been reported so far thhis year, compared to 13 reported by the end of July 2005.

State epidemiologist Dr. Lon Kightlinger was cited as saying people should take precautions in handling food and to practice good hygiene to avoid infection. Kightlinger was further cited as saying 60 percent of South Dakota cases in 2006 have been children younger than 20 years old, and 25 percent of cases are children three years old and younger. Three of the E. coli cases have resulted in HUS, all in children 13 years and younger. There have been no deaths.

There's a new company in the microbial control industry that plans to reinvigorate the use of irradiation for ground beef and chicken. It's counting on a more informed public, and it is ready to promote the benefits of the technology's ability to reduce the microbial load on those products and make them even safer for consumers. The company's debut may signal a resumption of the upward curve for irradiation of meat and poultry that looked so promising just a few years ago ó and then took a crippling hit when the high-profile SureBeam Corp., owned by Titan Corp., sought protection in bankruptcy in January 2004, and never reemerged.

The new company is Sadex Corp., Sioux City, Iowa, and its principal, David Corbin, purchased the assets of SureBeam in June 2005, outfitted the Sioux City, Iowa, irradiation facility with the SureBeam technology and uses the SureBeam electronic-beam (e-beam) method. He was able to tap the expertise of Bruce Miller, Ph.D., who has a consulting company, EBM LLC, and had been vice president for technology development for SureBeam. The Sadex e-beam irradiation facility is in operation and ready for increased volume, and Corbin is considering a second site in Texas. Corbin is an entrepreneur and a believer in irradiation's benefits and potential, but also a realist about the technology and its potential in the meat industry.

Sadex does feature some procedural changes to make the technology more efficient, and they deal with the material handling systems, Corbin tells Meat Processing. "It took long periods to time to set up new runs, and we've cut set-up times down considerably. If you're not getting product in front of the beam, you're not making money. The new procedures make it easy to set conveyor speeds and get the load going on the machine." He says that set-up time between loads is down to 12 minutes from the earlier 45 minutes. "We can handle many more loads a day now," he says.

"David is really thinking about the business aspects of this [venture], and Ö[is] more realistic about the marketing of it than we at SureBeam were," Miller tells Meat Processing. Miller, who has written a book on the technology, "Electronic Irradiation of Foods," published by Springer, says that he's found from his research that food irradiation is the most studied food processing technology that exists and that "even the World Health Organization says that food irradiation is safe [for food] up to incredible doses, so much higher than would be normally used in meat processing."

Irradiation application is measured in kiloGrays (kGy). In its proposed rule in the Feb. 24, 1999, Federal Register, USDA proposed that the maximum dose of irradiation for frozen ground beef be set at 7kGy. The maximum dose the industry uses is 4.5kGy for ground beef and 3kGy for chicken. "Food is most often irradiated commercially to extend shelf-life, eliminate insect pests, or reduce numbers of pathogenic microorganisms. Food irradiation for these purposes is practiced in many countries, including the United States," the Federal Register notice explained.

Cliff Albertson, general manager and COO of Huisken Meat Co./A.J.&R Co., Chandler, Minn., one of the pioneers in irradiation of ground beef, tells Meat Processing that by combining Ecolab's Sanova antimicrobial process, which is sprayed on all of Huisken's beef trimmings and irradiation, the company currently accomplishes up to a 6.5 log reduction of bacteria on its product, "essentially 95 percent." The Sanova treatment gives between one and 1.5 logs reduction, and "with irradiation we get five logs more," Albertson explains.

Albertson has had strong support in his pro-irradiation position from Ron Eustice, executive director of the Minnesota Beef Council, who is an advocate of irradiation. Eustice travels internationally promoting irradiation for meat and produce. Mangos coming out of India and papaya coming out of Brazil and much more is being irradiated. Some of this is to replace a toxic chemical that is making produce workers ill, but irradiation is making these foods safer, too, he comments. "I'm aware of 21 irradiation facilities that are proposed or under construction around the world. Australia, Brazil, China, India, Indonesia, Korea, Malaysia, Pakistan, Peru, Philippines, Thailand, and Vietnam are among the countries using irradiation, according to Eustice.

