Recent Studies presented in the 107th General Meeting of the American Society for Microbiology, indicates that we humans may be eating food that is causing a rise in antibiotic resistant infections.
Dr. Hua Wang (Ohio State university) who presented the study said that the food we eat could be an important source of this antibiotic resistant evolution in microbes. Over the past few years, normal infection like malaria, flu and many more are becoming more and more dangerous as the microbes have been developing antibiotic resistance. This makes it harder to treat the patient as the regular antibiotics are to able to fight the disease causing microbes. Earlier on this rise in resistance was attributed to the fact that doctors and physicians were more easily prescribing powerful antibiotic to patients thus flooding the general population with these drugs. Thus it allowed the very few number of resistant varieties of microbes to grow in number and now cause the problem we face.
Studies now show that food intake may also be a key factor that has led to rise in these resistant varieties. The way microbes may gain antibiotic resistance is through a process called Horizontal Gene Transfer." this is a process by which bacteria in close proximity to each other can share genetic information thus making non resistant varieties, resistant. This problem is not being studied further in greater detail as it may present a huge problem for Modern Medicine.
Another scary fact is that is has also been shown that babies who have been feed only on breast milk also show the presence of these resistant varieties of microbes in their intestines. This, means that he source of these microbes can also be outside the food supply. Thus now environmental factors are also being studies as a vector form to transfer genetic information from resistant varieties to non-resistant varieties.
Dr. Hua is currently working on methods by which resistant genes can be minimized in our foods. So next time you buy something from the supermarket make sure you cook it nicely and you know exactly what is the source of your food products.
Wednesday, May 30, 2007
Tuesday, May 29, 2007
Sustainability, Infection Prevention, Evidence-Based Design Among Trends in $41 Billion Healthcare Construction Industry
SAN FRANCISCO--The $41 billion healthcare construction industry is going green as it anticipates growing 11 percent in 2007, according to a Health Technology Center (HealthTech) study. HealthTech reports that sustainability principles are lowering energy costs, creating environments less prone to the spread of infection, and reducing the carbon footprint of health facilities.
U.S. hospitals are discovering that sustainable design practices not only reduce energy costs, but lower infection rates, according to the study. Technologies – such as motion sensors for lights, faucets, and doorways – reduce the transmission of infections as well as lowering the $5.3 billion spent annually on energy.
“The high cost of energy and operations, coupled with increasing environmental consciousness, has elevated the importance of green design for healthcare facilities,” said Molly J. Coye, MD, CEO of HealthTech. “Green technology investment has become cost-effective and pays for itself within a few years.”
Principles that reduce hospital acquired infection rates and manage the prevalence of multi-drug resistant organisms is another critical trend in healthcare facility design. Wireless communications, RFID tracking, anti-microbial surfaces, negative pressure isolation rooms, single patient rooms, and emergency department entrance alternatives are used to reduce infections, which claim up to 100,000 lives every year.
Another trend is the use of evidence-based design to assure that facilities support clinical efficiency, patient safety, and deployment of emerging information and clinical technologies.
“Hospital CEO’s face significant financial challenges. They want evidence that care environments are improving patient outcomes and workforce efficiency,” said Steven DeMello, director of research and forecasting for HealthTech.
Design research databases, modeling and simulation, virtual environments, process software, and manufacturing quality techniques (e.g. LEAN, Six Sigma) are among the tools increasingly used by hospitals and design firms, according to DeMello.
The report profiles several organizations that have successfully acted on these trends, including:
The Patrick H. Dollard Discovery Health Center in upstate New York which is saving $50,000 annually more than projected after designing the facility to become a Leadership in Energy and Environment Design certified facility;
Sutter Health’s in California and in Seattle Virginia Mason’s use of LEAN principles to design a hospital and improve process flow, respectively;
Peace Health in the Pacific Northwest participated in the Pebble Project (researching effect of facility design on quality of care and financial performance) to install patient lifts and booms, resulting in 99% fewer injuries;
Multi-state Kaiser Permanente development with a carpet manufacturer of a PVC-free carpet with the same performance as vinyl carpeting.
HealthTech (healthtech.org) is a research organization and expert network that offers its partner hospitals and health systems proprietary reports, decision support tools, and educational events for adopting care delivery innovations and deploying emerging technologies. Partners develop a competitive advantage by using HealthTech’s resources to redesign care, plan future facilities, prioritize technology investments and avoid costly errors.
U.S. hospitals are discovering that sustainable design practices not only reduce energy costs, but lower infection rates, according to the study. Technologies – such as motion sensors for lights, faucets, and doorways – reduce the transmission of infections as well as lowering the $5.3 billion spent annually on energy.
“The high cost of energy and operations, coupled with increasing environmental consciousness, has elevated the importance of green design for healthcare facilities,” said Molly J. Coye, MD, CEO of HealthTech. “Green technology investment has become cost-effective and pays for itself within a few years.”
