Why can't we test our way to absolute food safety?
12 Dec 2008
Science, Vol 322 [edited][iFSN]
Shaun Kennedy of the University of Minnesota writes that public attention to recent foodborne illness outbreaks raises an obvious question: Why aren’t contaminants found before they sicken consumers? Several recent examples—including Salmonella enterica serovar Saintpaul in produce, Escherchia coli O157:H7 in ground beef, Listeria monocytogenes in ready-to-eat meat, and melamine in infant formula—have led elected officials and consumer groups to call on the food industry and regulatory agencies to prevent contaminated foods from reaching the kitchen or restaurant. The problem is that no amount of testing can ensure that every food item is free from accidental or intentional contamination. However, protection strategies can be developed that combine low-cost detection methods with steps that mitigate hazardous outcomes.
Methods for detecting food contamination face several hurdles. Ideally, they should be specific—correctly identifying the contaminant—and sensitive, confirming the lack of contamination. Methods should be fast (giving results in minutes or hours), require minimal sample preparation before analysis, and be low in cost. However, these goals are often conflicting. The ability of detection strategies to mitigate harm to public health is further challenged by unanticipated combinations of foods and contamination agents, as well as the threat of intentional contamination.
The single largest challenge is often overlooked: deciding when to test, and for what agents. Detection strategies can be categorized as “detect to prevent” (confirmation that food is not contaminated before it leaves the farm or facility); “detect to protect” (detection before food items become available for consumption); and “detect to recover/detect to regret” [limiting the scope of an outbreak, attributing its origin, or both (1, 2)]. If the goal is “detect to prevent/protect,” sampling strategies that incorporate food supply-chain characteristics become paramount, but also complicated.
The story goes on to conclude that against this backdrop, the most rational path forward is the selective use of low-cost, highly sensitive and specific assays for food safety along with even more selective use of low-cost, less sensitive but very low false-positive rate assays for food defense. Points of detection must also be selected with a detailed understanding of the supply chain to ensure that public health is protected in an economically sustainable way. Given that the “tricorder” of Star Trek lore is still a scientific fantasy, pathogen detection alone will not eliminate the potential for contaminated food reaching the consumer. Detection strategies must be combined with multiple prevention efforts to best protect consumers of the global food system.

Bird flu makes mallards thin, study finds
3 Dec 2008 [edited] [Promed]
Thomson Reuters Foundation AlertNet
Avian flu viruses make mallard ducks thinner than other ducks, a finding that implies they do not spread the germs over long distances, researchers reported on Tuesday [2 Dec 2008]. Their tests of thousands of ducks migrating through Sweden showed the viruses do affect the birds, contrary to conventional wisdom that the pathogens have no effect on them. And, to their surprise, they found the birds only "shed", or release, virus for a few days, the researchers reported in the Proceedings of the Royal Society B: Biological Sciences.
"Mallard ducks are a main reservoir for low-pathogenic avian influenza [LPAI] virus in nature, yet surprisingly little is known about how infection affects these birds," Jonas Waldenstrom of Sweden's Kalmar University, Albert Osterhaus of Erasmus Medical Center in Rotterdam and colleagues wrote.
A reservoir is a species that hosts a virus without becoming ill, and thus serves to spread it. Avian flu viruses have most often been found in migratory waterfowl, especially mallard ducks.
"We analyzed 10,000 samples from migratory mallards in Sweden for presence of influenza virus and were able to demonstrate that infected birds were leaner than uninfected birds, and that weight loss was related to the amount of virus shed in their feces," Waldenstrom's team added. "Although many mallard populations are migratory, the short virus shedding times (often less than a week) imply that individual birds are not long-distance dispersers of the virus on a continental scale."
There are hundreds of kinds of bird flu, and evidence suggests that human forms of influenza originate in birds. Low-pathogenic avian influenza strains generally have little effect, although the highly pathogenic forms can wipe out flocks in a matter of days. Highly pathogenic H5N1 avian influenza [HPAI] is currently affecting flocks in Asia, parts of Europe, and Africa and experts fear it may mutate into a form that humans can catch and transmit easily. If it does, it could kill millions. Even in its current hard-to-catch form, H5N1 has infected 387 people and killed 245 since 2003. Researchers do not know precisely how it spreads, although migrating birds are prime suspects, as is the poultry trade.
Waldenstrom's team found that infection did not affect how fast or far the birds migrated. On average, the ducks were infected 8 days and spread the virus for just 3 of them in their droppings. "The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales," they wrote. But they may stay longer in one place when they are infected -- something that needs to be studied, they added.

Humans prompted new paths for parasites
25 Nov 2008
Agricultural Research Service, USDA - Ann Perry, ARS News Service [edited] [iFSN]
Agricultural Research Service (ARS) scientists are tracking how the dissemination of the parasite Trichinella spiralis throughout Europe, North Africa and the Americas was facilitated by human travel and the transportation of animals. T. spiralis lurks in the muscle tissue of a wide range of mammals and can infect humans who consume undercooked meat contaminated with the parasite. It is no longer a major threat to the U.S. food supply, but it does persist in some European countries. Ben Rosenthal, Dante Zarlenga and Detiger Dunams work at the ARS Animal Parasitic Diseases Laboratory in Beltsville, Md. They used Trichinella DNA collected from 28 countries on four continents to evaluate potential links between parasite hosts, geographic distribution and species diversity. Over time, the genetic traits of a pathogen may shift as the pathogen expands beyond its original range and becomes isolated. Geographic barriers prevent contact between the new populations, and these barriers support the development and maintenance of unique genetic mutations within each group. These mutations, in turn, can be used to trace the links between individuals in each population. They can also be compared with populations that have dispersed to other areas. Although T. spiralis is believed to be at least 20 million years old, the scientists were surprised to find that parasite samples from Europe, North Africa and the Americas had remarkably uniform DNAs. In fact, statistical analyses grouped all 44 samples from all evaluated regions into a single "Western" group of T. spiralis , due to the high degree of genetic similarity. This evidence suggests that the T. spiralis found in Europe first evolved after the domestication of swine. Settlers on their way to the New World and elsewhere traveled with swine for food, and some of these pigs were infected with T. spiralis. The team concluded that human travel was the primary source of disseminating T. spiralis throughout the New World. They also believe that these migration patterns explain the limited range of genetic diversity observed in the European, North African and the American isolates of T. spiralis.

Real burden and potential risks from foodborne infections: the value of multi-jurisdictional collaborations
01 Nov 2008
Trends in Food Science & Technology (Volume 19, Supplement 1, Pages S14-S21)
Robert V. Tauxe [edited][iFSN]
sciencedirect.com
The burden of foodborne infections on the public health is substantial. Many different microbes can contaminate foods and cause illness in the consumer. New and emerging problems are identified with regularity, as a result of microbial change, of changing patterns of production and trade, and the complex ecologies in which we produce and process the foods we eat. In the United States, the zoonotic pathogens Salmonella , Campylobacte r, Shiga toxin-producing Escherichia coli (such as E. coli O157:H7), Listeria and Toxoplasma are major challenges. Public health surveillance is vital to estimate the burden, to detect outbreaks, and to track trends in the illness as interventions take place. Cases reported to public health authorities represent only a small fraction of those that occur, but if that fraction is known, the total number of cases can be estimated. Most cases are sporadic, occurring outside of recognized outbreaks. With systematic molecular methods for surveillance, large and dispersed outbreaks can be identified. Investigation of outbreaks of illnesses can detect new pathogens, establish new food vehicles, and identify likely points of contamination. The results of surveillance, of research based on sporadic cases, and of outbreak investigations can guide the important multi-disciplinary research in food science, veterinary and ecological sectors that are critical to improving prevention upstream from the consumer. Because microbes travel freely across boundaries, this increasingly requires a transnational approach. We can anticipate more unexpected challenges, even as current challenges are controlled. Robust, stable and flexible public health platforms for surveillance, for investigation, and for supporting interdisciplinary research that improves prevention are important to sustained progress in the field of food safety.

Outbreaks where food workers have been implicated in the spread of foodborne disease. Infective doses and pathogen carriage
01 Nov 2008
Journal of Food Protection, Volume 71, Number 11, pp. 2339-2373(35) [edited][iFSN]
Todd, Ewen C.D.1; Greig, Judy D.2; Bartleson, Charles A.3; Michaels, Barry S.4
In this article, the fourth in a series reviewing the role of food workers in foodborne outbreaks, background information on the presence of enteric pathogens in the community, the numbers of organisms required to initiate an infection, and the length of carriage are presented. Although workers have been implicated in outbreaks, they were not always aware of their infections, either because they were in the prodromic phase before symptoms began or because they were asymptomatic carriers. Pathogens of fecal, nose or throat, and skin origin are most likely to be transmitted by the hands, highlighting the need for effective hand hygiene and other barriers to pathogen contamination, such as no bare hand contact with ready-to-eat food. The pathogens most likely to be transmitted by food workers are norovirus, hepatitis A virus, Salmonella , Shigella, and Staphylococcus aureus . However, other pathogens have been implicated in worker-associated outbreaks or have the potential to be implicated. In this study, the likelihood of pathogen involvement in foodborne outbreaks where infected workers have been implicated was examined, based on infectious dose, carriage rate in the community, duration of illness, and length of pathogen excretion. Infectious dose estimates are based on volunteer studies (mostly early experiments) or data from outbreaks. Although there is considerable uncertainty associated with these data, some pathogens appear to be able to infect at doses as low as 1 to 100 units, including viruses, parasites, and some bacteria. Lengthy postsymptomatic shedding periods and excretion by asymptomatic individuals of many enteric pathogens is an important issue for the hygienic management of food workers.

