Sep. 18, 2008) — Vital components of modern medicine such as major surgery, organ transplantation, and cancer chemotherapy will be threatened if antibiotic resistance is not tackled urgently, warn experts on bmj.com.
A concerted global response is needed to address rising rates of bacterial resistance caused by the use and abuse of antibiotics or "we will return to the pre-antibiotic era", write Professor Otto Cars and colleagues in an editorial.
All antibiotic use "uses up" some of the effectiveness of that antibiotic, diminishing the ability to use it in the future, write the authors, and antibiotics can no longer be considered as a renewable source.
They point out that existing antibiotics are losing their effect at an alarming pace, while the development of new antibiotics is declining. More than a dozen new classes of antibiotics were developed between 1930 and 1970, but only two new classes have been developed since then.
According to the European Centre for Disease Prevention and Control, the most important disease threat in Europe is from micro-organisms that have become resistant to antibiotics. As far back as 2000, the World Health Organisation was calling for a massive effort to address the problem of antimicrobial resistance to prevent the "health catastrophe of tomorrow".
So why has so little been done to address the problem of resistance, ask the authors?
Antibiotics are over prescribed, still illegally sold over the counter in some EU countries, and self medication with leftover medicines is commonplace.
There are alarming reports about serious consequences of antibiotic resistance from all around the world. However, there is still a dearth of data on the magnitude and burden of antibiotic resistance, or its economic impact on individuals, health care, and society. This, they suggest, may explain why there has been little response to this public health threat from politicians, public health workers, and consumers.
In addition, there are significant scientific challenges but few incentives to developing new antibiotics, state the authors.
The authors believe that priority must be given to the most urgently needed antibiotics and incentives given for developing antibacterials with new mechanisms of action. In addition, "the use of new antibiotics must be safeguarded by regulations and practices that ensure rational use, to avoid repeating the mistakes we have made by overusing the old ones", they say.
They point out that reducing consumer demand could be the strongest force to driving change—individuals must be educated to understand that their choice to use an antibiotic will affect the possibility of effectively treating bacterial infections in other people.
But, they claim, the ultimate responsibility for coordination and resources rests with national governments, WHO and other international stakeholders.
Not only is there an urgent need for up-to-date information on the level of antibiotic resistance, but also for evidence of effective interventions for the prevention and control of antibiotic resistance at national and local levels, while more focus is needed on infectious diseases, they conclude.
--------------------------------------------------------------------------------
Adapted from materials provided by BMJ-British Medical Journal, via EurekAlert!, a service of AAAS.
Source: ScienceDaily
Showing posts with label antibiotics. Show all posts
Showing posts with label antibiotics. Show all posts
Saturday, September 27, 2008
Sunday, August 24, 2008
New antibiotic beats superbugs at their own game
The problem with antibiotics is that, eventually, bacteria outsmart them and become resistant. But by targeting the gene that confers such resistance, a new drug may be able to finally outwit them. Rockefeller University scientists tested the new drug, called Ceftobiprole, against some of the deadliest strains of multidrug-resistant Staphylococcus aureus (MRSA) bacteria, which are responsible for the great majority of staphylococcal infections worldwide, both in hospitals and in the community.
The research, to be published in the August 2008 issue of the journal Antimicrobial Agents and Chemotherapy and available online now, looked at how well Ceftobiprole worked against bacterial clones that had already developed resistance to other drugs. In every case, Ceftobiprole won. "It just knocked out the cells 100 percent," says the study's lead investigator, Alexander Tomasz, head of the Laboratory of Microbiology at Rockefeller.
Previous research had already shown that -- in general -- Ceftobiprole was highly effective against most clinical isolates of S. aureus. "Instead, we looked more carefully at the highly resistant cells that already occur in such clinical isolates at very low frequency -- maybe in one bacterium in every 1,000," says Tomasz. Ceftobiprole was able to kill these resistant cells.
Never before has an antibiotic been tested this way. "In the history of antibiotic development, an antibiotic arrives on the scene, and sooner or later resistant bacteria emerge," Tomasz says. "We sought to test in advance which would win this particular chess game: the new drug, or the bacteria that now cause human deaths."