Principles that reduce hospital acquired infection rates and manage the prevalence of multi-drug resistant organisms is another critical trend in healthcare facility design. Wireless communications, RFID tracking, anti-microbial surfaces, negative pressure isolation rooms, single patient rooms, and emergency department entrance alternatives are used to reduce infections, which claim up to 100,000 lives every year.
Another trend is the use of evidence-based design to assure that facilities support clinical efficiency, patient safety, and deployment of emerging information and clinical technologies.
“Hospital CEO’s face significant financial challenges. They want evidence that care environments are improving patient outcomes and workforce efficiency,” said Steven DeMello, director of research and forecasting for HealthTech.
Design research databases, modeling and simulation, virtual environments, process software, and manufacturing quality techniques (e.g. LEAN, Six Sigma) are among the tools increasingly used by hospitals and design firms, according to DeMello.
The report profiles several organizations that have successfully acted on these trends, including:
The Patrick H. Dollard Discovery Health Center in upstate New York which is saving $50,000 annually more than projected after designing the facility to become a Leadership in Energy and Environment Design certified facility;
Sutter Health’s in California and in Seattle Virginia Mason’s use of LEAN principles to design a hospital and improve process flow, respectively;
Peace Health in the Pacific Northwest participated in the Pebble Project (researching effect of facility design on quality of care and financial performance) to install patient lifts and booms, resulting in 99% fewer injuries;
Multi-state Kaiser Permanente development with a carpet manufacturer of a PVC-free carpet with the same performance as vinyl carpeting.
HealthTech (healthtech.org) is a research organization and expert network that offers its partner hospitals and health systems proprietary reports, decision support tools, and educational events for adopting care delivery innovations and deploying emerging technologies. Partners develop a competitive advantage by using HealthTech’s resources to redesign care, plan future facilities, prioritize technology investments and avoid costly errors.
Sunday, May 27, 2007
Processors called to arms in anti-biotic resistance battle
By Neil Merrett
5/25/2007- Food processing must play a role in preventing the evolutionary shifts that lead to bacterial antibiotic resistance, according to new research from the US.
Hua Wang, who is helping oversee the study at Ohio University, says that manufacturers within the food industry will have to face up to the growing dangers posed by the spread of bacterial resistance in the food chain.
"Data indicates that food could be an important avenue for antibiotic-resistant bacterial evolution and dissemination," she said, speaking at the 107th General Meeting of the American Society for Microbiology (ASM) in Toronto this week.
"The role of commensals [bacteria found normally in the gut], especially food-borne microbes, in transmitting resistance genes are becoming a concern to the scientific community," she added.
The growth in antibiotic resistance has been blamed on a process known as horizontal gene transfer, in which bacteria strains within close proximity can share genetic information, says the ASM. This shared material has been found to include coding for antibiotic resistance.
The ASM add that the process has already been identified with hospital environments, and is now being linked to food processing.
According to studies conducted last year by Hua and her colleagues, ready to eat food products carried bacteria with some form of antibiotic-resistance.
Though resistance was not linked to pathogens in processed cheese and yoghurt, it was found in a variety of products like seafood, meats, dairy and deli items.
However, the findings that horizontal gene transfer can also occur within both commensal and beneficial strains of bacteria are of particular concern for food processors and formulators.
While establishing that food processing may be aiding antibiotic resistance in bacteria, Hua suggests that it could be used to prevent further spreads.
By working with her colleagues, she hopes to establish conditions that can minimize horizontal gene transfer within the fermentation of products. It is hoped that the research could lead to breakthroughs in other types of food production.
"Given the proper investment of money, effort and time we can identify the steps that need to be taken at the processing level to minimize the emergence of antibiotic resistance genes in our food supply," says Hua.
5/25/2007- Food processing must play a role in preventing the evolutionary shifts that lead to bacterial antibiotic resistance, according to new research from the US.
Hua Wang, who is helping oversee the study at Ohio University, says that manufacturers within the food industry will have to face up to the growing dangers posed by the spread of bacterial resistance in the food chain.
"Data indicates that food could be an important avenue for antibiotic-resistant bacterial evolution and dissemination," she said, speaking at the 107th General Meeting of the American Society for Microbiology (ASM) in Toronto this week.
"The role of commensals [bacteria found normally in the gut], especially food-borne microbes, in transmitting resistance genes are becoming a concern to the scientific community," she added.
The growth in antibiotic resistance has been blamed on a process known as horizontal gene transfer, in which bacteria strains within close proximity can share genetic information, says the ASM. This shared material has been found to include coding for antibiotic resistance.
The ASM add that the process has already been identified with hospital environments, and is now being linked to food processing.
According to studies conducted last year by Hua and her colleagues, ready to eat food products carried bacteria with some form of antibiotic-resistance.
Though resistance was not linked to pathogens in processed cheese and yoghurt, it was found in a variety of products like seafood, meats, dairy and deli items.
However, the findings that horizontal gene transfer can also occur within both commensal and beneficial strains of bacteria are of particular concern for food processors and formulators.