A few upscale retailers had been selling irradiated meat and more had been at the cusp of adding the ground beef that could offer the promise of safer hamburgers, at least for test purposes, to a public was fearful of E. coli O157:H7 when we last covered this subject in 2002. Suddenly, with the demise of SureBeam, processors and retailers were left without sufficient irradiation facilities to get the job done economically. Most of the marginally committed firms abandoned it. But for the principals of three large companies, the Schwans Food Co., the Marshall, Minn.-headquartered home delivery service, Omaha Steaks, the Internet meat retailer headquartered in Omaha, Neb., and Colorado Boxed Beef, Auburndale, Fla., which had committed to selling irradiated ground meat, going backwards wasn't an option. Though SureBeam was gone, there was still irradiation services offered by Food Technology Services, Mulberry, Fla., and at Texas A&M University. Truckloads of ground beef products began heading to both facilities.

"We actually started irradiating our ground beef in the fall of 2000," Beth Weiss, Omaha Steaks' corporate communications director, told Meat Processing. Bruce Simon, president and fifth generation member of the family owned company, was the catalyst. "Bruce feels very strongly that we want to do anything that we can possibly do to insure the food safety of all of our products. Of course, ground beef is the one that has the greatest risk." She noted that Simon understood that thorough cooking kills any surface bacteria, but with ground beef, the surface meat is ground and moved inside, creating its own environment to harbor problems. "He wanted to start irradiating the ground beef because he did not want anyone to ever have an E. coli scare based on something that they ingested from Omaha Steaks.

Weiss agrees that the decision became more complicated when the "only-two-hours-from-here" SureBeam, Sioux City, Iowa, facility closed. To find an alternative operation that had the capacity available that the company needed, Omaha Steaks began shipping its ground beef to Mulberry, Fla., and then bringing it back. "It adds about five days to the total process," Weiss adds.

What is Irradiation?
Irradiation comes from ionization, that is, energy-activated electronic particles, which are able to forge a break in a bacteria's DNA, either killing it or crippling its ability to multiply and grow. Bruce Miller explained it to Meat Processing.
Electronic ionization happens every day in our lives, Miller says, from using a microwave oven to what happens in an ordinary neon light bulb. To illuminate a neon bulb, "there's a electronic discharge and it ionizes the neon gas. When the electrons fall back into their atomic orbit they give off energy and light," he says, adding that this level of ionization is simply one in an accelerated progression of particle activity. "The particles we use for food irradiation are quite energetic. You don't encounter them naturally, and you reach them as you work your way up in the spectrum toward the ultra violet range. You start being able to ionize x-rays and gamma rays [from Cobalt-60] quite easily." It is the ionization that does the damage to the DNA, he explains.

By 1992, irradiation using e-beam, Cobalt, or x-ray had been approved by both the Food and Drug Administration and USDA to control Salmonella. By 2000, both agencies had approved the technology for use on raw beef. It's been six years, and the technology that could have been in place and helping save lives is still waiting for the door to the industry to open wide. Meat Processing celebrated the opportunities it promised in 2002 (February, page 18), yet things happened to preclude that occurring. Little of the nation's ground beef or chicken supply is protected today by this proven anti-microbial technology. Richard Hunter, president and CEO of Food Technology Service, estimates that approximately 18-20 million pounds of ground beef and poultry are being irradiated in the United States today. "We are in excess of 10 million pounds ourselves," he adds.

Numerous factors contributed to irradiation's continuing relatively small share of the antimicrobial treatment segment of the meat and poultry markets. Logistics, trashing by ill-informed activist organizations, and resistance from processors and some industry organizations that anticipated having irradiated beef in the meat case with regular ground beef would give the irradiated product a perceived premium position ó and cost.

The highest of the hurdles for broad use of the technology was logistics. Food Technology Service, a Cobalt-60 facility, is in Florida. An e-beam facility built by SureBeam was in Sioux City, Iowa. There were some research opportunities at Kansas State University, and Texas A&M irradiated product, too. Irradiation facilities are expensive to erect because of the thick interior barriers they need to ensure that the radiation is contained. There are perhaps close to 40 irradiation e-beam, Cobalt-60, and x-ray facilities in the United States today and many others worldwide. They have been sterilizing medical equipment, animal feed, and spices primarily and didn't have the set up or capacity for meat. SureBeam began to build more facilities for meat irradiation in other locations for the convenience of meat processors, but in the end, there were not enough meat processors that were willing to take that leap of faith in their consumers.