Consumers losing patience with recalls: survey
31 Oct 2008
Progressive Grocer [edited][iFSN]
Consumers’ buying habits have undergone dramatic changes, and could end up costing companies millions, when product safety and quality issues are at stake, according to a study released this week by Deloitte, LLP.
Over half of respondents (58 percent) who heard about product safety and/or quality problems altered their buying habits, according to the report, “Food and Product Safety and Its Effect on Consumer Buying Habits.” These consumers refrained from buying such products for an average of over nine months, increasing the likelihood that they would stop buying the product or brand altogether.
“Our research shows that consumers are becoming less tolerant of recalls, with more than 50 percent changing their product choices,” noted Pat Conroy Deloitte, LLP’s vice chairman and consumer products practice leader. “As these consumers continue to buy different products, product manufacturers can expect lower sales and run the risk of damage to their brands.”
The survey focused on key issues in the toy, consumer electronics, fresh food, and packaged food/beverage categories.
Of these categories, changes in buying habits were highest for fresh food and packaged food/beverages. About half (49 percent) of those surveyed said they were extremely concerned about product safety, with the greatest concerns coming from women (53 percent) and consumers age 55 and older (56 percent). Fifty-four percent of respondents said they were more concerned about the safety of fresh food products than they were a year ago.
Approximately two-thirds of respondents (65 percent) were extremely concerned about the safety of products made outside the United States, with the greatest worry coming from older consumers.
About three-quarters of the overall respondents (73 percent) said they extremely concerned about the safety of products made in China, with half having the same doubts about products hailing from Southeast Asia and Mexico.
Further, consumers polled said they wanted more information about food products’ safety to be listed on packaging (86 percent) and on company Web sites (81 percent), and as well as provided by the government (81 percent). Sixty-seven percent said that food product labels with country-of-origin labeling, certification of product testing and certification of quality testing would figure significantly in their buying decisions.
According to the research, some key factors driving the extent of a product recall’s impact on a company’s business include the extent of the company’s product diversification, if the recall is specifically for a branded product, the strength of the company’s brand when the incident occurred, and the company’s response.
“Companies are meeting consumers’ concerns by upgrading or expanding safety procedures, including stricter safety standards, testing, and third-party audits, and government intervention is driving change,” noted Conroy. “The recent granting of the Consumer Product Safety Commission to initiate product recalls and monitor ingredient levels such as lead allowed in toys and other children’s products is a very timely and relevant example of changes being made all with consumer safety and peace of mind at the top of the agenda.”
The survey, which was commissioned by Deloitte and conducted online by an independent research company on Sept. 3, 2008, polled a nationally representative sample of 1,004 adult consumers, with a margin of error of +/- 3.1 percentage points at the 95 percent confidence level.


Phages to control L. monocytogenes in food and animals win patent
27 Oct 2008
Food Innovation Weekly [iFSN]
Exponential Biotherapies, Inc. (Port Washington, NY) last week won U.S. patent 7,438,901 for a class of virulent bacteriophages that reduce the presence of Listeria monocytogenes in food and food processing equipment and, in some cases, prevent their growth altogether.
“One specific example of a virulent Listeria monocytogenes phage, is a phage designated P100, recently discovered by one of the present inventors,” the company said in the patent documents. “The present invention also relates to an endolysin produced by P100 and the use of the endolysin for reducing the amount of Listeria monocytogenes in foods products as well as on processing equipment and other sites in food industry facilities, and in or on animals infected with Listeria monocytogenes and to methods that will enable additional phage that have lytic properties to be developed and/or isolated.”
The company adds: “In the present invention, a recombinant DNA vector is prepared using virulent phage P100 which is specific for Listeria monocytogenes . The vector includes a genetic system comprising DNA which encodes the expression of one or more detectable proteins which are not a gene product of Listeria monocytogenes . The DNA vector infects the bacteria of the genus Listeria and transfers the genetic system to the bacteria. The detectable proteins are expressed by the bacteria and the detection of the detectable proteins indicates the presence of bacteria of the genus Listeria .
“An endolysin derived from P100 is used to reduce the counts of Listeria monocytogenes and/or to prevent their growth in the first place, in foods products (including but not limited to the dairy industry) as well as on processing equipment and other sites in food industry facilities, and as a therapeutic agent for treating animals infected with Listeria monocytogenes . Endolysins from Listeria phages have high substrate specificity and almost exclusively lyse Listeria cells.
“The present invention is directed to the use of a class of Listeria monocytogenes phages which are particularly suitable for bacterial control methods and for the detection of Listeria monocytogenes . The phage are preferably from the Myoviridae family and are virulent against Listeria monocytogenes strains of serovar 1/2. In addition, the present invention isolates virulent mutants of temperate strains and uses those specific mutants in the control of bacterial contamination of foodstuffs and of food processing plants.”

New method for detecting Listeria
27 Oct 2008
Food Innovation Weekly [iFSN]
Kraft Foods Holdings Inc. (Northfield, IL) was awarded patent last week for a new Listeria rapid-detection method using isolated nucleic acids in PCR tests.
Other detection methods “are based mainly on targeting genes that play a role in the pathogenicity of L. monocytogenes ,” Kraft wrote in the patent documents. “It is known that some of these genes are located on the chromosome next to each other in a virulence gene cluster. Since the listeriolysin gene (hlyA) has been recognized as a necessary gene for the pathogenicity of L. monocytogenes , most of the genotypic detection methods are based on this gene sequence.
“Although strains of Listeria monocytogenes are the only pathogens to humans, testing for this specific group would be limiting in an effort to identify potential growth habitats for them in food manufacturing facilities. Thus, testing to detect all Listeria species is useful in the identification of harborage site. This identification is necessary to allow for through sanitation and the subsequent elimination of Listeria .”
Kraft added that another drawback to current detection methods is that they can pick up similar genes that aren’t actually Listeria , making the tests less accurate. Thus, “there is a need for oligonucleotides that can be utilized for diagnostic purposes to detect low levels of the Listeria genus. These oligonucleotides can be applied to the many different PCR amplification techniques to provide a quick, sensitive and specific test. The sensitivity and specificity of such a test will make it possible to reduce the incubation time of a culture enrichment step thereby decreasing the overall time needed to get a test result.”
The new patent covers nucleic acid sequences that can be used to facilitate such rapid detection. “Genes have been identified which are unique to the genus of Listeria and provide targets for rapid nucleic acid assays effective for identifying the presence of Listeria ,” Kraft said. “The assays provided can detect as few as 10 copies of said target gene sequences and can provide results within an hour of the start of a polymerase chain reaction. The identified nucleic acid sequence can be incorporated in to a real time quantitative polymerase chain reaction. Each of the oligonucleotide sequences can also be used as probes for hybridization to Listeria DNA.
“Two gene targets rnpB and rfn are identified for the detection of the Listeria genus. Oligonucleotides targeting these genes are provided that can be utilized in the rapid detection of the Listeria genus from food, environmental or clinical samples. An important feature of these olignucleotides is their specificity and sensitivity. Usage of these oligonucletides in the polymerase chain reaction can allow for the detection of very low numbers of Listeria cells. Their high specificity also allows for the use of non-selective culture enrichment media for the accelerated growth of Listeria cells that can subsequently reduce the amount of culture enrichment time necessary to reach detectable concentrations.”

An ecological analysis of sociodemographic factors associated with the incidence of salmonellosis, shigellosis, and E. coli O157:H7 infections in US counties
24 Oct 2008
Journal of Epidemiology and Infection [edited] [iFSN]
M. Chang, S. L. Groseclose, A. A. Zaidi and C. R. Braden
Identifying county-level sociodemographic and economic factors associated with the incidence of enteric disease may provide new insights concerning the dynamics of community transmission of these diseases as well as opportunities for prevention. We used data from the National Notifiable Diseases Surveillance System, the U.S. Census Bureau, and the Health Resources and Services Administration to conduct an ecological analysis of 26 sociodemographic and economic factors associated with the incidence of salmonellosis, shigellosis, and E. coli O157:H7 infections in US counties for the period 1993 to 2002. Our study indicates that race, ethnicity, place of residence, age, educational attainment, and poverty may affect the risk of acquiring one of these enteric bacterial diseases. The lack of specificity of information regarding Salmonellae and shigellae serotypes may have led to less specific associations between community-level determinants and reported incidence of those diseases. Future ecological analyses should use serotype-specific data on incidence, which may be available from laboratory-based surveillance systems.

Food safety and tourism.
21 Oct 2008
4Hoteliers - Dr. Peter Tarlow, Ph.D. [edited][iFSN]
Dr. Peter E. Tarlow writes that the recent food scares, such as the recent outbreak of contaminated milk in China, once again serve to underline the important interconnection between tourism and food safety.
While tourism experts are not expected to be specialists in food safety they do need to be aware that food safety issues are more than merely making sure that the mayonnaise is refrigerated. The US Congressional Research Service for the Library of Congress published a major paper on Agro-terrorism.
The CRS defined 'agro-terrorism' as a subset of bio-terrorism in which diseases are introduced into the food supply for the expressed purpose of creating mass fear, physical harm or death and/or economic loss. In today's global economy tourism entities import foods from around the world, which means that an agro-terrorism attack on one continent can destroy a tourism industry on another continent.
In fact, food safety and tourism security have been linked for many decades. Even superficial study of the food industry reveals that it vulnerable on almost all levels. From processing until delivery to the table, food for human and animal consumption goes through a number of hands, machines and processes.
Tracing where food may have been contaminated is difficult and when we must distinguish between accidental food contamination and terrorist contamination geared toward a political purpose the task becomes monumental. Restaurants are vulnerable for still another reason: they are icons of their society or of another society. For example, it is almost impossible to separate a pizzeria from Italian culture or a croissant from French culture.
Restaurants and other eating establishments can be targeted for a number of reasons here are just a few:
* Most restaurant owners do not know their patrons, thus as public places, restaurants provide easy access and exits
* Most restaurants in tourism areas have no idea where their clients are after they have left their premises. This lack of information means that it is difficult to track down what food poisoning
* Restaurants rarely keep records as to where participants live or how many came in a party
* Restaurants sell good times and therefore vigilance is low
* Most restaurants can easily be penetrated. Often back/side doors are left open and waiters and waitresses, working for tips, may not challenge a customer out of fear of losing income.
* Tourism depends on a safe and reliable food supply. Tourists and visitors cannot often go to local markets to buy food supplies and usually need to depend on restaurants or other public places to purchase food.