While establishing that food processing may be aiding antibiotic resistance in bacteria, Hua suggests that it could be used to prevent further spreads.
By working with her colleagues, she hopes to establish conditions that can minimize horizontal gene transfer within the fermentation of products. It is hoped that the research could lead to breakthroughs in other types of food production.
"Given the proper investment of money, effort and time we can identify the steps that need to be taken at the processing level to minimize the emergence of antibiotic resistance genes in our food supply," says Hua.
Scientists have unveiled a new weapon which could help speed up wound healing in diabetics - water.
Slowed wound healing, mainly due to damage to small blood vessels, can be a serious complication of the condition which effects more than two million sufferers in Britain.
According to researchers a form of "super-oxidised" water can accelerate healing by killing bugs more effectively than bleach - without harming tissue.
The healing of wounds is a problem for diabetics who do not have good blood glucose control or have circulatory problems.
The key ingredient of the product called Microcyn - which was presented at biomedical business conference Global Healthcare in Monte Carlo - is electrically charged atoms called oxychlorine ions which destroy viruses, bacteria and fungi.
Wounds of diabetics treated with the product and an antibiotic healed within 43 days on average - compared with 55 days for patients given the standard treatment of iodine plus an antibiotic.
Hoji Alimi, chief executive of the California-based developers Oculus, said human cells are spared because they are tightly bound together in a matrix.
He said: "Microcyn only kills cells it can completely surround."
The vital atoms are formed by exposing purified water to sodium chloride, reports New Scientist.
These kill microbes and viruses but are present in much lower amounts than in bleach which also contains a slightly different combination of ions - including large amounts of the highly reactive hypochlorite ion.
Despite containing 300 times less hypochlorite than bleach Microcyn killed 10 strains of bleach-resistant bacteria, according to a study.
Professor Eileen Thatcher, of Sonoma State University in Rohnert Park, California, who carried out the research, said: "It may be that other unusual ions in Microcyn but not bleach are instantly lethal to bugs."
Mr Alimi has also found a way to stabilise the ions by making them react with and regenerate each other during storage so the fluid remains active for up to two years.
Microcyn was officially approved in the US for cleaning wounds two years ago but some physicians have also been using it off label to accelerate healing.
Dr Cheryl Bongiovanni, director of wound care at the Lake District Hospital in Lakeview, Oregon, has used Microcyn on around 1,000 diabetic patients with leg and foot wounds over the past 18 months.
She said: "When you spray it on you see the treated tissue 'pink up' and go beefy which is good because it means the oxygen supply has resumed."
Official phase II trials to test the product's wound-healing potential are currently taking place in the US and Europe.
Professor Andrew Boulton, of the Manchester Royal Infirmary who is conducting one such study, said: "It does seem promising. Hopefully it will confirm our initial good experience."
Tracy Kelly, care advisor at Diabetes UK, said 15 per cent of people with diabetes who develop foot ulcers eventually suffer amputations.
She said: "We would welcome any safe, effective treatment which could help hasten recovery."
Copyright © 2006 National News +44(0)207 684 3000
According to researchers a form of "super-oxidised" water can accelerate healing by killing bugs more effectively than bleach - without harming tissue.
The healing of wounds is a problem for diabetics who do not have good blood glucose control or have circulatory problems.
The key ingredient of the product called Microcyn - which was presented at biomedical business conference Global Healthcare in Monte Carlo - is electrically charged atoms called oxychlorine ions which destroy viruses, bacteria and fungi.
Wounds of diabetics treated with the product and an antibiotic healed within 43 days on average - compared with 55 days for patients given the standard treatment of iodine plus an antibiotic.
Hoji Alimi, chief executive of the California-based developers Oculus, said human cells are spared because they are tightly bound together in a matrix.
He said: "Microcyn only kills cells it can completely surround."
The vital atoms are formed by exposing purified water to sodium chloride, reports New Scientist.
These kill microbes and viruses but are present in much lower amounts than in bleach which also contains a slightly different combination of ions - including large amounts of the highly reactive hypochlorite ion.
Despite containing 300 times less hypochlorite than bleach Microcyn killed 10 strains of bleach-resistant bacteria, according to a study.
Professor Eileen Thatcher, of Sonoma State University in Rohnert Park, California, who carried out the research, said: "It may be that other unusual ions in Microcyn but not bleach are instantly lethal to bugs."
Mr Alimi has also found a way to stabilise the ions by making them react with and regenerate each other during storage so the fluid remains active for up to two years.
Microcyn was officially approved in the US for cleaning wounds two years ago but some physicians have also been using it off label to accelerate healing.
Dr Cheryl Bongiovanni, director of wound care at the Lake District Hospital in Lakeview, Oregon, has used Microcyn on around 1,000 diabetic patients with leg and foot wounds over the past 18 months.
She said: "When you spray it on you see the treated tissue 'pink up' and go beefy which is good because it means the oxygen supply has resumed."
Official phase II trials to test the product's wound-healing potential are currently taking place in the US and Europe.