In an ominous new "move" in this chess game, S. aureus strains with resistance to vancomycin (VRSA), a different class of antibiotics, also began to appear in hospitals in the United States. Ceftobiprole was also able to kill these new resistant VRSA strains.
The drug is effective because the chemists who developed Ceftobiprole managed to outwit the bacteria at their own game, Tomasz says. The broad-spectrum antibiotic was discovered by Basilea Pharmaceuticals, based in Basel, Switzerland, and is being developed in the U.S. and worldwide by Johnson & Johnson. The research was supported by Johnson & Johnson along with a grant from the U.S. Public Health Service.
Source : Rockefeller University
The research, to be published in the August 2008 issue of the journal Antimicrobial Agents and Chemotherapy and available online now, looked at how well Ceftobiprole worked against bacterial clones that had already developed resistance to other drugs. In every case, Ceftobiprole won. "It just knocked out the cells 100 percent," says the study's lead investigator, Alexander Tomasz, head of the Laboratory of Microbiology at Rockefeller.
Previous research had already shown that -- in general -- Ceftobiprole was highly effective against most clinical isolates of S. aureus. "Instead, we looked more carefully at the highly resistant cells that already occur in such clinical isolates at very low frequency -- maybe in one bacterium in every 1,000," says Tomasz. Ceftobiprole was able to kill these resistant cells.
Never before has an antibiotic been tested this way. "In the history of antibiotic development, an antibiotic arrives on the scene, and sooner or later resistant bacteria emerge," Tomasz says. "We sought to test in advance which would win this particular chess game: the new drug, or the bacteria that now cause human deaths."
In an ominous new "move" in this chess game, S. aureus strains with resistance to vancomycin (VRSA), a different class of antibiotics, also began to appear in hospitals in the United States. Ceftobiprole was also able to kill these new resistant VRSA strains.
The drug is effective because the chemists who developed Ceftobiprole managed to outwit the bacteria at their own game, Tomasz says. The broad-spectrum antibiotic was discovered by Basilea Pharmaceuticals, based in Basel, Switzerland, and is being developed in the U.S. and worldwide by Johnson & Johnson. The research was supported by Johnson & Johnson along with a grant from the U.S. Public Health Service.
Source : Rockefeller University
Thursday, August 21, 2008
MicuRx Pharmaceuticals Selects Next-Generation Antibiotic Candidate Targeting MRSA and Expands Operation in China
MicuRx Pharmaceuticals, Inc., a privately-held biopharmaceutical company developing next-generation antibiotics, today announced the nomination of MRX- I as its first preclinical development candidate. MRX-I is an antibacterial molecule targeting multi-drug resistant gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Simultaneously, the company expanded its operations in China to increase MicuRx' capacity in antibacterial drug discovery and development.
"Only 12 months after initial funding, we have discovered multiple drug leads and selected our first development candidate MRX-I, a promising antibacterial compound that we expect to be superior to many of the top- selling antibiotics available today," said Zhengyu Yuan, Ph.D., president and chief executive officer of MicuRx Pharmaceuticals, Inc. "This enhanced productivity is owed in part to our hybrid business model that leverages the drug discovery capacity readily available in China and the superior management expertise in the United States."
"MRX-I and additional MicuRx pipeline leads have been identified using our proprietary drug discovery platform," commented Mike F. Gordeev, Ph.D., executive vice president and chief scientific officer of MicuRx. "We will continue to leverage this novel platform to further enhance the pharmacological properties and safety profile of clinically validated antibiotic classes, creating best-in-class antibiotics capable of addressing the growing problem of the bacterial multi-drug resistance."
MicuRx raised $10 million in 2007 with Morningside Group as the sole investor. To facilitate the development of its lead compounds and expand the research capacity, MicuRx recently moved its research and development operations in China to a new 10,000 square-foot facility in ZhangJian HighTech Park in Shanghai, China. The company intends to use this integrated state-of- art chemistry and biology facility for drug discovery and development activities to advance its next-generation antimicrobial products.