New method may rapidly detect significant foodborne pathogen
16 Oct 2008
Huliq News
American Society for Microbiology [edited][iFSN]
Researchers from Sweden and Finland have developed a rapid and specific method that may detect the bacterium Yersinia enterocolitica , a common cause of gastric illness, in food. They report their findings in the October 2008 issue of the journal Applied and Environmental Microbiology. Y. enterocolitica is the causative agent of yersiniosis, an internal infection resulting in diarrhea, fever, abdominal pain, and vomiting. Predominantly considered a food-borne pathogen, most cases sporadically occur worldwide and the source of infection is often unknown. Pigs are believed to be a main reservoir for Y. enterocolitica with pork being the most likely vehicle of transmission to humans. The ability of Y. enterocolitica to multiply in foods at low temperatures as well as in vacuum-packed containment is cause for major food safety concern and current detection methods available are time consuming and inefficient.
In the study researchers developed and evaluated a TaqMan probe-based real-time PCR method for detecting Y. enterocolitica in food in one to two days. Following overnight synthetic enrichment of samples of milk, minced beef, cold-smoked sausage, fish and carrots with Y. enterocolitica , results of the TaqMan PCR test showed high levels of sensitivity, robustness, precision and efficiency in detecting the bacterium. "A rapid and specific real-time PCR method for the detection of pathogenic Y. enterocolitica bacteria in food, as presented here, provides a superior alternative to the currently available detection methods and makes it possible to identify the foods at risk for Y. enterocolitica contamination," say the researchers.


Application of atomic force microscopy on rapid determination of microorganisms for food safety
09 Oct 2008
Journal of Food Science, Volume 73 Issue 8, Pages N44 - 50 [edited][iFSN]
H. Yang and Y. Wang
Rapid detection and quantification of microorganisms is important for food quality, safety, and security. In this field, nanotechnology appears to be promising in its ability to characterize an individual microorganism and detect heterogeneous distribution of microbes in food samples. In this study, atomic force microscopy (AFM), a nanotechnology tool, was used to investigate Escherichia coli ( E. coli ) qualitatively and quantitatively. E. coli strains B and K12 were used as surrogates to represent pathogenic strains, such as E. coli O157: H7. The results from AFM were compared with those from scanning/transmission electron microscopy (SEM/TEM). The qualitative determination was obtained using morphology and characteristic parameters from AFM images, and the quantitative determination was obtained by calculating the microorganisms in AFM images. The results show that AFM provides a new approach for rapid determination of microorganisms for food safety.

Making it work: The application of time as a public health control in the field
26 Sep 2008
Journal of Environmental Health, Sept. 2008 [edited][iFSN]
Nyali Hislop, M.Sc., CPHI(C)
Time as a public health control (TPHC) is increasingly being recognized as a viable alternative to temperature control for potentially hazardous foods in the developed world. This is reflected by recent changes to food regulations and other pertinent health legislation in both Canada and abroad. Considerable ambiguity remains, however, as to when and how TPHC should be applied at the field level. The author reviewed pertinent legislation, regional standards, and guidelines in various jurisdictions. The author did not identify standardized methods for having health departments receive applications from food vendors, for evaluating such applications for approval or rejection once received, or for monitoring food products subsequent to such an approval. A 4-step process was then designed to help ensure a standardized application of TPHC principles at the field level. Applications, representing a variety of potentially hazardous food products from both ethnic and North American cuisines, were reviewed and processed according to stated criteria. A structured format for the application, approval, monitoring, and evaluation of potentially hazardous ready-to-eat foods by management and field personnel helps improve consistency in the application of TPHC principles, demonstrate due diligence (for environmental public health departments), and relieve district environmental health officers (EHOs) from the pressures of having sole responsibility over the approval process.

Bisphenol A exposure may pose disease risk
17 Sep 2008
Nature [edited][iFSN]
High levels of bisphenol A, a chemical found in some food and drinks containers, may be associated with an increased risk of cardiovascular disease and diabetes. An epidemiological analysis of 1,455 adults in the United States, published this week (I. A. Lang et al. J. Am. Med. Assoc. 300, 1303–1310; 2008), is the first to find a link between bisphenol A and disease in humans. The results are likely to fuel further debate over whether the chemical should be banned, but the authors caution that the study must first be replicated. Earlier this year, the US National Toxicology Program expressed "some concern" about the possible impact of the compound on fetuses, infants and children. In a draft report released in August, the US Food and Drug Administration stated that "food contact" products containing bisphenol A are safe. The agency has said it will continue to review the compound as more data become available.

Low acrylamide french fries and potato chips
15 Sep 2008
ISB News Report - Caius M Rommens [edited][iFSN]
Some of our most popular processed foods contain small amounts of toxic acrylamide. Currently available methods that lower the accumulation of this reactive compound have a negative effect on sensory characteristics and/or are not broadly applicable. Realizing their limited options, several food companies have committed to substantially reducing the acrylamide levels in fried and baked potato products over the next three years. A novel method that could be applied to produce the desired low-acrylamide foods was recently published in Plant Biotechnology Journal. According to this method, potato plants are transformed with an all-native silencing construct that targets two asparagine synthetase genes. The resulting plants produce tubers with very low levels of the acrylamide precursor asparagine. French fries and potato chips from these "intragenic" plants contain up to 20-fold lower levels of acrylamide than their untransformed counterparts.

Salmonella attachment to vegetables
05 Sep 2008
American Society for Microbiology - Jeri D. Barak, Anita Liang, and Koh-Eun Narm [edited][iFSN]
This article reports differential contamination among agricultural seedlings by Salmonella enterica via soil. Members of the family Brassicaceae had a higher incidence of outbreak than carrot, lettuce, and tomato. Once they were contaminated, phyllosphere populations were similar, except for tomato. Contamination differences exist among tomato cultivars.

United States - Scientists use remote satellite imaging to predict outbreaks of infectious disease
02 Sep 2008
Wiley-Blackwell - Lucy Mansfield
The USA has established a way to predict outbreaks of cholera, making it easier to control. This finding could provide a model to predict and potentially control outbreaks of other important infectious diseases. Cholera is a serious, ancient water-borne infectious disease, which is an unpredictable and severe problem for developing countries.
The bacterium that causes cholera, Vibrio cholerae , has a known association with a crustacean (called a copepod) which lives on zooplankton, a type of plankton. Cholera outbreaks have been linked with environmental factors, including sea surface temperature, ocean height, and biomass (this is estimated by measuring chlorophyll produced by plankton). Professor Rita R. Colwell and her team at the University of Maryland, College Park, have used remote satellite imaging to track this climatologically important information and the data collected now can be used to predict outbreaks of cholera before they occur.

Mathematically assessing the consequences of food terrorism scenarios
01 Sep 2008
Journal of Food Science Volume 73 Issue 7 - Y. Liu 1 and L.M. Wein 1 [edited][iFSN]
This paper derives mathematical expressions for the mean number of casualties resulting from a deliberate release of a biological or chemical agent into a food supply chain. The analysis first computes the amount of contaminated food as a function of the network topology and vessel sizes in the food processing plant. A probabilistic analysis, in which each potential consumer of contaminated food has his own random purchase time, infectious dose, and incubation period, determines the number of people who consume enough tainted food to get infected or poisoned before the attack is detected and food consumption is halted. These simple formulas can be used by the U.S. government and the food industry to develop a rough-cut prioritization of the threats from food terrorism, which would be a 1st step toward the allocation of appropriate prevention and mitigation resources

All blood, No stool: enterohemorrhagic Escherichia coli O157:H7 infection.
24 Aug 2008
National Center for Biotechnology Information - Yoon JW, Hovde CJ [edited][iFSN]
Enterohemorrhagic Escherichia coli serotype O157:H7 is a pathotype of diarrheagenic E. coli that produces one or more Shiga toxins, forms a characteristic histopathology described as attaching and effacing lesions, and possesses the large virulence plasmid pO157. The bacterium is recognized worldwide, especially in developed countries, as an emerging foodborne bacterial pathogen, which causes disease in humans and in some animals. Healthy cattle are the principal and natural reservoir of E. coli O157:H7, and most disease outbreaks are, therefore, due to consumption of fecally contaminated bovine foods or dairy products. In this review, we provide a general overview of E. coli O157:H7 infection, especially focusing on the bacterial characteristics rather than on the host responses during infection.

Methods and tools for comparative genomics of foodborne pathogens
24 Aug 2008
National Center for Biotechnology Information - Bhagwat AA, Bhagwat M [edited] [iFSN]
A comparison of genome sequences and of encoded proteins with the database of existing annotated sequences is a useful approach to understand the information at the genome level. Here we demonstrate the utility of several DNA and protein sequence comparison tools to interpret the information obtained from several genome projects. Comparisons are presented between closely related strains of Escherichia coli commensal isolates, different isolates of O157:H7, and Shigella spp. It is expected that comparative genome analysis will generate a wealth of data to compare pathogenic isolates with varying levels of pathogenicity, which in turn may reveal mechanisms by which the pathogen may adapt to a particular nutrient supply in certain foods. These genome sequence analysis tools will strengthen foodborne pathogen surveillance and subsequent risk assessment to enhance the safety of the food supply.