Misinformation
John Stossel, CBS news journalist who has brought down some popular icons with his in-your-face approach to reporting, addresses the myth about food irradiation in his book "Myths, Lies, and Downright Stupidity: Get Out the Shovel ñ Why Everything You Know is Wrong," an expansion of a television program he'd presented on CBS-TV. One of his myths deals with irradiation:
"MYTH: Radioactivity is deadly; keep it away from food!
TRUTH: Food irradiation saves lives."

The "me-too" popular media gobbled up all of the negative and scientifically unsupported material the technology's activist opponents could create, and spread it in a thick fog over the existing science. One of those groups, Food & Water, was among the most vocal. For his book, Stossel interviewed the group's founder Dr. Walter Burnstein, an osteopath with a family practice, and his associate Michael Colby. Food & Water claimed that a credible study in India reported that irradiated food has caused "testicular tumors, chromosomal abnormalities, kidney damage, and cancer end birth defects." Stossel, who had telephoned the author of the study, confronted the two with the author's denial of the truth of their claims. They said the scientist was unable to stretch her results to the conclusions they had reached because she was one of the "pure scientists and she doesn't' want to make that break."

Stossel goes on to quote the Centers for Disease and Control statistics that if 50 percent of American meat were irradiated nearly "a million cases of bacterial infections could be avoided and 350 lives could be saved every year." The American Medical Association and the American Dietetic Association have also endorsed irradiation of meat and poultry, Hunter says.

But meat industry officials, fearful of consumer backlash if they embraced irradiation still sit in the wings and watch. Other antimicrobial tools have been developed, to be sure, but few have the power of irradiation to make ground beef safe. Those few companies that believed in the technology and have taken the plunge, included a small Florida restaurateur who insisted that the chicken he served be irradiated so he wouldn't have to worry about safety.

The ride from here should be an exciting one for Sadex, Food Technology Services, and anyone else who decides to jump on board. Imagine a possible 350 lives saved if processors embrace irradiation! Interestingly enough, the opponents of irradiation have made many of the same doomsday arguments that opponents of pasteurizing milk made decades ago. Today, most milk is pasteurized. Perhaps in the not to distant future, all ground beef will be irradiated too...and it should be. MP
 

Sources of Irradiation
There are three sources of irradiation approved for food: Cobalt-60, electron beam (e-beam), and x-ray. Cobalt-60 and x-ray are deep-penetrating technologies that can treat whole cases of product at once. Cobalt-60 is slow; x-ray is fast. E-beam offers shallow product penetration, but it offers more flexibility than the other two irradiation sources.

Comparison of Technologies

• Cobalt-60 offers a simple, predictable, reliable source of highly controlled energy. Its power output is consistent and constant; it cannot be shut off. It has low service requirements and high product penetration.
• E-beam offers on/off technology run by electricity in a relatively compact unit. It will irradiate low-density products at high speeds. Product penetration is limited.
• X-ray offers all of the benefits of e-beam irradiation, plus x-ray penetrates products as deeply as Cobalt-60.

Using gamma radiation to inactivate bacteria for the preparation of vaccines, instead of traditional heat or chemical methods of inactivation, appears to create a vaccine that is more effective than so-called "killed" vaccines against disease, and has the added advantage of a longer storage life than "live" vaccines, according to researchers at the University of California, San Diego (UCSD) School of Medicine. Their findings, published in the July 26 issue of the journal Immunity, could result in more potent vaccines that are relatively inexpensive to produce, easy to store, and that can be transported without refrigeration.

In experiments with mice, the researchers, led by Eyal Raz, M.D., Professor of Medicine at UCSD's School of Medicine and Joshua Fierer, M.D., UCSD Professor of Medicine and Chief, Infectious Diseases Section, VA San Diego Healthcare System, demonstrated that a vaccine made with irradiated Listeria monocytogenes (LM) bacteria provided much better protection against disease than vaccine made from heat-killed bacteria. Listeria is a food-borne pathogen that can cause severe meningitis and systemic illness in immuno-compromised individuals. It is on a list of agents that could potentially be used in bioterrorist attacks, compiled by the National Institutes of Health.

To test the irradiated LM, mice were vaccinated with either heat-killed or irradiated vaccine, and then given lethal doses of LM bacteria. All of the unvaccinated or heat-killed vaccinated mice died, but 80% of those vaccinated with the irradiated vaccine survived. Protection against infection lasted more than one year after vaccination with irradiated LM.