Professor Andrew Boulton, of the Manchester Royal Infirmary who is conducting one such study, said: "It does seem promising. Hopefully it will confirm our initial good experience."
Tracy Kelly, care advisor at Diabetes UK, said 15 per cent of people with diabetes who develop foot ulcers eventually suffer amputations.
She said: "We would welcome any safe, effective treatment which could help hasten recovery."
Copyright © 2006 National News +44(0)207 684 3000
Friday, May 25, 2007
Resistance genes in our food supply
Could the food we eat be contributing to the continuing rise of antibiotic-resistant infections? Harmless and even beneficial bacteria that exist in our food supply may also be carrying genes that code for antibiotic resistance. Once in our bodies, could they transmit the resistance genes to disease-causing bacteria?
"The data indicate that food could be an important avenue for antibiotic-resistant bacterial evolution and dissemination. The role of commensals, especially food-borne microbes, in transmitting resistance genes are becoming a concern to the scientific community," says Hua Wang of the Ohio State University, presenting May 23, 2007 at the 107th General Meeting of the American Society for Microbiology (ASM) in Toronto.
The culprit is a process known as horizontal gene transfer, in which bacteria in close proximity to each other can share genetic information, including genes that code for antibiotic resistance. Horizontal gene transfer between disease-causing bacteria in the hospital setting has already been recognized as an important avenue for the exchange of antibiotic-resistance genes among pathogens.
Research has also already demonstrated that pathogenic bacteria have the ability to engage in horizontal gene transfer with various commensal bacteria and even beneficial bacteria, including those from the food chain. What concerns scientists is that the size and diversity of the gene pool represented by commensal bacteria increases the likelihood of gene transfer and some commensals possess high frequency gene transfer mechanisms.
"We have demonstrated not only that organisms carrying such intrinsic mechanisms have the potential to become an important reservoir for antibiotic resistance genes but, more importantly, that these intermediate organisms can disseminate antibiotic resistance genes in subsequent events much more effectively than the parental donor strain," says Hua.
"Once we no longer limit ourselves to foodborne pathogens and look at commensal bacteria, we will find that the magnitude of antibiotic-resistant bacterial contamination in the food chain is tremendous," says Hua.
In a study published last year, she and her colleagues tested a variety of ready-to-eat food samples including seafood, meats, dairy, deli items and fresh produce purchased from several grocery chain stores. With the exception of processed cheese and yogurt, antibiotic-resistance gene-carrying bacteria were found in many food samples examined.,
"Despite the fact that this study only screened for a limited number of resistance markers, it illustrated the prevalence of antibiotic-resistant commensals and antibiotic-resistance genes in retail foods," says Hua. "While further research is needed to establish the direct correlation between the antibiotic-resistant microbes from foods and the antibiotic-resistant population in host ecosystems, it is evident that a constant supply of antibiotic-resistant bacteria, partnered with occasional colonization and horizontal gene transfer, are at least partially responsible for the increased antibiotic resistance profiles seen in humans."
Antibiotic resistant infections are an increasing public health problem, says Marilyn Roberts of the University of Washington. Depending on the disease and the patient, an antibiotic-resistant infection could triple a hospital stay. A methicillin-resistant Staphylococcus aureus infection in a hospital patient can cost thousands of dollars more to treat. In some cases, such as the new extensively resistant tuberculosis, antibiotics are no longer effective, forcing doctors to take extreme measures like removing an infected lung.
The problem is not just confined to the food supply. Recent studies have shown antibiotic resistance genes in bacteria in the digestive tract of young infants. Since these children were still breast- or formula-feeding and had not eaten solid food yet, they must have acquired these genes somewhere other than the food supply. This suggests that resistance genes from the environment might have played an important role, says Hua.
"Antibiotics and the contamination of the environment is a medical problem, an agricultural problem and a human problem. Everybody plays a role in it. They also have a stake in it," says Roberts.
But there are things that can be done to minimize resistance genes in our food. Hua is currently working on characterizing the optimum conditions and processing parameters to minimize the emergence of these genes in fermented products. In time, and with a little help, she hopes to expand this research to other food industries as well.
"Given the proper investment of money, effort and time we can identify the steps that need to be taken at the processing level to minimize the emergence of antibiotic resistance genes in our food supply," says Hua.
"The data indicate that food could be an important avenue for antibiotic-resistant bacterial evolution and dissemination. The role of commensals, especially food-borne microbes, in transmitting resistance genes are becoming a concern to the scientific community," says Hua Wang of the Ohio State University, presenting May 23, 2007 at the 107th General Meeting of the American Society for Microbiology (ASM) in Toronto.
The culprit is a process known as horizontal gene transfer, in which bacteria in close proximity to each other can share genetic information, including genes that code for antibiotic resistance. Horizontal gene transfer between disease-causing bacteria in the hospital setting has already been recognized as an important avenue for the exchange of antibiotic-resistance genes among pathogens.