United States - Rapid test for pathogens developed by K-State researchers could be used to detect diseases used by bioterrorists
21 Aug 2008
K-State Media -Katie Mayes
Dangerous disease often spreads faster than it takes to diagnose it in the lab. To remedy that, researchers at Kansas State University have developed a test to bring that time from days down to hours. Two researchers in the department of diagnostic medicine and pathobiology use a device called a DNA spotted microarray to seek out the specific genetic markers that set one pathogen apart from another and determine antibiotic resistance. Traditionally, it takes days and multiple lab workers to screen a sample of soil, water or feces for just one pathogen. Additional time is then needed to look for resistance to antibiotics. The new test developed at K-State simultaneously looks for multiple diseases and antibiotic resistance, reducing the time it takes from sampling to diagnosis to about 24 hours. The test's efficiencies also translate into lower cost, Narayanan said. Should the U.S. ever be attacked with biological weapons, Narayanan said the new test also will help in quickly identifying all of the bacterial pathogens used. Also, such pathogens would likely be engineered for resistance to common drug treatment and the new test would determine such resistance rapidly, Narayanan said.

World's farmers turn to raw sewage for irrigation
18 Aug 2008
New Scientist - Fred Pearce [edited] [iFSN]
As cities and industries suck up ever more of the world’s scarce water resources, agriculture is destined to rely increasingly on recycling the contents of urban sewers, according to a new international study of “wastewater agriculture”. According to this story, the good news – for farmers at least – is that the irrigation water from sewers comes with free fertiliser in the form of the nitrates and phosphates bound up in human faeces. The bad news is that this coprological cornucopia is filling vegetables sold in city markets with heavy metals, pathogenic bacteria and worms. An estimated one fifth of the world’s food is growing in urban areas, with perishables like vegetables to the fore. But a 50-city study by the International Water Management Institute (IWMI) – a World Bank-backed research agency based in Sri Lanka – finds that often the only source of the essential irrigation water to grow many of those crops is city sewage. Half of urban fields are irrigated with sewage, suggesting that a tenth of the world’s food is already grown this way: “This figure is bound to increase as growing cities coincide with escalating food shortages to create a squeeze on agricultural water supply.” Theoretically, irrigating food crops with untreated wastewater is banned in many countries, one reason why there is virtually no research on the practice. But “while it may be theoretically forbidden, it is unofficially tolerated”, says the report’s authors, who found that city authorities in Faisalabad in Pakistan auction untreated sewage to farmers during droughts. Some countries, including Israel, Mexico and Tunisia, treat sewage before delivering it to farmers, which removes bacteria and lumps, at least. But this is rare. In the Ghanaian capital Accra, 200,000 people buy vegetables grown on urban fields irrigated with tanker loads of wastewater that is untreated because the city’s sewage treatment works long since ceased to function. “I am worried about the toxins, especially heavy metals, accumulating in foods like root crops," says the IWMI’s director. "But often there is simply no other water. In many ways it is a great use of the waste and the nutrients it contains.” He says the best answer is not to ban the practice, but to improve it. “Even without expensive infrastructure, common sense measures can make wastewater irrigation safer.” Storing the wastewater in ponds allows solids to settle out, including the eggs of intestinal worms. And farmers should wash vegetables in clean water before selling them to markets.

Detection of infectious prions in urine
12 Aug 2008
FEBS Letters online [edited] [Promed]
By Gonzalez-Romero D, Barria MA, Leon P, Morales R, Soto C. At The George and Cynthia Mitchell Center for Neurodegenerative diseases, Departments of Neurology, Neuroscience and Cell Biology and Biochemistry and Molecular Biology, University of Texas Medical Branch,
Abstract
Prions are the infectious agents responsible for prion diseases, which appear to be composed exclusively of the misfolded prion protein (PrP(Sc)). The mechanism of prion transmission is unknown. In this study, we attempted to detect prions in urine of experimentally infected animals [hamster]. PrP(Sc) was detected in approximately 80 percent of the animals studied, whereas no false positives were observed among the control animals. Semi-quantitative calculations suggest that PrP(Sc) concentration in urine is around 10-fold lower than in blood. Interestingly, PrP(Sc) present in urine maintains its infectious properties. Our data indicate that low quantities of infectious prions are excreted in the urine. These findings suggest that urine is a possible source of prion transmis sion.

Sesame seed extract and konjac gum may help ward off Salmonella and E. coli
05 Aug 2008
Society of Chemical Industry - Meral Nugent [edited] [iFSN]
A new study in SCI’s Journal of the Science of Food and Agriculture shows that konjac gum and sesame seed extract may offer protection against different strains of E. coli and Salmonella bacteria. The study by Dr Petra Becker et al from Wageningen University and Research Centre, the Netherlands, shows that these foodstuffs act as binders for E. coli and Salmonella bacteria. The bacteria attach themselves to the fibrous foods instead of the gut cells of the host. Becker says that eating a diet full of these foodstuffs may offer protection from gastro-intestinal infections or reduce the severity of symptoms caused by E. coli or Salmonella . Other foods that were shown to have a beneficial effect included yeast, tomato, and pumpkin.

Hand hygiene in the food industry: Resolving an enigma?
31 July 2008
Food Protection Trends, Vol. 28, No. 8, Pages 568–584
HansRediers, MarijkeClaes, RitaKinnerk, LucPeeters and KrisA. Willems
Much experimental evidence points to poor hand hygiene as a likely major contributor to the occurrence of foodborne illnesses. Microorganisms are easily transferred from hands to other surfaces or vice versa, by cross contamination. Cross contamination is therefore an important contamination source of foodborne illness bacteria. In this review, we focused on the most important techniques used to minimize the risk of cross contamination by hands, including washing and disinfecting of hands, and the use of gloves. The efficacy as well as the inherent advantages and disadvantages of each technique are thoroughly discussed. Additional measures that can be taken to minimize the risk of contamination are also referred to. Finally, the legal requirements and the recommendations of relevant voluntary quality systems, such as British Retail Consortium (BRC), International Food Standard (IFS), and ISO 22000, concerning hand hygiene are summarized. With the information provided herein, a well-informed decision can be made to select the appropriate techniques to use in specific circumstances or environments.

'Green' potato health risk can be eliminated by cutting away affected area
25 July 2008
Society of Chemical Industry - Meral Nugent [edited] [iFSN]
Potatoes that have turned 'green' can potentially contain a naturally occurring toxin called Glycoalkaloids (GA) and pose a risk to public health according to a review paper published in the latest online issue of SCI's Journal of the Science of Food and Agriculture (JSFA). However, the good news is that cutting away the 'green' affected area is enough to eliminate most of the GAs to reduce the risk. The paper also suggests that the levels of GA in potatoes can be controlled effectively by adopting appropriate pre-harvest and post-harvest practices – and therefore farmers and producers can do much to reduce the public risks of GAs. Some measures include keeping tubers well covered with soil during growth, allowing them to mature before harvesting, avoiding harvest at very high temperatures and minimising exposure to light.
GAs are a naturally occurring toxic substance in potatoes that have antimicrobial, insecticidal and fungicidal properties which probably evolved as a protective mechanism against invasion by foreign bodies to protect the plant against pests and disease. However, they can be toxic to humans and can cause serious illness at concentrations of >280 mg kg-1 f.w.
Symptoms generally occur after 8-12 hours after ingestion and can include gastrointestinal disturbances and neurological disorders. Mild symptoms can include headaches, dizziness, abdominal pain, nausea, vomiting and diarrhoea. Other symptoms can include restlessness, drowsiness and mental confusion, trembling and hallucination but because the symptoms are common to a whole host of other ailments, mistaken diagnoses can occur.

Risk profiles of pork and poultry meat and risk ratings of various pathogen/product combinations
15 July 2008
International Journal of Food Microbiolgy (Volume 126, Issues 1-2, Pages 1-262)
M. Mataragasa, P.N. Skandamisa and E.H. Drosinos Risk profiles of pork and poultry meat were carried out using an Excel-based software program, Risk Ranger. It is a semi-quantitative risk estimator answering various questions relating to the probability of exposure to a hazard, susceptibility of the population of interest, severity of the illness caused by the hazard if present and probability of food containing an infectious dose. Therefore, qualitative and quantitative inputs were used to estimate and rank the risk of various hazards/food combinations. Risk scores provided by the tool were characterized as low, medium and high. Also, health risk was estimated separately, where needed, for low and high risk populations. Low risk scores were obtained for Salmonella spp., Listeria monocytogenes and enterohaemorrhagic Escherichia coli (EHEC) for low risk population. High risk scores were obtained for hepatitis E virus (HEV) in raw pork products (both low and high risk populations). Moderate risk scores for Salmonella spp. and L. monocytogenes in processed pork or poultry-meat products (ready-to-eat or to be reheated) and partially cooked pork products were also obtained (low risk population). Scores for Staphylococcus aureus , Clostridium perfringens and Bacillus cereus and various product types were mostly in the “medium” risk category, except for S. aureus /ready-to-eat pork products able to support growth of the organism, which fell into the high risk category. Campylobacter spp. gave moderate risk scores with one exception (raw poultry products), whereas Y. enterocolitica showed combinations of low risk and few of medium risk. High risk pathogen/product combinations identified were: 1) temperature abused, ready-to-eat pork and/or poultry-meat products with extended shelf life and cross-contaminated by L. monocytogenes (high risk population), EHEC (high risk population) or S. aureus (all population), 2) partially cooked or processed intended to be reheated pork products cross-contaminated by L. monocytogenes , served undercooked and receiving improper cooling or reheating (high risk population), and 3) all people consuming undercooked meals cross-contaminated with Campylobacter spp. (e.g. from raw poultry and raw poultry-meat products) and HEV (e.g. from raw pork and raw pork-meat products). Salmonellae gave high risk scores in all food categories (except preserved meat products) for high risk population. Preserved meats (mainly pork) such as dry fermented sausages gave low risk scores. Only Salmonella spp., L. monocytogenes and E. coli EHEC gave moderate risk ratings in case of ingredients likely to be contaminated at an early stage of processing (e.g. animal at slaughter) and inadequate fermentation process. These results may constitute a source of information for hazard assessment during application of a Food Safety Management System.