"Irradiation is a technically simple process that retains structural features of the bacterial pathogen without destroying the natural antigens or the intrinsic adjuvants. Therefore, a strong immune response is induced in the vaccinated host," said Sandip Datta, M.D., assistant professor in UCSD's Department of Medicine and lead author of the study.

The inactivation, or attenuation, of pathogens has been a strategy for vaccine development since Louis Pasteur first attempted vaccinations nearly 150 years ago. Vaccines are designed to stimulate the immune system to protect against micro-organisms such as viruses or bacteria, by introducing a small amount of the virus or bacteria into the body. When this foreign substance invades the body, the immune system activates certain cells to destroy the invader. If the body is re-invaded by the virus or bacteria in the future, the memory cells will be reactivated and respond faster and more powerfully to destroy the virus.

Immunization with attenuated live micro-organisms promotes a strong immune response, but there are safety, storage and transportation issues with these live vaccines. Immunizations using killed bacteria are very safe, but they don't work as well in eliciting a protective immune response.

"Irradiation destroys the DNA, making the bacteria unable to replicate so it cannot establish an infection," said Raz. "But some residual metabolic activity may survive, so the irradiated bacteria can still find its natural target in the host."

The researchers further showed that, unlike heat-killed bacteria, irradiated bacteria retain the ability to activate the immune system through Toll-like receptors. Toll-like receptors detect signature molecules produced by microbes and help hosts recognize they are under attack by bacteria and trigger an inflammatory response against the bacteria. These receptors are the "sentinels" of the body's innate immune system, and they activate the acquired immune system that provides long-term, specific immunity against a pathogen. The ability of Listeria to activate these receptors appears to be intact after gamma-irradiation.

The researchers speculate that heat-killed bacteria may target an entirely different pathway, because the bacterial molecules that engage these surface cell receptors have been destroyed.

Vaccination with a freeze-dried powder formulation of the irradiated bacteriañ a product with the potential to be easily and inexpensively stored and transported, then reconstituted just before use ñ was also shown to protect mice against lethal infection.

These findings could result in the mass production of more affordable, more effective vaccines for resource-poor regions where vaccines are most needed. The technology could also greatly expedite vaccine production and distribution during epidemic outbreaks, bioterrorist attacks or other biothreats, according to the researchers.

"The resulting vaccines using irradiation might be the next-best approach, after those produced using live bacteria. But they would be very safe, simple and inexpensive to produce," said Raz. "This might not be the ideal vaccine, but its practicality is beyond imagination."

The research team is experimenting with several other bacterial strains in addition to LM. They noted that there is a potential that the process may also work to produce a vaccine against Staphylococcus aureus, an important human pathogen that causes drug-resistant staph infections.

###

Additional contributors to the paper include Tomoko Hayashi, Samuel S. Shin, Ivan Mihajlov, Agnes Fermin and Donald G. Guiney from the UCSD Department of Medicine; and Sharon Okamoto of the San Diego VA Medical Center.

Funding for the project was provided by the National Institutes of Health.

CONCORD, NH (July 10, 2006) A lawsuit was filed  against Quincy, Massachusetts-based Stop & Shop, a subsidiary of Ahold USA, on behalf of an eight-year-old boy who became ill with a severe E. coli O157:H7 infection after eating ground beef purchased at a Manchester, New Hampshire, Stop & Shop. Marler Clark, the Seattle law firm that has successfully represented hundreds of E. coli victims, filed the lawsuit on behalf of Hercules ìEricî Tsirovakas and his parents, John and Christina Tsirovakas, of Epsom, New Hampshire. The complaint, which was filed in United States District Court in Concord, New Hampshire, seeks compensation for the familyís significant medical-related expenses, economic losses, and for Ericís pain and suffering.
 

Eric consumed a hamburger made from ground beef purchased at Stop & Shop at a family barbecue on September 4, 2005. He subsequently became ill with an E. coli infection, experiencing painful abdominal cramping, nausea, vomiting, and bloody diarrhea. Eric was seen in the emergency room at Concord Hospital twice, and was admitted to the hospital on his second visit. Twenty-four hours after being admitted, he was transferred by ambulance to Dartmouth-Hitchcock Medical Center (DHMC). Eric developed hemolytic uremic syndrome (HUS)*, a complication of E. coli O157:H7 infection, and spent 22 days in a pediatric intensive care unit at DHMC, undergoing several surgical procedures and eight rounds of kidney dialysis treatments after his kidneys shut down. Ericís medical bills to date total over $100,000.