Research has also already demonstrated that pathogenic bacteria have the ability to engage in horizontal gene transfer with various commensal bacteria and even beneficial bacteria, including those from the food chain. What concerns scientists is that the size and diversity of the gene pool represented by commensal bacteria increases the likelihood of gene transfer and some commensals possess high frequency gene transfer mechanisms.
"We have demonstrated not only that organisms carrying such intrinsic mechanisms have the potential to become an important reservoir for antibiotic resistance genes but, more importantly, that these intermediate organisms can disseminate antibiotic resistance genes in subsequent events much more effectively than the parental donor strain," says Hua.
"Once we no longer limit ourselves to foodborne pathogens and look at commensal bacteria, we will find that the magnitude of antibiotic-resistant bacterial contamination in the food chain is tremendous," says Hua.
In a study published last year, she and her colleagues tested a variety of ready-to-eat food samples including seafood, meats, dairy, deli items and fresh produce purchased from several grocery chain stores. With the exception of processed cheese and yogurt, antibiotic-resistance gene-carrying bacteria were found in many food samples examined.,
"Despite the fact that this study only screened for a limited number of resistance markers, it illustrated the prevalence of antibiotic-resistant commensals and antibiotic-resistance genes in retail foods," says Hua. "While further research is needed to establish the direct correlation between the antibiotic-resistant microbes from foods and the antibiotic-resistant population in host ecosystems, it is evident that a constant supply of antibiotic-resistant bacteria, partnered with occasional colonization and horizontal gene transfer, are at least partially responsible for the increased antibiotic resistance profiles seen in humans."
Antibiotic resistant infections are an increasing public health problem, says Marilyn Roberts of the University of Washington. Depending on the disease and the patient, an antibiotic-resistant infection could triple a hospital stay. A methicillin-resistant Staphylococcus aureus infection in a hospital patient can cost thousands of dollars more to treat. In some cases, such as the new extensively resistant tuberculosis, antibiotics are no longer effective, forcing doctors to take extreme measures like removing an infected lung.
The problem is not just confined to the food supply. Recent studies have shown antibiotic resistance genes in bacteria in the digestive tract of young infants. Since these children were still breast- or formula-feeding and had not eaten solid food yet, they must have acquired these genes somewhere other than the food supply. This suggests that resistance genes from the environment might have played an important role, says Hua.
"Antibiotics and the contamination of the environment is a medical problem, an agricultural problem and a human problem. Everybody plays a role in it. They also have a stake in it," says Roberts.
But there are things that can be done to minimize resistance genes in our food. Hua is currently working on characterizing the optimum conditions and processing parameters to minimize the emergence of these genes in fermented products. In time, and with a little help, she hopes to expand this research to other food industries as well.
"Given the proper investment of money, effort and time we can identify the steps that need to be taken at the processing level to minimize the emergence of antibiotic resistance genes in our food supply," says Hua.
Tuesday, May 8, 2007
Defenceless against a tiny bug
Andrew Pollack
The E.coli still has the last laugh.Despite many approaches, prevention still seems the best way out of a deadly infection.
Shousun C. Szu, a scientist at the National Institutes of Health, says the best way to prevent people from being poisoned by deadly E. coli would be to vaccinate all infants against the bacteria. Graeme McRae, a Canadian biotechnology executive, says it would be more practical to inoculate cows instead. Vaccines for people and for cattle are just two approaches under development to prevent or treat food poisoning by the strain E. coli O157:H7.
Right now, scientists can do little medically to fight the pathogen, which was responsible for two severe outbreaks in the US. The main approach has been to try to prevent contamination through careful handling of food, rigorous inspections and government regulation. Slaughterhouses have already sharply reduced contamination through practices like washing carcasses with hot water, steam or acids. Now the focus is on new procedures and regulations for the fresh-produce industry. On the animal side, a vaccine for cattle developed by McRae’s company, Bioniche Life Sciences, was approved in December for distribution to veterinarians in Canada. Studies have shown that the vaccine can reduce but not eliminate the E. coli shed into manure. Not only does that make the cows cleaner as they go into the slaughterhouse, but it could also conceivably reduce the risk that the germ will spread from a feedlot to a nearby produce field though water or wild animals. Cows and their manure are considered the major sources of the pathogen. “If we can reduce the likelihood that animals are going to carry the bacteria, then we might reduce over time what they put out into the environment,” said Guy Loneragan, a veterinary epidemiologist at West Texas A&M University. Other methods being tested include cattle antibiotics, an industrial chemical, bacterial-killing viruses and friendly bacteria to displace the evil ones. Efforts to develop drugs and vaccines for people also face barriers. Because outbreaks are rare and sporadic, for instance, it would be difficult to test such treatments in clinical trials. E. coli O157:H7 causes 75,000 cases of infection and 61 deaths in the United States each year, according to a 1999 estimate