Researchers describe how Norwalk virus enters intestinal cells
14 Jul 2008
virtualmedicalcentre.com [edited] [iFSN]
Nearly 30 years ago, scientists studying the Norwalk virus – a virulent intestinal bug – found that as many as 20 percent of individuals exposed to it resisted infection. Later, they determined that the resistance resulted from specific factors in their blood that determined blood type. In a paper that appears online in the current issue of the Proceedings of the National Academy of Sciences, Dr. B. V Venkataram Prasad, professor of biochemistry and molecular biology at Baylor College of Medicine and his colleagues describe the intricate structure of the interactions between the capsid or surface protein of the Norwalk virus and the histo-blood group antigens, which determine blood type. Using X-ray crystallography, they described not only the surface protein of the virus but also the complex formed between it and the blood group antigens. The finding gives a clue about how this family of viruses has evolved and perhaps how it will change in the future. The BCM researchers found that the histo-blood group antigens A (blood type A) and H (blood type O) bind to the capsid or surface of the virus in the same place, projecting outward from the surface of the virus.
(Source: Proceedings of the National Academy of Sciences: Baylor College of Medicine: July 2008)

Transporters of arsenite in rice and their role in arsenic accumulation in rice grain
11 July 2008
Proceedings of the National Academy of Sciences (PNAS)
Jian Feng Ma, Naoki Yamaji, Namiki Mitani, Xiao-Yan Xu, Yu-Hong Su, Steve P. McGrath, and Fang-Jie Zhao Arsenic poisoning affects millions of people worldwide. Human arsenic intake from rice consumption can be substantial because rice is particularly efficient in assimilating arsenic from paddy soils, although the mechanism has not been elucidated. Here we report that two different types of transporters mediate transport of arsenite, the predominant form of arsenic in paddy soil, from the external medium to the xylem. Transporters belonging to the NIP subfamily of aquaporins in rice are permeable to arsenite but not to arsenate. Mutation in OsNIP2;1 (Lsi1, a silicon influx transporter) significantly decreases arsenite uptake. Furthermore, in the rice mutants defective in the silicon efflux transporter Lsi2, arsenite transport to the xylem and accumulation in shoots and grain decreased greatly. Mutation in Lsi2 had a much greater impact on arsenic accumulation in shoots and grain in field-grown rice than Lsi1. Arsenite transport in rice roots therefore shares the same highly efficient pathway as silicon, which explains why rice is efficient in arsenic accumulation. Our results provide insight into the uptake mechanism of arsenite in rice and strategies for reducing arsenic accumulation in grain for enhanced food safety.

E. coli O157:H7 vaccine data presented to World Buiatrics Congress in Budapest, Hungary
10 Jul 2008
from a press relese [edited] [iFSN]
Bioniche Life Sciences Inc. (TSX: BNC), a research-based, technology-driven Canadian biopharmaceutical company, presented data regarding its E. coli O157:H7 cattle vaccine at the XXV World Buiatrics Congress in Budapest, Hungary today. The presentation was made by Dr. Dragan Rogan, Vice-President, Bioniche Animal Health Research & Development. It was entitled, "Vaccination of Cattle with E. coli O157:H7 Type III Secretion Proteins as a Pre-Slaughter Intervention Method to Reduce E. coli O157:H7 Prevalence", and was co-authored by Dr. David Smith, Dr. Rod Moxley, Dr. Andy Potter and Julie Yome. The World Buiatrics Congress is the largest event of its kind in the cattle industry. The Bioniche vaccine is the world's first vaccine that may be used as an on-farm intervention to reduce the amount of E. coli O157:H7 shed by cattle. In his presentation in Budapest, Dr. Rogan summarized numerous studies that have been completed with the Bioniche vaccine over the last five years involving more than 30,000 cattle.

Alternative hand contamination technique to compare the activities of antimicrobial and nonantimicrobial soaps under different test conditions
10 Jul 2008
AEM
Janice L. Fuls, Nancy D. Rodgers, George E. Fischler, Jeanne M. Howard, Monica Patel, Patrick L. Weidner, and Melani H. Duran
The Dial Corporation, Microbiology Department, 15101 N. Scottsdale Rd., Scottsdale, Arizona 85254
Received 25 October 2007/ Accepted 19 April 2008
Antimicrobial hand soaps provide a greater bacterial reduction than nonantimicrobial soaps. However, the link between greater bacterial reduction and a reduction of disease has not been definitively demonstrated. Confounding factors, such as compliance, soap volume, and wash time, may all influence the outcomes of studies. The aim of this work was to examine the effects of wash time and soap volume on the relative activities and the subsequent transfer of bacteria to inanimate objects for antimicrobial and nonantimicrobial soaps. Increasing the wash time from 15 to 30 seconds increased reduction of Shigella flexneri from 2.90 to 3.33 log10 counts (P = 0.086) for the antimicrobial soap, while nonantimicrobial soap achieved reductions of 1.72 and 1.67 log10 counts (P > 0.6). Increasing soap volume increased bacterial reductions for both the antimicrobial and the nonantimicrobial soaps. When the soap volume was normalized based on weight (~3 g), nonantimicrobial soap reduced Serratia marcescens by 1.08 log10 counts, compared to the 3.83-log10 reduction caused by the antimicrobial soap (P < 0.001). The transfer of Escherichia coli to plastic balls following a 15-second hand wash with antimicrobial soap resulted in a bacterial recovery of 2.49 log10 counts, compared to the 4.22-log10 (P < 0.001) bacterial recovery on balls handled by hands washed with nonantimicrobial soap. This indicates that nonantimicrobial soap was less active and that the effectiveness of antimicrobial soaps can be improved with longer wash time and greater soap volume. The transfer of bacteria to objects was significantly reduced due to greater reduction in bacteria following the use of antimicrobial soap.

Cleaning methods for fresh produce
06 Jul 2008
Horticulture Week - Linda Everis [edited] [iFSN]
The study, published in 2006 by the Fresh Prepared Salads Producer Group, evaluated the presence of disinfectant by-products on fresh produce washed in chlorinated water. Produce was washed and 12 leachate [a product or solution formed by leaching] samples were analysed for the presence of a number of organochlorine compounds such as chloramine, chloroacetic acid and total trihalomethanes. These were then compared to UK and US drinking water standards. Results indicated that of all the tests done, only one sample exceeded the US standard for trichloroaceticacid. The group also estimated intake levels of these compounds based on average and extreme salad consumption and concluded that a 150g bag of salad contains fewer chlorine compounds than a 250ml glass of tap water and is no cause for concern. Current popular alternatives to chlorine washing include chlorine dioxide and organic acids. There is also a trend to move towards the use of organic acids for the washing of fresh produce. There are some commercially available wash agents containing mixes of organic acids that are currently used to wash fresh produce. There are many other techniques that are being investigated as potential alternatives to chlorine. These include UV, ultrasound, ozone, irradiation, electrolysed water, peracetic acid, hot water, bio-control agents and natural compounds like essential oils. Sequential washing - where produce is washed a number of times with either the same wash agent or different agents - is also being studied.

Adhesion to and viability of Listeria monocytogenes on food contact surfaces
01 July 2008
Journal of Food Protection, Volume 71, Number 7, July 2008, pp. 1379-1385(7)
Silva, Sónia; Teixeira, Pilar; Oliveira, Rosário; Azeredo, Joana
Listeria monocytogenes is an important pathogen responsible for major outbreaks associated with food products. Adhesion to surfaces leads to significant modifications in cell physiology. The aim of this work was to determine the adhesion ability of 10 isolates of L. monocytogenes to eight materials commonly used in kitchens and to evaluate the viability of the adhered cells. The materials assayed were stainless steel 304, marble, granite, glass, polypropylene from a bowl and from a cutting board, and two kinds of silestone. All L. monocytogenes strains attached to all surfaces, although to different extents. L. monocytogenes adhered most tightly to granite and marble, followed by stainless steel 304, glass, silestones, and finally polypropylene surfaces. Surfaces at the threshold between hydrophobicity and hydrophilicity, with high electron acceptor capability and a regular pattern of roughness, were more prone to attachment. Polypropylene surfaces displayed the highest percentage of viable bacteria (nearly 100%), whereas marble and granite had a lower percentage of cultivable cells, 69.5 and 78.7%, respectively. The lowest percentage of culturable bacteria was found on white silestone (18.5%). These results indicate that there are differences in adhered cell viability on different materials. Cell viability assays are important to better understand the cross-contamination process because only adhered bacteria that remain viable are responsible for postprocess contamination.

A qualitative assessment of toxoplasma gondii risk in ready-to-eat smallgoods processing
01 Jul 2008
Journal of Food Protection , Volume 71, Number 7, July 2008 , pp. 1442-1452(11)
Mie, Tanya; Pointon, Andrew M.; Hamilton, David R.; Kiermeier, Andreas
Toxoplasma gondii is one of the most common parasitic infections of humans and other warm-blooded animals. In most adults, it does not cause serious illness, but severe disease may result from infection in fetuses and immunocompromised people. Consumption of raw or undercooked meats has consistently been identified as an important source of exposure to T. gondii . Several studies indicate the potential failure to inactivate T. gondii in the processes of cured meat products.
This article presents a qualitative risk-based assessment of the processing of ready-to-eat smallgoods, which include cooked or uncooked fermented meat, pâté, dried meat, slow cured meat, luncheon meat, and cooked muscle meat including ham and roast beef. The raw meat ingredients are rated with respect to their likelihood of containing T. gondii cysts and an adjustment is made based on whether all the meat from a particular source is frozen. Next, the effectiveness of common processing steps to inactivate T. gondii cysts is assessed, including addition of spices, nitrates, nitrites and salt, use of fermentation, smoking and heat treatment, and the time and temperature during maturation. It is concluded that processing steps that may be effective in the inactivation of T. gondii cysts include freezing, heat treatment, and cooking, and the interaction between salt concentration, maturation time, and temperature. The assessment is illustrated using a Microsoft Excel-based software tool that was developed to facilitate the easy assessment of four hypothetical smallgoods products.