About Multi-Drug Resistance and MRSA
Modern antimicrobials (antibiotics and related pharmaceuticals) have substantially reduced the threat posed by infectious diseases and contributed to a dramatic drop in mortality rates over the past 30 years. However, due to widespread use of existing drugs in the community and hospital environment, pathogenic bacteria resistant to current antimicrobial therapies have evolved and become ubiquitous, presenting a global health threat. The World Health Organization has set forth a mandate to combat this growing problem and encouraged an urgent action of the member countries. MicuRx is addressing this need directly by developing best-in-class antimicrobials targeting multi- drug resistant bacteria.
About MicuRx Pharmaceuticals, Inc.
MicuRx is discovering and developing next-generation antibacterial and antifungal products. By applying designer modifications to validated antibiotics, MicuRx intends to improve overall pharmacological properties of antimicrobial drugs in order to overcome antibiotic resistance, increase the antibacterial spectrum, improve the dosing regimen, or reduce adverse side effects. The company has research and development facilities in San Francisco Bay Area and ZhangJiang High-Tech Park in Shanghai, China.
CONTACT: Zhengyu Yuan, Ph.D., President and CEO of MicuRx Pharmaceuticals,Inc., +1-510-324-8662, ; or Angela Bitting,+1-925-202-6211, , for MicuRx Pharmaceuticals, Inc. zyuan@micurx.com a.bitting@comcast.net
"Only 12 months after initial funding, we have discovered multiple drug leads and selected our first development candidate MRX-I, a promising antibacterial compound that we expect to be superior to many of the top- selling antibiotics available today," said Zhengyu Yuan, Ph.D., president and chief executive officer of MicuRx Pharmaceuticals, Inc. "This enhanced productivity is owed in part to our hybrid business model that leverages the drug discovery capacity readily available in China and the superior management expertise in the United States."
"MRX-I and additional MicuRx pipeline leads have been identified using our proprietary drug discovery platform," commented Mike F. Gordeev, Ph.D., executive vice president and chief scientific officer of MicuRx. "We will continue to leverage this novel platform to further enhance the pharmacological properties and safety profile of clinically validated antibiotic classes, creating best-in-class antibiotics capable of addressing the growing problem of the bacterial multi-drug resistance."
MicuRx raised $10 million in 2007 with Morningside Group as the sole investor. To facilitate the development of its lead compounds and expand the research capacity, MicuRx recently moved its research and development operations in China to a new 10,000 square-foot facility in ZhangJian HighTech Park in Shanghai, China. The company intends to use this integrated state-of- art chemistry and biology facility for drug discovery and development activities to advance its next-generation antimicrobial products.
About Multi-Drug Resistance and MRSA
Modern antimicrobials (antibiotics and related pharmaceuticals) have substantially reduced the threat posed by infectious diseases and contributed to a dramatic drop in mortality rates over the past 30 years. However, due to widespread use of existing drugs in the community and hospital environment, pathogenic bacteria resistant to current antimicrobial therapies have evolved and become ubiquitous, presenting a global health threat. The World Health Organization has set forth a mandate to combat this growing problem and encouraged an urgent action of the member countries. MicuRx is addressing this need directly by developing best-in-class antimicrobials targeting multi- drug resistant bacteria.
About MicuRx Pharmaceuticals, Inc.
MicuRx is discovering and developing next-generation antibacterial and antifungal products. By applying designer modifications to validated antibiotics, MicuRx intends to improve overall pharmacological properties of antimicrobial drugs in order to overcome antibiotic resistance, increase the antibacterial spectrum, improve the dosing regimen, or reduce adverse side effects. The company has research and development facilities in San Francisco Bay Area and ZhangJiang High-Tech Park in Shanghai, China.
CONTACT: Zhengyu Yuan, Ph.D., President and CEO of MicuRx Pharmaceuticals,Inc., +1-510-324-8662, ; or Angela Bitting,+1-925-202-6211, , for MicuRx Pharmaceuticals, Inc. zyuan@micurx.com a.bitting@comcast.net
Friday, December 14, 2007
Manure Management Reduces Levels Of Antibiotics And Antibiotic Resistance Genes
ScienceDaily (Dec. 3, 2007) — Antibiotic resistance is a growing human health concern. Researchers around the globe have found antibiotics and other pharmaceuticals to be present in surface waters and sediments, municipal wastewater, animal manure lagoons, and underlying groundwater. Researchers at Colorado State University (CSU) describe a study to find out if animal waste contributes to the spread of antibiotics and antibiotic resistance genes (ARG), and if they can be reduced by appropriate manure management practices.