by the Centers for Disease Control and Prevention posted on its Web site. Dr. Phillip I. Tarr, an expert at Washington University in St. Louis, says treatment is difficult because the bloody diarrhea that signals infection may not occur until three to four days after ingestion of the bacteria. By then, a patient could be well on the way to kidney failure. Antibiotics, the usual treatment for bacterial infection, only make things worse by killing the bacteria and releasing more of their toxin, Tarr said. He added that the sole treatment shown to reduce the severity of kidney problems was intravenous fluids. Other scientists are trying. Thallion Pharmaceuticals of Montreal and Teijin Pharma of Japan have separately developed monoclonal antibodies that can latch on to the toxin molecules and neutralize them. Monoclonal antibodies, a synthetic version of the body's own infection fighters, are commonly used to treat cancer and other diseases. Thallion and Teijin have shown that the antibodies can protect laboratory animals from lethal doses and have conducted preliminary safety testing in people. But at the recent FDA advisory committee meeting, both said it would be prohibitively expensive to test whether their drugs could prevent hemolytic uremic syndrome. Some outside scientists question whether a treatment that starts after the toxin is already in the bloodstream would be effective. One approach already in use is probiotics, the idea that friendly bacteria fed to cattle will displace O157. The Nutrition Physiology Corp. of Guymon, Okla., sells a feed additive with lactobacillus, the same type of bacterium used in yogurt. The additive is sold to aid cattle digestion, but some studies suggest that it also reduces O157 in manure. An experimental approach is to feed cows sodium chlorate, a chemical used in the pulp and paper industry. This idea takes advantage of the fact that O157 has an enzyme that allows it to survive without oxygen, which is not true for most desirable bacteria. That enzyme will convert sodium chlorate to sodium chlorite, which poisons the pathogen. “It’s like a suicide pill to the E. coli,” said Robin C. Anderson, a microbiologist for the Agriculture Department in College Station, Texas. Anderson said the treatment did not harm the cow. The antibiotic neomycin has also been shown to reduce O157 levels in manure. Using antibiotics in animals raises concerns of spurring development of human pathogens resistant to the medicines. Another approach being studied involves phages, viruses that infect and kill bacteria. Experts say multiple approaches might be used in parallel, because no single approach works perfectly. Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said: “What really is a concern to me about this issue is we always have a tendency to want high-tech responses to what in many cases are common-sense low-tech solutions,” Osterholm said. In any case, even if a high-tech solution was desired, there does not seem to be a vaccine for spinach as there is for cattle. Greens are now often rinsed in chlorine solution, but that is not always effective because surface nooks and crannies can shelter the bacteria, said James Gorney, senior vice president for food safety and technology at the United Fresh Produce Association, a trade group. A possible alternative is to use a gas like chlorine dioxide instead of a liquid wash, Gorney said. Irradiation can also kill the bacteria. But he said the amount of radiation needed could damage fruits or vegetables. And some consumers object to the technique. “Any one of these technologies doesn't offer us a pasteurization step," Gorney said. "So we are left with prevention, prevention and prevention, preventing the contamination from ever occurring.” Szu of the health institutes and colleagues have developed a vaccine made of the complex sugar that is on the surface of the bacteria, the very O-type polysaccharide that gives O157 its name. The sugar is linked to a protein taken from another bacterium to make it more potent in stimulating the immune system. Szu and collaborators have tested the vaccine on adult volunteers and on children 2 to 5 years old. The volunteers were not exposed to O157 -- that would be unethical -- but they developed antibodies to it. Moreover, when the bacteria were exposed in the laboratory to blood samples from vaccinated people, the microbes were killed. Szu said the next test would be in infants. The vaccine is years from the market. As with drugs, testing effectiveness would be difficult, and some experts say it may not make sense to vaccinate every child to protect a small number. The cattle vaccine developed by Bioniche is based on the work of B. Brett Finlay of the University of British Columbia, who helped discover how O157 bacteria attach themselves to the cattle intestines, where they can then multiply. The bacteria use a type of microscopic syringe to shoot proteins into the cells lining the intestine, and the cells erect a protein pedestal, to which the bacteria can bind. The Bioniche vaccine consists of proteins involved in the attachment. The idea is that the cow's immune system would make antibodies to attack the proteins, thereby blocking the attachment. The bacteria could still pass through the cow and into manure. But if they could not colonize, their levels should remain low. Tests at the University of Nebraska found that the vaccine reduced by 70 percent the number of cows shedding O157 into their manure, said Rodney A. Moxley, a professor of veterinary science there. As few as 10 bacteria can make someone ill. The bacteria release one or two potent toxins that cause bloody diarrhea. In 15 percent of children younger than 10, and more rarely for adults, the infection causes hemolytic uremic syndrome, in which red blood cells are destroyed and the kidneys fail. In a small percentage of such cases, the syndrome proves fatal. NYT News Service
The E.coli still has the last laugh.Despite many approaches, prevention still seems the best way out of a deadly infection.