Disease-detecting lab in the palm of your hand
01 Jul 2008
ICT Results [edited] [iFSN]
Detecting food-borne diseases such as Campylobacter and Salmonella long before they enter the food chain would help ensure that the dinner on your table is safe to eat.
There is no quick and simple way to detect infectious bacteria on farms, or even in food processing and distribution plants. Samples have to be sent to labs for testing, a process that can take hours or days The idea of a lab-on-a-chip, a device small enough for someone to carry around but able to perform many of the tests normally carried out in a full-sized laboratory, has been around ever since microelectromechanical systems (mems) technology made it possible to put sensors, fluid channels and optical components into a small space. However, the costs of producing such a system and the failure of many developers to incorporate a means of preparing samples on the spot has meant that few have gone into commercial use. A team of European researchers has addressed those problems, creating one of only two prototype systems in the world that prepare samples and perform DNA tests on bacteria in a portable, easy-to-use and cost-effective chip. Their work, carried out in the EU-funded OptoLabCard project, will lead to the development of portable devices that can detect bacteria in the food chain and diseases as diverse as cancer, hepatitis, AIDS and flu in humans. Their work could also be used to develop portable devices that can identify pathogens and pollution in water supplies

Effective household disinfection methods of kitchen sponges
08 Jun 2008
Food Control (Volume 20, Issue 3, March 2009, Pages 310-313) [iFSN]
Manan Sharma, Janet Eastridge and Cheryl Mudd Abstract
Abstract
Several household disinfecting treatments to reduce bacteria, yeasts and molds on kitchen sponges were evaluated. Sponges were soaked in 10% bleach solution for 3 min, lemon juice (pH 2.9) for 1 min, or deionized water for 1 min, placed in a microwave oven for 1 min at full power, or placed in a dishwasher for full wash and drying cycles, or left untreated (control). Microwaving and dishwashing treatments significantly lowered (P < 0.05) aerobic bacterial counts (<0.4 log and 1.6 log CFU/sponge, respectively) more than any chemical treatment or control (7.5 CFU/sponge). Counts of yeasts and molds recovered from sponges receiving microwave (<0.4 log CFU/sponge) or dishwashing (0.4 log CFU/sponge) treatments were significantly lower than those recovered from sponges immersed in chemical treatments. Our study shows that microwaving and dishwashing treatments may kill foodborne pathogens in a household kitchen environment.

Protein found to promote antibiotic resistance in a common foodborne pathogen
05 June 2008
Iowa State University [edited] [iFSN]
Researchers from Iowa State University have identified a novel factor that promotes the development of antibiotic resistance in a bacterial pathogen. The study, published June 6th in the open-access journal PLoS Pathogens, explains that Mfd, a protein involved in DNA transcription and repair, plays an important role in the development of fluoroquinolone resistance in Campylobacter , a bacterial pathogen commonly associated with food poisoning in humans. It is reported that these findings have uncovered a previously unrecognized role of Mfd in promoting mutations conferring antibiotic resistance. Despite its importance, Mfd is not the only factor influencing the mutation frequency and future studies will be needed to determine how Mfd increases the emergence of antibiotic-resistant mutants.

Study shows copper surfaces kill C. diff bacteria
03 June 2008
The Copper Development Association [edited] [iFSN]
Scientists in the Environmental Healthcare Unit at the University of Southampton in the U.K. have found that infectious bacterium Clostridium difficile is killed when exposed to surfaces made of copper and its alloys, brass and bronze. The results of the study have been published in the February 2008 issue of the Journal of Hospital Infection.

Reducing absenteeism from gastrointestinal and respiratory illness in elemtary school students: A randomized, controlled trial of an infection-control intervention
02 June 2008
Pediatrics
Thomas J. Sandora, MD, MPH, Mei-Chiung Shih, PhD and Donald A. Goldmann, MD [edited] [iFSN]
BACKGROUND . Students often miss school because of gastrointestinal and respiratory illnesses. We assessed the effectiveness of a multifactorial intervention, including alcohol-based hand-sanitizer and surface disinfection, in reducing absenteeism caused by gastrointestinal and respiratory illnesses in elementary school students.
METHODS . We performed a school-based cluster-randomized, controlled trial at a single elementary school. Eligible students in third to fifth grade were enrolled. Intervention classrooms received alcohol-based hand sanitizer to use at school and quaternary ammonium wipes to disinfect classroom surfaces daily for 8 weeks; control classrooms followed usual hand-washing and cleaning practices. Parents completed a preintervention demographic survey. Absences were recorded along with the reason for absence. Swabs of environmental surfaces were evaluated by bacterial culture and polymerase chain reaction for norovirus, respiratory syncytial virus, influenza, and parainfluenza 3. The primary outcomes were rates of absenteeism caused by gastrointestinal or respiratory illness. Days absent were modeled as correlated Poisson variables and compared between groups by using generalized estimating equations. Analyses were adjusted for family size, race, health status, and home sanitizer use. We also compared the presence of viruses and the total bacterial colony counts on several classroom surfaces.
RESULTS. A total of 285 students were randomly assigned; baseline demographics were similar in the 2 groups. The adjusted absenteeism rate for gastrointestinal illness was significantly lower in the intervention-group subjects compared with control subjects. The adjusted absenteeism rate for respiratory illness was not significantly different between groups. Norovirus was the only virus detected and was found less frequently on surfaces in intervention classrooms compared with control classrooms (9% vs 29%).
CONCLUSIONS. A multifactorial intervention including hand sanitizer and surface disinfection reduced absenteeism caused by gastrointestinal illness in elementary school students. Norovirus was found less often on classroom surfaces in the intervention group. Schools should consider adopting these practices to reduce days lost to common illnesses.

Analysis of data gaps pertaining to enterotoxigenic Escherichia coli infections in low and medium human development index countries, 1984–2005
01 Jun 2008
Epidemiology and Infection Vol. 136, Issue 6
S.K. Guptaa1 c1, J. Kecka2, P.K. Rama3, J.A. Crumpa1, M. A. Millera4, and E.D. Mintza1
Enterotoxigenic Escherichia coli (ETEC) is a common cause of profuse watery diarrhea in the developing world, often leading to severe dehydration or death. According to this study, the researchers found only 15 population-based studies in low and medium human development index (HDI) countries from 1984 to 2005 that evaluate disease incidence. Reported incidence ranged from 39 to 4460 infections/1000 persons per year. The peak incidence of ETEC appeared to occur between ages 6 and 18 months. A median of 14% (range 2–36%) of diarrheal specimens were positive for ETEC in 19 facility- and population-based studies conducted in all age groups and 13% (range 3–39%) in 51 studies conducted in children only. The study suggested that large population-based studies combined with facility-based studies covering a majority of the corresponding population are needed, especially in low-HDI countries. and a standard molecular definition of ETEC infection is needed to be able to compare results across study sites.

A common, symptom-based case definition for gastroenteritis
01 June 2008
Epidemiology and Infection Volume 136, Issue 07
S.E. Majowicza1a2, G. Halla3, E. Scallana4 c1, G.K. Adaka5, C. Gaucia6, T.F. Jonesa7, S. O’Briena8, O. Henaoa4, and P.N. Sockett
Summary:
National studies determining the burden of gastroenteritis have defined gastroenteritis by its clinical picture, using symptoms to classify cases and non-cases. The use of different case definitions has complicated inter-country comparisons. We selected four case definitions from the literature, applied these to population data from Australia, Canada, Ireland, Malta and the United States, and evaluated how the epidemiology of illness varied. Based on the results, we developed a standard case definition. The choice of case definition impacted on the observed incidence of gastroenteritis, with a 1·5–2·1 times difference between definitions in a given country. The proportion of cases with bloody diarrhoea, fever, and the proportion who sought medical care and submitted a stool sample also varied. The mean age of cases varied by <5 years under the four definitions. To ensure comparability of results between studies, we recommend a standard symptom-based case definition, and minimum set of results to be reported.

Sero-epidemiology as a tool to study the incidence of Salmonella infections in humans
01 June 2008
Epidemiology and Infection Volume 136, Issue 07
J. Simonsena1 c1, M.A. Strida2, K. Molbaka3, K.A. Krogfelta2, A. Linneberga4 and P. Teunisa5
Summary:
Although most foodborne infections are undiagnosed, the incidence of these infections is usually calculated from reported cases. We present a novel population-based method to estimate the incidence of non-typhoid Salmonella infections. From 154 patients with confirmed Salmonella serotype enteritidis infection, we determined the kinetics of the antibody response. The estimated mean responses for the three classes of serum antibodies were combined such that the time from infection could be estimated from antibody measurements. Next, serum samples collected in 1983, 1986, 1992, and 1999 from the general population were analysed for antibodies. We demonstrated how these measurements can be translated into an estimate of the general incidence. Based on serology markers there were 13 exposures leading to seroresponse of Salmonella enteritidis /1000 person-years in 1983; the similar number in 1999 was 217. This trend confirms the increase in the number of culture-confirmed cases reported to the national surveillance system.

Exposure assessment of mycotoxins in dairy milk
28 May 2008
Food Control (Volume 20, Issue 3, March 2009, Pages 239-249)
Rory Coffey, Enda Cumminsa and Shane Ward [iFSN]
Abstract
The objective of this study was to develop a quantitative Monte Carlo exposure assessment model for mycotoxins in dairy milk and to assess the potential human exposure levels. Mean concentrations of mycotoxins in milk were estimated using the simulation model (Aflatoxin M1 = 0.0161 μ g/kg, Ochratoxin A = 0.0002 μ g/kg, Deoxynivalenol = 1 μ g/kg, Fumonisin B1 = 0.36 μ g/kg, Zearalenone = 0.39 μ g/kg, T-2 = 0.0722 μ g/kg) while the simulated tolerable daily intakes (TDIs) from milk for males and females all fell below European Union guidelines. Aflatoxin M1 was the toxin of greatest concern as it had potential to exceed the EU limit of 0.05 μ g/kg in milk. The sensitivity analysis identified the concentration of toxins in maize as the area which needs most attention in relation to crop management and agricultural practice. The sensitivity analysis assessed also identified the carry over rate as a factor closely related to risk and as a factor which required further research.