In the study researchers investigated the effects of manure management on the levels of antibiotics and ARG in manures. The study was conducted at two scales. In the pilot-scale experiment, horse manure was spiked with the antibiotics chlortetracycline, tylosin, and monensin and compared to horse manure that was not spiked with antibiotics to determine the response of ARG in unacclimated manures. In the large-scale experiment, dairy manure and beef feedlot manure, which were already acclimated to antibiotics, were monitored over time.
The manures were subjected to high-intensity management (HIM-amending with leaves and alfalfa, watering, and turning) and low-intensity management (LIM-no amending, watering, and turning) for six months. During this time, the levels of antibiotics were monitored using high-performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). In addition, two types of ARG that confer resistance to tetracycline, tet(W) and tet(O), were monitored using quantitative polymerase chain reaction (Q-PCR).
In the pilot study, chlortetracycline, tylosin, and monensin all dissipated more rapidly in the HIM-manure than in the LIM-manure. In the large-scale study, feedlot manure initially had higher concentrations of the several tetracycline antibiotics than the dairy manure. After four months of treatment, tet(W) and tet(O) decreased significantly in dairy manure, but two more months of treatment were necessary for similar reductions of ARG in the feedlot manures.
The results showed that HIM was more effective than LIM at increasing the rate of antibiotic dissipation, but it was not a significant factor in reducing the levels of ARG. The length of treatment time was the main factor in reducing the levels of both antibiotics and ARG. For manures with initially high levels of antibiotics, treatment times of at least six months may be necessary for a significant reduction in levels of antibiotics and ARG. The results also provided evidence that ARG may be present for extended time periods even after antibiotics have fully dissipated.
Scientists at Colorado State University are continuing research in this area by examining full-scale local on-farm waste management practices. Together this research will lead to a better understanding of possible ARG mitigation strategies so that best management practices can be developed to reduce the effects that animal waste may have on the spread of ARG.
This research was published in the November-December issue of Journal of Environmental Quality. Funding was provided by the USDA Agricultural Experiment Station at CSU and the National Science Foundation (NSF).
Adapted from materials provided by American Society of Agronomy.
In the study researchers investigated the effects of manure management on the levels of antibiotics and ARG in manures. The study was conducted at two scales. In the pilot-scale experiment, horse manure was spiked with the antibiotics chlortetracycline, tylosin, and monensin and compared to horse manure that was not spiked with antibiotics to determine the response of ARG in unacclimated manures. In the large-scale experiment, dairy manure and beef feedlot manure, which were already acclimated to antibiotics, were monitored over time.
The manures were subjected to high-intensity management (HIM-amending with leaves and alfalfa, watering, and turning) and low-intensity management (LIM-no amending, watering, and turning) for six months. During this time, the levels of antibiotics were monitored using high-performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). In addition, two types of ARG that confer resistance to tetracycline, tet(W) and tet(O), were monitored using quantitative polymerase chain reaction (Q-PCR).
In the pilot study, chlortetracycline, tylosin, and monensin all dissipated more rapidly in the HIM-manure than in the LIM-manure. In the large-scale study, feedlot manure initially had higher concentrations of the several tetracycline antibiotics than the dairy manure. After four months of treatment, tet(W) and tet(O) decreased significantly in dairy manure, but two more months of treatment were necessary for similar reductions of ARG in the feedlot manures.
The results showed that HIM was more effective than LIM at increasing the rate of antibiotic dissipation, but it was not a significant factor in reducing the levels of ARG. The length of treatment time was the main factor in reducing the levels of both antibiotics and ARG. For manures with initially high levels of antibiotics, treatment times of at least six months may be necessary for a significant reduction in levels of antibiotics and ARG. The results also provided evidence that ARG may be present for extended time periods even after antibiotics have fully dissipated.