Shousun C. Szu, a scientist at the National Institutes of Health, says the best way to prevent people from being poisoned by deadly E. coli would be to vaccinate all infants against the bacteria. Graeme McRae, a Canadian biotechnology executive, says it would be more practical to inoculate cows instead. Vaccines for people and for cattle are just two approaches under development to prevent or treat food poisoning by the strain E. coli O157:H7.
Right now, scientists can do little medically to fight the pathogen, which was responsible for two severe outbreaks in the US. The main approach has been to try to prevent contamination through careful handling of food, rigorous inspections and government regulation. Slaughterhouses have already sharply reduced contamination through practices like washing carcasses with hot water, steam or acids. Now the focus is on new procedures and regulations for the fresh-produce industry. On the animal side, a vaccine for cattle developed by McRae’s company, Bioniche Life Sciences, was approved in December for distribution to veterinarians in Canada. Studies have shown that the vaccine can reduce but not eliminate the E. coli shed into manure. Not only does that make the cows cleaner as they go into the slaughterhouse, but it could also conceivably reduce the risk that the germ will spread from a feedlot to a nearby produce field though water or wild animals. Cows and their manure are considered the major sources of the pathogen. “If we can reduce the likelihood that animals are going to carry the bacteria, then we might reduce over time what they put out into the environment,” said Guy Loneragan, a veterinary epidemiologist at West Texas A&M University. Other methods being tested include cattle antibiotics, an industrial chemical, bacterial-killing viruses and friendly bacteria to displace the evil ones. Efforts to develop drugs and vaccines for people also face barriers. Because outbreaks are rare and sporadic, for instance, it would be difficult to test such treatments in clinical trials. E. coli O157:H7 causes 75,000 cases of infection and 61 deaths in the United States each year, according to a 1999 estimate by the Centers for Disease Control and Prevention posted on its Web site. Dr. Phillip I. Tarr, an expert at Washington University in St. Louis, says treatment is difficult because the bloody diarrhea that signals infection may not occur until three to four days after ingestion of the bacteria. By then, a patient could be well on the way to kidney failure. Antibiotics, the usual treatment for bacterial infection, only make things worse by killing the bacteria and releasing more of their toxin, Tarr said. He added that the sole treatment shown to reduce the severity of kidney problems was intravenous fluids. Other scientists are trying. Thallion Pharmaceuticals of Montreal and Teijin Pharma of Japan have separately developed monoclonal antibodies that can latch on to the toxin molecules and neutralize them. Monoclonal antibodies, a synthetic version of the body's own infection fighters, are commonly used to treat cancer and other diseases. Thallion and Teijin have shown that the antibodies can protect laboratory animals from lethal doses and have conducted preliminary safety testing in people. But at the recent FDA advisory committee meeting, both said it would be prohibitively expensive to test whether their drugs could prevent hemolytic uremic syndrome. Some outside scientists question whether a treatment that starts after the toxin is already in the bloodstream would be effective. One approach already in use is probiotics, the idea that friendly bacteria fed to cattle will displace O157. The Nutrition Physiology Corp. of Guymon, Okla., sells a feed additive with lactobacillus, the same type of bacterium used in yogurt. The additive is sold to aid cattle digestion, but some studies suggest that it also reduces O157 in manure. An experimental approach is to feed cows sodium chlorate, a chemical used in the pulp and paper industry. This idea takes advantage of the fact that O157 has an enzyme that allows it to survive without oxygen, which is not true for most desirable bacteria. That enzyme will convert sodium chlorate to sodium chlorite, which poisons the pathogen. “It’s like a suicide pill to the E. coli,” said Robin C. Anderson, a microbiologist for the Agriculture Department in College Station, Texas. Anderson said the treatment did not harm the cow. The antibiotic neomycin has also been shown to reduce O157 levels in manure. Using antibiotics in animals raises concerns of spurring development of human pathogens resistant to the medicines. Another approach being studied involves phages, viruses that infect and kill bacteria. Experts say multiple approaches might be used in parallel, because no single approach works perfectly. Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said: “What really is a concern to me about this issue is we always have a tendency to want high-tech responses to what in many cases are common-sense low-tech solutions,” Osterholm said. In any case, even if a high-tech solution was desired, there does not seem to be a vaccine for spinach as there is for cattle. Greens are now often rinsed in chlorine solution, but that is not always effective because surface nooks and crannies can shelter the bacteria, said James Gorney, senior vice president for food safety and technology at the United Fresh Produce Association, a trade group. A possible alternative is to use a gas like chlorine dioxide instead of a liquid wash, Gorney said. Irradiation can also kill the bacteria. But he said the amount of radiation needed could damage fruits or vegetables. And some consumers object to the technique. “Any one of these technologies doesn't offer us a pasteurization step," Gorney said. "So we are left with prevention, prevention and prevention, preventing the contamination from ever occurring.” Szu of the health institutes and colleagues have developed a vaccine made of the complex sugar