ìWe filed this lawsuit after months of trying to discuss with Stop & Shop how to make matters right for Eric and his family,î said Denis Stearns, the Marler Clark partner who filed the lawsuit. ìMedical bills aside, the strain on the family was enormous. John, Christine, and their other children faced the possibility that Eric might not recover from his illness. John and Christine were forced to leave their two younger children with family members while they stayed with Eric at the hospital. And all of this was because of tainted meat.î
The City of Manchester Department of Health and the New Hampshire Department of Health and Human Services conducted an investigation into the cause of Ericís E. coli infection. The Stop & Shopís meat department was cited for unsafe meat-handling practices, a ìcritical violation,î and E. coli O157:H7 was found in uncooked hamburger patties made from ground beef purchased at Stop & Shop. Health officials concluded that the source of Ericís E. coli infection was contaminated ground beef purchased from Stop & Shop.
 

*Hemolytic Uremic Syndrome is a frightening illness that even in the best American medical facilities has a mortality rate of about 5%. About 50% of patients require dialysis due to kidney failure, 25% experience seizures, and 5% suffer from diabetes mellitus. The majority of HUS patients requires transfusion of blood products and develops complications common to the critically ill. Among survivors of HUS, about five percent will eventually develop end stage kidney disease, with the resultant need for dialysis or transplantation, and another five to ten percent experience neurological or pancreatic problems which significantly impair quality of life. See www.about-hus.com.
BACKGROUND: Marler Clark (www.marlerclark.com) has extensive experience representing victims of foodborne illnesses. William Marler represented Brianne Kiner in her $15.6 million settlement with Jack in the Box in 1993. In 1998, Marler Clark resolved Odwalla Juice E. coli outbreak cases for five families whose children developed HUS and were severely injured after consuming contaminated apple juice for a reported $12 million. The firm has litigated dozens of E. coli cases against supermarket chain stores, including Albertsonís, BJís Wholesale Club, Cub Foods, Price Chopper, and Supervalu. Marler Clark is working with David McGrath of Sheehan Phinney Bass & Green, PA, on the case.

Philippines Mangoes Get Green Light for USA Market; (July 25, 2006); Manila Standard Today:  By Othel V. Campos

The United States will finally allow the entry of fresh Philippine mangoes to Guam and Hawaii before the end of the year. For years, only mangoes from Guimaras were allowed entry to the US and its territories.

ìWe see the approval coming before yearend. That will include areas where mangoes are better grown except for Palawan,î said US department of agriculture trade office director Dennirs Voboril.  It took years before the Philippines was allowed to export mangoes from the quarantined confines of Guimaras Island in the Visayas due to pest threats.  The Philippines is the fifth-largest producer of mangoes in the world and the sixth among the top exporters of mango, accounting for 9 percent of the market.

Philippine mangoes are afflicted with the so-called mango pulp and seed weevil diseases, a sanitary and phytosanitary consideration among importing countries. But this did not prohibit other nations such as Japan, Korea, New Zealand, China, the European Union, Canada and Middle East from importing Philippine mangoes.

Mango exporters said USDAís concern about pulp weevil infestation was based on an old survey in province of Palawan.

The forthcoming approval, should it be served before the year ends as promised, will be another breakthrough for the agriculture sector which has been fighting for trade access for fresh fruits to different markets worldwide.

ìOnce the approval is issued this year, it will enable exporters to ship earlier than the scheduled 2007 effectivity of the revised US Federal Rule. Except for Palawan, other mango producing areas will be able to penetrate the Hawaii and Guam markets, and subsequently other US territories and mainland states,î said Voboril.

USDA will also release a $2-million grant next month to the Bureau of Plant Industry, which already started a study on how to enhance the export competitiveness of Philippine mangoes intended for export to the US.

The study will include evaluating the use of irradiation facility to treat mango fruit pests as well as a survey to determine the existence and prevalence of the mango pulp weevil and seed weevil diseases and measures to extend the shelf-life of fresh mangoes intended for shipment to the US mainland and its territories.

USDA specified that there should be measures on strengthening the capability of the Philippine quarantine office to ensure it complies with the USDA sanitary and phytosanitary standards.