Scientists at Colorado State University are continuing research in this area by examining full-scale local on-farm waste management practices. Together this research will lead to a better understanding of possible ARG mitigation strategies so that best management practices can be developed to reduce the effects that animal waste may have on the spread of ARG.
This research was published in the November-December issue of Journal of Environmental Quality. Funding was provided by the USDA Agricultural Experiment Station at CSU and the National Science Foundation (NSF).
Adapted from materials provided by American Society of Agronomy.
Monday, June 18, 2007
Antibiotics in failing health
By Karen Augé
Denver Post Staff Writer
The Denver Post
The last time a new tuberculosis drug was developed, Richard Nixon was in the White House and Dr. Michael Iseman was a young resident in a New York City hospital.
That drug, Rifampin, "was the biggest thing to hit TB in 30 years," said Iseman, now a doctor at National Jewish Medical and Research Center in Denver.
Since then, Iseman has become a recognized authority on TB and Rifampin has remained the centerpiece of TB treatment.
Now, however, a growing number of tuberculosis strains are not fazed by the drug - as in the highly publicized case of Andrew Speaker, who is being treated at National Jewish.
Tuberculosis isn't the only infection increasingly impervious to the antibiotics in medicine's arsenal.
In the past decade, federal agencies - such as the Centers for Disease Control and Prevention, the National Institutes of Health, and the Food and Drug Administration - have warned that antibiotic overuse has led to evolving drug-resistant bacteria.
At the same time, the agencies say, there is a dearth of research dollars for new antibiotics - creating a looming medical crisis.
"Infections that were once easily curable with antibiotics are becoming difficult, even impossible, to treat," the Infectious Disease Society of America warned in its report "Bad Bugs, No Drugs."
"The problem is dollars, not chemistry," said Christopher Spivey, a spokesman for the Boston-based Alliance for the Prudent Use of Antibiotics.
Antibiotics not as profitable
Antibiotic development requires huge investments of money, $400 million to $800 million, according to a study in the journal Clinical Infectious Diseases.
To provide as much income as drug companies get from the sale of one drug to a person who, for example, takes a weight-loss pill daily, a company would have to sell antibiotics to 200 to 500 people with an illness like pneumonia, Spivey said.
There are currently under development 50 drugs each for obesity, pain and Type II diabetes, according to PhRMA, a group representing the nation's leading drugmakers.
There are just nine new drugs in the works for tuberculosis and eight for malaria.
For staph infections and drug- resistant staph infections, PhRMA lists 23 drugs under development.
This isn't a new trend. FDA approval of new anti-bacterial drugs has dropped 56 percent in 20 years, according to a 2004 study by Brad Spellberg, a professor of medicine at the University of California, Los Angeles.
Work on new TB drugs has languished in part because of the widespread, mistaken belief that the disease was no longer a problem in this country, said Mel Spigelman, director of research and development for the Global Alliance for TB Drug Development.
Iseman said that on the world market drugmakers are discouraged from developing antibiotics.
"There is a tendency - in global use - for knock-offs," Iseman said. "Companies simply choose not to honor patent protections and it's done under the seemingly noble rubric of, 'we have patients dying of - whatever disease - in our country and we can't afford your drug, so we're going to make our own.' "
In its report, the infectious-disease society recommended incentives, such as tax breaks, for antibiotic research and development.
Difficult to draw attention
Still, drug companies don't get much public sympathy these days, which could make it politically tough for members of Congress to grant those tax breaks, Iseman said.
Antibiotic development "won't get on the radar until there is a really good killing plague," Spivey said.
In that respect, Speaker may have unintentionally done a favor for TB drug research by drawing attention to the disease, Spivey said.
Since 2000, interest in TB has picked up, said the TB Alliance's Spigelman.
While only a handful of new TB drugs are in the pipeline, even that is progress, Spigelman said.
"In 2000, we had zero," he said.
This year, the National Institutes of Health will spend $158 million on TB- drug research. The Bill and Melinda Gates Foundation has pledged $900 million over the next decade.