that is on the surface of the bacteria, the very O-type polysaccharide that gives O157 its name. The sugar is linked to a protein taken from another bacterium to make it more potent in stimulating the immune system. Szu and collaborators have tested the vaccine on adult volunteers and on children 2 to 5 years old. The volunteers were not exposed to O157 -- that would be unethical -- but they developed antibodies to it. Moreover, when the bacteria were exposed in the laboratory to blood samples from vaccinated people, the microbes were killed. Szu said the next test would be in infants. The vaccine is years from the market. As with drugs, testing effectiveness would be difficult, and some experts say it may not make sense to vaccinate every child to protect a small number. The cattle vaccine developed by Bioniche is based on the work of B. Brett Finlay of the University of British Columbia, who helped discover how O157 bacteria attach themselves to the cattle intestines, where they can then multiply. The bacteria use a type of microscopic syringe to shoot proteins into the cells lining the intestine, and the cells erect a protein pedestal, to which the bacteria can bind. The Bioniche vaccine consists of proteins involved in the attachment. The idea is that the cow's immune system would make antibodies to attack the proteins, thereby blocking the attachment. The bacteria could still pass through the cow and into manure. But if they could not colonize, their levels should remain low. Tests at the University of Nebraska found that the vaccine reduced by 70 percent the number of cows shedding O157 into their manure, said Rodney A. Moxley, a professor of veterinary science there. As few as 10 bacteria can make someone ill. The bacteria release one or two potent toxins that cause bloody diarrhea. In 15 percent of children younger than 10, and more rarely for adults, the infection causes hemolytic uremic syndrome, in which red blood cells are destroyed and the kidneys fail. In a small percentage of such cases, the syndrome proves fatal. NYT News Service
Saturday, May 5, 2007
New Approach Could Lower Antibiotic Requirements By 50 Times
Antibiotic doses could be reduced by up to 50 times using a new approach based on bacteriophages.
Steven Hagens, previously at the University of Vienna, told Chemistry & Industry, the magazine of the SCI, that certain bacteriophages, a type of virus that infects bacteria, can boost the effectiveness of antibiotics gentamicin, gramacidin or tetracycline.
It is the phages' ability to channel through bacterial cell membranes that boosts antibiotic effectiveness. 'Pseudomonas bacteria for example are particularly multi-resistant to antibiotics because they have efflux pump mechanisms that enable them to throw out antibiotics. A pore in the cell wall would obviously cancel the efflux effect,' Hagens explains.
Pseudomonas bacteria cause pneumonia and are a common cause of hospital-acquired infections.
Experiments in mice revealed that 75% of those infected with a lethal dose of Pseudomonas survived if the antibiotic gentamicin was administered in the presence of bacteriophages. None survived without the phages (Microb. Drug Resist., 2006, 12 (3), 164).
The bacteriophage approach would also be particularly useful for treating cases of food poisoning, because the lower doses of antibiotic needed would not disrupt the friendly bacteria in the gut - a big problem with conventional antibiotic treatments.
'The prospect of using such treatments to prolong the life of existing agents and delay the onset of widespread resistance is to be welcomed,' said Jim Spencer a lecturer in microbial pathogenesis at the University of Bristol.
The overuse of antibiotics since the 1940s had slowly created a host of infections that are resistant to antibiotics. MRSA (Methicillin-resistant Staphylococcus aureus) for example is rapidly spreading through hospitals, affecting more than 8,000 people in the UK every year. MRSA infection can lead to septic shock and death.
Note: This story has been adapted from a news release issued by Society of Chemical Industry.
Steven Hagens, previously at the University of Vienna, told Chemistry & Industry, the magazine of the SCI, that certain bacteriophages, a type of virus that infects bacteria, can boost the effectiveness of antibiotics gentamicin, gramacidin or tetracycline.
It is the phages' ability to channel through bacterial cell membranes that boosts antibiotic effectiveness. 'Pseudomonas bacteria for example are particularly multi-resistant to antibiotics because they have efflux pump mechanisms that enable them to throw out antibiotics. A pore in the cell wall would obviously cancel the efflux effect,' Hagens explains.
Pseudomonas bacteria cause pneumonia and are a common cause of hospital-acquired infections.
Experiments in mice revealed that 75% of those infected with a lethal dose of Pseudomonas survived if the antibiotic gentamicin was administered in the presence of bacteriophages. None survived without the phages (Microb. Drug Resist., 2006, 12 (3), 164).
The bacteriophage approach would also be particularly useful for treating cases of food poisoning, because the lower doses of antibiotic needed would not disrupt the friendly bacteria in the gut - a big problem with conventional antibiotic treatments.
'The prospect of using such treatments to prolong the life of existing agents and delay the onset of widespread resistance is to be welcomed,' said Jim Spencer a lecturer in microbial pathogenesis at the University of Bristol.
The overuse of antibiotics since the 1940s had slowly created a host of infections that are resistant to antibiotics. MRSA (Methicillin-resistant Staphylococcus aureus) for example is rapidly spreading through hospitals, affecting more than 8,000 people in the UK every year. MRSA infection can lead to septic shock and death.
Note: This story has been adapted from a news release issued by Society of Chemical Industry.
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