Voboril said the irradiation method to treat mangoes was not necessarily a precondition to USDAís approval of exports although the US was previously pushing for the irradiation technology to replace the widely accepted international vapor heat treatment technology.

The U.S. Department of Agriculture is proposing to allow the importation of irradiated pineapples and other tropical fruits from Thailand -- products that could compete directly with Hawaii fruits for sales on the mainland and locally.

Besides pineapples, the proposal would allow the direct importation of lychees, rambutans, mangos, longans and mangosteens, which are grown in approved areas in Thailand and treated with irradiation to kill insects and other pests.

The proposed rule change was published yesterday in the Federal Register to seek public comment on the new rules.

Agriculture statistics show an estimated 212,000 tons of pineapples were grown in Hawaii last year with a value of $79.3 million. About half of the crop was sold as fresh pineapples, which command a higher wholesale price than fruit for processing.

The tropical specialty fruit industry is much smaller -- about $2.1 million in sales during 2004 -- but the industry has been a bright spot in the state's efforts to diversify agriculture.

Terri Gorman, director of corporate communications for Maui Land & Pineapple, said the company had not seen the proposed rule change yesterday and could not comment on how it might affect the local pineapple industry.

But tropical-fruit growers said they believe it will be difficult to compete with Thailand on price.

"Any place in the world can grow it cheaper than we can grow it here," said Leslie Hill, of the Wailea Agricultural Group, which raises and sells lychees, rambutans and other tropical fruit. In Thailand, Hill said, rambutans can sell for 5 cents a pound, versus $3 a pound in Hawaii.

"It (the impact of the rule change) could be dramatic. The whole state of Hawaii could be affected. We grow the same things (as Thailand)," said Susan Hamilton, a vice president of Hula Brothers farm and the Hawaii Tropical Fruit Cooperative.

The growers say Hawaii can still offer a better-quality product that can command a higher price.

"We've been able to compete against fruit coming up from Central America and Mexico," said Richard Johnson, of Onomea Orchards and the president of the Hawaii Tropical Fruit Growers Association.

But they say the USDA is favoring other countries over Hawaii.

Growers noted that the rule change proposes allowing mangosteens from Thailand to enter the United States with irradiation treatment, but USDA does not allow mangosteens from Hawaii to be shipped to the mainland using that treatment.

"The United States Department of Agriculture treats us with less respect, less funding than it does for foreign competitors," Hamilton said. "Are they going to see the same kind of inspections and governance that we do? Historically that doesn't necessarily hold true."

Lyle Wong, plant division administrator of the state Department of Agriculture, said the growers have a point, and the state has formally asked the USDA to allow mangosteens from Hawaii to be shipped to the mainland if the rule change for Thailand is approved.

In yesterday's filing the USDA said it is unlikely that the importation of fruit from Thailand will "substantially affect" local markets for pineapples and tropical fruit and that the rule change could benefit U.S. businesses that import fruit.

The USDA notes that imports of mangos and pineapples already far exceed the domestic production, and domestic production has remained relatively constant.

The agency believes allowing the Thai fruit into the United States will have more of an impact on other countries that export tropical fruit than on domestic growers.

But Hamilton said about 85 percent of her business involves shipping fruit to the mainland, mostly to Asian markets, and Thailand will likely be a direct competitor.

The fruit growers are unlikely to sue the USDA to stop the rule change should it be adopted, Johnson said. That is because some Hawaii growers use a similar irradiation process to kill pests before shipping fruit to the mainland.

In fact, the same process that makes it possible for Hawaii growers to ship fruit to the mainland is helping to create a global market for irradiated fruit, Wong said. He added that the Philippines has asked for permission to ship irradiated mangos to the United States, and other countries are also seeking exceptions.

"It's the beginning for more worldwide movement of tropical fruit products using irradiation," Wong said.

Tish Uyehara, the director of marketing for Armstrong Produce in Honolulu, said her company prefers to buy from local growers. But she added that local growers have to be competitive with quality, volume and price of their fruits.

"We are truly becoming a global market. I think everyone in the food business has to recognize that," Uyehara said.

Radiation-Killed Bacteria Induces Broad Immune Response in Mice: National Institutes of Health Press Release:

Vaccines made with bacteria killed by gamma irradiation, rather than by standard methods of heat or chemical inactivation, may be more effective, say researchers supported by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH). Vaccines made from gamma-irradiated bacteria also may not need to be kept cold; an advantage in settings where refrigerating vaccines is impractical or impossible. A report on the research appears in the current issue of the journal "Immunity".