Four drug companies - Bayer, Novartis, AstraZeneca International and GlaxoSmithKline - now have units working on infectious diseases, including TB.
Bacteria, however, reproduce every 10 minutes or so, while it takes humans about 20 years to develop means to battle new strains, Iseman said.
"They have the ability to adapt to our drugs," he said. "So if you're in Vegas, you bet on the bugs."
Staff writer Karen Augé can be reached at 303-954-1733 or kauge@denverpost.com.
--------------------------------------------------------------------------------
A history of antibiotics and drug resistance
1920s-'50s: Scientists harness the power of living organisms to fight bacteria, ushering in the era of antibiotics.
1928: Scottish bacteriologist Alexander Fleming, above, accidentally discovers that a mold juice he names penicillin can kill staphylococcus bacteria.
1940: Oxford University pathologist Howard Florey isolates pure penicillin and demonstrates how it can cure a wide range of pathogens, including strep infections, gonorrhea and syphilis.
1943: Penicillin becomes the first antibiotic to be put in widespread use.
1944: Russian-born microbiologist Selman Waksman, working in the United States with soil microbiologist Albert Schatz, discovers streptomycin, a powerful antibiotic that proves effective against tuberculosis.
1958: American molecular geneticist Joshua Lederberg wins the Nobel Prize in medicine for demonstrating the way bacteria interact and exchange genetic material - a key concept behind drug resistance.
1967: The first penicillin-resistant pneumonococcal bacteria are reported in Papua New Guinea.
1968: Drug-resistant Shigella diarrhea kills 12,500 people in Guatemala.
1970-72: Penicillin-resistant gonorrhea spreads around the world, transmitted in part by U.S. servicemen, who contract the disease from prostitutes in Southeast Asia.
1976: Several weeks after attending an American Legion convention in Philadelphia, 34 people die from a mysterious form of pneumonia that thwarts available treatments and comes to be known as Legionnaires' disease.
1980s-'90s: The public-health effects of drug-resistant bacteria become clear, prompting new concerns about infectious diseases.
1986: The U.S. Food and Drug Administration, the Centers for Disease Control and Prevention, and the Department of Agriculture establish a national anti-
microbial-resistance monitoring system to track food-borne microbes.
1988-95: Studies in Finland, the Netherlands and other European countries find increased drug resistance in farm animals. Many of the livestock are fed antibiotics as growth-promoters.
1990: Puppeteer Jim Henson, creator of the Muppets, dies of toxic-shock syndrome induced by an aggressive strain of streptococcus that acts too quickly for antibiotics to work.
1992: An influx of immigrants sparks a tuberculosis epidemic in New York and other cities, forcing local officials to remobilize dormant TB prevention efforts. The federal government is spending just $55,000 a year monitoring drug resistance.
1995: A form of staph infection that is resistant to methicillin results in almost a half-billion dollars in direct medical costs and claims 1,409 lives in New York City hospitals.
1996: Japanese bacterial geneticists detect the world's first staph infection capable of resisting the powerful antibiotic vancomycin.
1997: Health officials report the percentage of antibiotic-resistant cases has surged from 2 percent in 1991 to 43 percent in 1997.
1998: The Institute of Medicine contends that overuse of antibiotics has brought about widespread drug resistance, estimating that as many as half of the prescriptions for the drugs given each year to outpatients are unnecessary. The U.S. Centers for Disease Control and Prevention spends more than $11 million a year monitoring drug resistance.
2000: The Food and Drug Administration approves one of the newest major new antibiotics, Bayer's ciprofloxacin hydrochloride, known as Cipro. Cipro makes news the following year as a treatment for a spate of unsolved anthrax poisonings.
Denver Post Staff Writer
The Denver Post
The last time a new tuberculosis drug was developed, Richard Nixon was in the White House and Dr. Michael Iseman was a young resident in a New York City hospital.
That drug, Rifampin, "was the biggest thing to hit TB in 30 years," said Iseman, now a doctor at National Jewish Medical and Research Center in Denver.
Since then, Iseman has become a recognized authority on TB and Rifampin has remained the centerpiece of TB treatment.