Occurrence and antimicrobial resistance of Enterococci in retail foods
21 May 2008
Food Control (Volume 20, Issue 3, March 2009, Pages 281-283) [iFSN]
hmet Kolu man, Lale Sariye Akan and Funda Pınar Çakiroğlu Abstract This study aimed to show the vancomycin-resistant Enterococci VRE contamination and antibiotic resistance profiles of Enterococcus spp. in different kinds of food acquired from various markets between January 2007 and June 2007. Two hundred samples were used in the research. They consisted of 50 samples of meat (20 chicken, 20 beef, 10 fish), 50 samples of cheese (20 cheddar, 20 Turkish white, 10 cream), 50 samples of RTE (10 burgers, 10 pizzas, 10 chicken nuggets, 10 milk deserts, 5 beef roast and 5 salads), 30 samples of spice (10 black pepper, 10 red pepper, 10 curry) and 20 samples of yogurt. The results of the study indicated high levels of contamination with Enterococcus spp. in 100 of all the samples (50 %). The highest resistance was recorded for a cream cheese sample, with resistance to 12 types of antibiotics. The lowest resistance was in a chicken sample, with resistance to 2 types of antibiotics. Only 4 strains were identified as vancomycin-resistant Enterococcus (VRE), four of which were E. faecalis and originated from chicken. The results of this study underline the public health implications of VRE and the urgency about the preventive measures that must be taken to control the antibiotic use at farm level.

Nitrate, nitrite and nitric oxide in gastric mucosal defense
14 May 08
Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Cell Biology - Joel Petersson
The human stomach normally contains high levels of bioactive nitric oxide (NO). This NO derives from salivary nitrate (NO3-) that is converted to nitrite (NO2-) by oral bacteria and thereafter non-enzymatically reduced in the acidic gastric lumen to NO. Nitrate is a common component in vegetables, Hence, intake of nitrate-rich vegetables results in high levels of NO in the stomach. The physiological effects of the high concentration of NO gas normally present in the gastric lumen have been hitherto unknown, and the present investigations were therefore conducted to address this issue. In summary, this thesis challenges the current dogma that nitrate intake is hazardous, and on the contrary suggests that dietary nitrate plays a direct role in regulating gastric homeostasis. It is likely that a sufficient supply of nitrate in the diet together with the oral microflora is essential for preventing pathological conditions in the gastrointestinal tract.

Smart microbes - Bacteria anticipate changing environments
8 May 2008
By Patrick Barry – Science News - Web edition
According to this story, new research shows that even bacteria can evolve to predict upcoming events based on clues, like a dog salivating at the sound of the dinner bell. It is reported that the discovery reveals a kind of predictive intelligence in how microbes interpret sensory cues from their environments. Understanding how this predictive ability affects bacteria's behavior could help scientists control microbes better, benefiting industry and the treatment of infectious diseases.

Cyclospora
02 May 2008
Institute of Food Science and Technology
The growing importance of the protozoan parasite, Cyclospora cayetanensis , as a cause of foodborne infection is described. Outbreaks so far have occurred mainly in the USA and have been linked to the consumption of soft fruits and salad greens. The microbiological safety of such fresh fruit and salad vegetables depends on the avoidance of contamination with pathogenic microorganisms at all stages of production, most particularly in the field. IFST outlines the measures needed to avoid such contamination and stresses the need for improved reporting mechanisms. Cyclospora full statement

Leaf age may contribute to contamination of lettuce with E. coli and Salmonella
25 Apr 2008
Science Daily
A new study presents the first evidence that harmful pathogens frequently linked with food-borne illnesses are more commonly found on younger inner leaves than on older outer leaves of romaine lettuce. The researchers from the Produce Safety and Microbiology Research Unity, Albany, California and the University of California, Berkley report their findings in the journal Applied and Environmental Microbiology. In the study researchers investigated the growth of E. coli O157:H7 and S. enterica on romaine lettuce leaves both pre- and post-harvest. Both bacterial pathogens displayed higher population rates on younger leaves than on middle leaves harvested from mature lettuce heads.
Journal reference: M.T. Brandl, R. Amundson. 2008. Leaf age as a risk factor in contamination of lettuce with Escherichia coli O157:H7 and Salmonella enterica . Applied and Environmental Microbiology, 74. 8: 2298-2306. Adapted from materials provided by American Society for Microbiology, via EurekAlert!, a service of AAAS.

Protozoa may enable food-borne pathogens on leafy vegetables
25 Apr 2008
Science Daily
Protozoa found on lettuce and spinach may sequester harmful food-borne pathogens ultimately contributing to their survival on produce surfaces say researchers from Tennessee Technological University, Cookeville and the Produce Safety and Microbiology Research Unit, Albany, California. Protozoa are single-celled organisms whose main function is bacterial consumption. They are commonly found in the natural microflora of plants and several species of amoebae have been associated with fresh salad vegetables. The study rsults showed Glaucoma produced vesicles with all bacterial strains. The presence of protozoa on leafy vegetables and their sequestration of enteric bacteria in vesicles indicate that they may play an important role in the ecology of human pathogens on produce," say the researchers.
Journal reference: P. Gourabathini, M.T. Brandl, K.S. Redding, J.H. Gunderson, S.G. Berk. 2008. Interactions between food-borne pathogens and protozoa isolated from lettuce and spinach. Applied and Environmental Microbiology, 74. 8: 2518-2525. Adapted from materials provided by American Society for Microbiology, via EurekAlert!, a service of AAAS.

Fruit flies show how Salmonella escapes immune defenses
16 Apr 2008
Emory University [edited]
Salmonella are wily and obnoxious bacterial invaders--escape artists capable of evading multiple immune responses and causing a harsh and debilitating intestinal infection. Researchers have come closer to understanding how these bacteria manage to thwart two major categories of immune defences at once and set up shop in a host organism. New results are reported in the April 2008 issue of the journal Cell Host & Microbe. The Emory University research team used a transgenic fruit fly (drosophila) model to test a group of "effector proteins," also known as "virulence factors," secreted by invading organisms to usurp the host immune response for their own benefit. They found that one of these proteins, named AvrA, not only shuts down the key immune signaling pathways JNK and NF-kB, but also turns off the fail safe system organisms have evolved to respond to irreversible threats. This ultimate immune defense, called apoptosis, eliminates invaders along with the infected cells through a system of programmed cell death.

Convergence of Campylobacter species: Implications for bacterial evolution
10 Apr 2008
Science Magazine, Vol. 320. no. 5873
Samuel K. Sheppard, Noel D. McCarthy, Daniel Falush, Martin C. J. Maiden
The nature of species boundaries in bacteria remains controversial. In particular, the mechanisms of bacterial speciation and maintenance in the face of frequent genetic exchange are poorly understood. This story reported patterns of genetic exchange that show two closely related zoonotic pathogenic species, Campylobacter jejuni and Campylobacter coli, are converging as a consequence of recent changes in gene flow. Population expansion into a novel ecological niche generated by human activity is the most probable explanation for the increase in genetic exchange between these species. Bacterial speciation can therefore occur by mechanisms analogous to those seen in metazoans, where genetic diversification and incipient speciation caused by ecological factors have been reported in several genera.

Dr. Mom was right--and wrong--about washing fruits and vegetables
10 Apr 2008
Science Daily [edited]
Adapted from materials provided by American Chemical Society, via EurekAlert!, a service of AAAS.
Washing fresh fruits and vegetables before eating may reduce the risk of food poisoning and those awful episodes of vomiting and diarrhea. But according to new research, described today at the 235th national meeting of the American Chemical Society, washing alone -- even with chlorine disinfectants -- may not be enough. New findings from scientists at the U.S. Department of Agriculture suggest that irradiation, a food treatment currently being reviewed by the FDA, can effectively kill internalized pathogens that are beyond the reach of conventional chemical sanitizers. Irradiation exposes food to a source of electron beams, creating positive and negative charges. It disrupts the genetic material of living cells, inactivating parasites and destroying pathogens and insects in food, including E. coli and Salmonella. Using this technique on fresh and fresh-cut fruits and vegetables could provide a reliable way to reduce the numbers of foodborne illnesses reported each year in the United States, says Brendan A. Niemira, Ph.D., a microbiologist with the USDA's Agricultural Research Service in in Wyndmoor, Pa., who directed the study.

Potential human transmissibility of BASE prion
1 Apr 2008
Journal of Virology [edited] [Promed]
[Ref: Evaluation of the human transmission risk of an atypical bovine spongiform encephalopathy prion strain. J Virol. April 2008; 82(7):3697-701. Epub 30 Jan 2008] Qingzhong Kong et al.
Abstract: Bovine spongiform encephalopathy (BSE), the prion disease in cattle, was widely believed to be caused by only one strain, BSE-C. BSE-C causes the fatal prion disease named new variant Creutzfeldt-Jakob disease in humans. Two atypical BSE strains, bovine amyloidotic spongiform encephalopathy (BASE, also named BSE-L) and BSE-H, have been discovered in several countries since 2004; their transmissibility and phenotypes in humans are unknown. We investigated the infectivity and human phenotype of BASE strains by inoculating transgenic (Tg) mice expressing the human prion protein with brain homogenates from 2 BASE strain-infected cattle. Sixty percent of the inoculated Tg mice became infected after 20 to 22 months of incubation, a transmission rate higher than those reported for BSE-C. A quarter of BASE strain-infected Tg mice, but none of the Tg mice infected with prions causing a sporadic human prion disease, showed the presence of pathogenic prion protein isoforms in the spleen, indicating that the BASE prion is intrinsically lymphotropic. The pathological prion protein isoforms in BASE strain-infected humanized Tg mouse brains are different from those from the original cattle BASE or sporadic human prion disease. Minimal brain spongiosis and long incubation times are observed for the BASE strain-infected Tg mice. These results suggest that in humans, the BASE strain is a more virulent BSE strain and likely lymphotropic.