In experiments with mice, scientists including Eyal Raz, M.D., Sandip Datta, M.D., and Joshua Fierer, M.D., of the University of California, San Diego, School of Medicine demonstrated that a vaccine made from irradiated "Listeria monocytogenes" bacteria, unlike a vaccine made from heat-killed bacteria, provides protection against challenge with live Listeria. The irradiated bacteria also stimulated a protective response from immune system cells called T cells. Previously, only vaccines made from live, weakened "Listeria" bacteria were believed capable of eliciting a T-cell response.

"This advance is potentially of great importance in meeting the challenge of creating vaccines that are safe, effective and simple to manufacture and transport," says NIH Director Elias A. Zerhouni, M.D.

Ideally, vaccines should stimulate a strong response not only from both arms of the adaptive immune system (antibodies and T cells), but also the body's innate immune system. However, traditional ways of making vaccines -- either by killing disease-causing agents with heat, chemicals or by weakening (attenuating) live pathogens -- have characteristic shortcomings. For example, heat- and chemical-killed vaccines, while safe and relatively easy to produce, generally produce a less broad immune response than live, attenuated vaccines. Conversely, it can be difficult to create live, attenuated vaccines that safely preserve the pathogen's ability to trigger strong innate and adaptive immune responses.

"By showing that whole, irradiated bacteria can form the basis of a vaccine that elicits a strong response from both arms of the adaptive immune system, Dr. Raz and his colleagues have opened the possibility of making a variety of bacterial vaccines that combine the best features of both killed-agent and live, attenuated vaccines," says NIAID Director Anthony S. Fauci, M.D.

Earlier research in Dr. Raz's laboratory had shown that irradiated probiotics (bacteria that are beneficial to health) retain the ability to trigger innate immune system responses via proteins called toll-like-receptors. Based on that observation, says Dr. Raz, "we hypothesized that a vaccine made from whole, irradiated bacteria would retain the properties needed to evoke a broad immune response and result in a superior vaccine compared with other methods of killing the pathogen."

The investigators inactivated "Listeria" with lethal doses of gamma radiation and then vaccinated a group of 10 mice twice with the irradiated bacteria. Another group of 10 mice received two inoculations with heat-killed "Listeria", while a third group of 10 received no vaccine. Twenty-eight days after the first vaccinations, all the mice were infected with a large dose of live "Listeria" (four times the amount required to kill 50 percent of infected unvaccinated animals). All the unvaccinated mice and all the mice vaccinated with heat-killed "Listeria" died, but 80 percent of the mice vaccinated with the irradiated bacteria survived. Further experiments showed that protection conferred by irradiated "Listeria" bacteria lasted for at least 12 months, indicating that the vaccine promoted the development of a "memory" T cell response.

Consistent with their earlier experiments with irradiated probiotics, Dr. Raz and his colleagues also found that irradiated "Listeria" retained the ability to stimulate innate immune responses via toll-like-receptor proteins. "Although completely inactivated by the radiation, and thus unable to cause illness, irradiated bacterial pathogens evidently retain characteristics that prompt the immune system to mount a full-fledged defense," says Dr. Datta, the study's lead author. "In this respect, irradiated pathogens more closely mimic the body's response to a live, attenuated vaccine."

Finally, the scientists found that mice could be protected by vaccination with irradiated "Listeria" that had been freeze-dried into a powder. This point is potentially of great practical importance, notes Dr. Raz. A serious drawback of live, attenuated vaccines is that they must be kept refrigerated at all times: if the "cold chain" is broken, the vaccine is liable to spoil and become useless. In countries with reliable electricity, maintaining the cold chain is rarely a problem. The same is not true in less developed countries. Vaccines made from whole, irradiated bacteria, freeze-dried into an easy-to-transport powder, could be reconstituted just before use, explains Dr. Raz, thereby eliminating the cold chain requirement.

It is also possible that a strategy based on irradiation-inactivated whole pathogens could rapidly yield vaccines against such bacterial diseases as typhoid, cholera, tuberculosis and other diseases of public health concern, such as intestinal parasites. This strategy might also be deployed in the event of epidemic outbreaks or against bioterrorist attacks, says Dr. Raz.

Top of Update