Occurrence of Listeria and Enterobacteriaceae in domestic refrigerators
15 Mar 2008
Journal of Food Protection - Kilonzo-Nthenge, Agnes; Chen, Fur-Chi; Godwin, Sandria L.
Consumers' refrigeration practices have a significant impact on the safety and quality of foods. To determine the prevalence and the identity of microorganisms in domestic refrigerators, swab samples were taken from various locations in the refrigerators from 137 households in middle Tennessee. The swabs were inoculated into different media, and standard procedures were used to characterize the isolates. Resistance to antibiotics was most common in erythromycin (39.9%), followed by ampicillin (33.8%), cefoxitin (12.8%), tetracycline (5%), streptomycin (4.0%), nalidixic acid (2.1%), kanamycin (1.4%), and colistin (0.7%). None of the isolates tested was resistant to ciprofloxacin or gentamycin. Listeria spp. were also detected in six refrigerators. These findings underline the need for greater consumer education regarding proper refrigerator cleaning and safe food handling practices.

Thermal inactivation D- and Z-values of multidrug-resistant and non-multidrug-resistant Salmonella serotypes and survival in ground beef exposed to consumer-style cooking
15 Mar 2008
Journal of Food Protection
Stopforth, J.D.; Suhalim, R.; Kottapalli, B.; Hill, W.E.; Samadpour, M.
There has been speculation that multidrug-resistant (MDR) strains are generated by subtherapeutic antibiotic use in food animals and that such strains result in increased resistance to lethality by food processes such as heat and irradiation. The objective of this study was to evaluate the heat resistance of 20 strains, namely an MDR and a non-multidrug-resistant (NMDR) strain of each of 10 Salmonella serotypes isolated from cattle or cattle environments. MDR and NMDR Salmonella serotypes studied included montevideo, typhimurium, anatum, muenster, newport, mbandaka, dublin, reading, agona , and give . Although there was no overall significant difference in the heat resistance of MDR and NMDR serotypes, NMDR serotypes generally appeared to have slightly higher heat resistance than NMDR serotypes, especially at 55 and 60°C. The highest relative heat resistance (highest z-values) was exhibited by Salmonella anatum . For phase II, three serotypes (regardless of resistance profile) with the highest relative heat resistance and their drug-resistant counterparts were selected for thermal inactivation in ground beef patties cooked to endpoint temperatures. Salmonella agona was able to survive in ground beef cooked to an internal temperature of 71°C. Results of these studies suggest drug resistance does not affect the heat resistance of Salmonella and that serotype or strain is an important consideration in risk assessment of the pathogen with regard to survival at cooking temperatures.

Diluting the deadly effects of anthrax - with a nice cup of tea
14 Mar 2008
Western Mail [edited]
Scientists from a Welsh university have discovered a potential antidote to the deadly bio-terrorism weapon anthrax -- the humble cup of tea. The team of researchers, led by Cardiff University anthrax expert Professor Les Baillie of the Welsh School of Pharmacy, stumbled upon tea's ability to kill the deadly bacteria after trying to prove its medical benefits to their American colleagues. While working with Doctor Theresa Gallagher and her team at the Biodefense Institute, part of the Medical Biotechnology Centre of the University of Maryland in Baltimore, the 2 groups of scientists tested the effects of tea and coffee on anthrax, or Bacillus anthracis . But that's tea without milk. The scientists found that adding milk negated tea's antibacterial qualities, leaving it useless against the biological weapon. Researchers now hope to use their findings from studying anthrax in America to help their understanding of Clostridium difficile , the harmful bacteria which are suspected to have caused a number of deaths, including 90 people at a hospital in Kent from April 2004 to September 2006. The team at Cardiff University said they would like to be able to apply their science to save lives in Wales and across the world.

Decontamination of fluid milk containing Bacillus spores using commercial household products
01 Mar 2008
Journal of Food Protection
Black, D.G.; Taylor, T.M.; Kerr, H.J.; Padhi, S.; Montville, T.J.; Davidson, P.M.
Abstract:
Studies were conducted to test the efficacy of commercial household products for inactivating spores of Bacillus cereus (used as a surrogate for B. anthracis ) in vitro and in fluid milk. Validation of the resistance of the B. cereus spores was confirmed with B. anthracis spores. Fifteen commercial products, designed as either disinfectants or sanitizers or as potential sanitizers, were purchased from retail markets. Compounds were diluted in water (in vitro) or in 2% fat fluid milk, and spores were exposed for up to 6 h. Products containing hypochlorite were most effective against B. cereus spores. Products containing HCl or H2O2 also reduced significant numbers of spores but at a slower rate. Therefore, several household products on the market may be used to decontaminate fluid milk or similar food products contaminated by spores of B. anthracis

Pathogen detection and control in fresh broccoli sprouts
28 Feb 2008
Nutrition Journal Jed W Fahey, Philippe J Ourisson and Frederick H Degnan
The recent increased interest in consuming green vegetable sprouts has been tempered by the fact that fresh sprouts can in some cases be vehicles for foodborne illnesses. A one year program of microbial hold-and-release testing, conducted in concert with strict seed and facility cleaning procedures by 13 U.S. broccoli sprout growers was evaluated. By using a "test-and-re-test" protocol, growers were able to minimize crop destruction. By pooling drums for testing, they were also able to reduce testing costs which now represent a substantial portion of the costs associated with sprout growing. The test-and-hold scheme described herein allowed those few batches of contaminated sprouts to be found prior to packaging and shipping. These events were isolated, and only safe sprouts entered the food supply.

Tips from the Journals of the American Society for Microbiology: Gastric acid may help protect against foodborne diseases
21 Feb 2008
EurekAlert!
A new study suggests that low levels of gastric acid in the stomach can increase one’s likelihood of getting a foodborne infection. The researchers from Australia report their findings in the February 2008 issue of the journal Infection and Immunity. One of the three main functions ascribed to gastric acid is inhibiting infectious agents from reaching the intestine and distribution levels noted in fish, amphibians, reptiles, birds and mammals indicate evolutionary advantages. In the study healthy mice and hypochlorhydric mice were infected with Yersinia enterocolitica, Salmonella enterica Serovar Typhimurium, Citrobacter rodentium and Clostridium perfringens and then monitored for their ability to fight infection. Results showed that significantly higher numbers of all four pathogens survived in the hypochlorhydric mice. Further studies indicated that infected mice treated with antacids were more sensitive to infection due to the absence of stomach acid. The researchers claimed that their model provides an excellent system with which to investigate the effects of hypochlorhydria on susceptibility to infection and to evaluate the in vivo susceptibility to gastric acid of orally administered therapies, such as vaccines and probiotics. (S.M. Tennant, E.L. Hartland, T. Phumoonna, D. Lyras, J.I. Rood, R.M. Robins-Browne, I.R. van Driel. 2008. Influence of gastric acid on susceptibility to infection with ingested bacterial pathogens. Infection and Immunity, 76. 2: 639-645.)

Cleaner water through nanotechnology
20 Feb 2008
EurekAlert T
Tiny particles of pure silica coated with an active material could be used to remove toxic chemicals, bacteria, viruses, and other hazardous materials from water much more effectively and at lower cost than conventional water purification methods, according to researchers writing in the current issue of the International Journal of Nanotechnology. The researchers have investigated how silica particles can be coated easily with a nanometer-thin layer of active material based on a hydrocarbon with a silicon-containing anchor. They point out that the filtration process occurs through an electrostatic attraction between the pathogens and the surface engineered particles. The recent report entitled 'Water for People - Water for Life' of the World Water Assessment Program of the UNESCO says that more than 6000 people die every day due to water-related diseases, including diarrhea, worm infections, and infectious diseases. In addition, organic pollutants from industrial waste water from pulp and paper mills, textiles and leather factories, steel foundries, and petrochemicals refineries, are a major cause of illness in parts of the world where regulations do not necessarily protect people from such industrial outflows. The team's nanotech approach to water purification could help prevent disease and poisoning for potentially millions of people.

Earthworms found to contain chemicals from households and animal manure: Study
20 Feb 2008
U.S. Department of the Interior, U.S. Geological Survey Office of Communication
Jennifer La Vista, Edward T. Furlong
Earthworms studied in agricultural fields have been found to contain organic chemicals from household products and manure, indicating that such substances are entering the food chain. U.S. Geological Survey Scientists and their colleague from Colorado State University at Pueblo published their new findings today in Environmental Science and Technology. Scientist collected earthworms from a soybean field fertilized with biosolids. The earthworms were analyzed for 77 different chemicals; 20 chemicals were detected in the earthworms. Scientists found 28 AWIs in biosolids being applied at a soybean field for the first time and 20 AWIs in earthworms from the same field. Similar results were found for the field where swine manure was applied. Several compounds were detected in earthworms collected both from the biosolids- and manure-applied fields, including phenol (disinfectant), tributylphosphate (antifoaming agent and flame retardant), benzophenone (fixative), trimethoprim (antibiotic), and the synthetic fragrances galaxolide, and tonalide. This study is part of a long-term effort by the USGS Toxic Substances Hydrology Program to determine the fate and effects of chemicals of emerging environmental concern in aquatic and terrestrial environments, and to provide water-resource managers with objective information that assists in the development of effective water management practices. It was funded in part by a Research Corporation Cottrell College Award and a Faculty Research Grant from Eastern Washington University. More information can be found by reading, "Biosolids, Animal Manure, and Earthworms: Is There a Connection?"


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