Now, however, a growing number of tuberculosis strains are not fazed by the drug - as in the highly publicized case of Andrew Speaker, who is being treated at National Jewish.
Tuberculosis isn't the only infection increasingly impervious to the antibiotics in medicine's arsenal.
In the past decade, federal agencies - such as the Centers for Disease Control and Prevention, the National Institutes of Health, and the Food and Drug Administration - have warned that antibiotic overuse has led to evolving drug-resistant bacteria.
At the same time, the agencies say, there is a dearth of research dollars for new antibiotics - creating a looming medical crisis.
"Infections that were once easily curable with antibiotics are becoming difficult, even impossible, to treat," the Infectious Disease Society of America warned in its report "Bad Bugs, No Drugs."
"The problem is dollars, not chemistry," said Christopher Spivey, a spokesman for the Boston-based Alliance for the Prudent Use of Antibiotics.
Antibiotics not as profitable
Antibiotic development requires huge investments of money, $400 million to $800 million, according to a study in the journal Clinical Infectious Diseases.
To provide as much income as drug companies get from the sale of one drug to a person who, for example, takes a weight-loss pill daily, a company would have to sell antibiotics to 200 to 500 people with an illness like pneumonia, Spivey said.
There are currently under development 50 drugs each for obesity, pain and Type II diabetes, according to PhRMA, a group representing the nation's leading drugmakers.
There are just nine new drugs in the works for tuberculosis and eight for malaria.
For staph infections and drug- resistant staph infections, PhRMA lists 23 drugs under development.
This isn't a new trend. FDA approval of new anti-bacterial drugs has dropped 56 percent in 20 years, according to a 2004 study by Brad Spellberg, a professor of medicine at the University of California, Los Angeles.
Work on new TB drugs has languished in part because of the widespread, mistaken belief that the disease was no longer a problem in this country, said Mel Spigelman, director of research and development for the Global Alliance for TB Drug Development.
Iseman said that on the world market drugmakers are discouraged from developing antibiotics.
"There is a tendency - in global use - for knock-offs," Iseman said. "Companies simply choose not to honor patent protections and it's done under the seemingly noble rubric of, 'we have patients dying of - whatever disease - in our country and we can't afford your drug, so we're going to make our own.' "
In its report, the infectious-disease society recommended incentives, such as tax breaks, for antibiotic research and development.
Difficult to draw attention
Still, drug companies don't get much public sympathy these days, which could make it politically tough for members of Congress to grant those tax breaks, Iseman said.
Antibiotic development "won't get on the radar until there is a really good killing plague," Spivey said.
In that respect, Speaker may have unintentionally done a favor for TB drug research by drawing attention to the disease, Spivey said.
Since 2000, interest in TB has picked up, said the TB Alliance's Spigelman.
While only a handful of new TB drugs are in the pipeline, even that is progress, Spigelman said.
"In 2000, we had zero," he said.
This year, the National Institutes of Health will spend $158 million on TB- drug research. The Bill and Melinda Gates Foundation has pledged $900 million over the next decade.
Four drug companies - Bayer, Novartis, AstraZeneca International and GlaxoSmithKline - now have units working on infectious diseases, including TB.
Bacteria, however, reproduce every 10 minutes or so, while it takes humans about 20 years to develop means to battle new strains, Iseman said.
"They have the ability to adapt to our drugs," he said. "So if you're in Vegas, you bet on the bugs."
Staff writer Karen Augé can be reached at 303-954-1733 or kauge@denverpost.com.
--------------------------------------------------------------------------------
A history of antibiotics and drug resistance
1920s-'50s: Scientists harness the power of living organisms to fight bacteria, ushering in the era of antibiotics.
1928: Scottish bacteriologist Alexander Fleming, above, accidentally discovers that a mold juice he names penicillin can kill staphylococcus bacteria.
1940: Oxford University pathologist Howard Florey isolates pure penicillin and demonstrates how it can cure a wide range of pathogens, including strep infections, gonorrhea and syphilis.
1943: Penicillin becomes the first antibiotic to be put in widespread use.
1944: Russian-born microbiologist Selman Waksman, working in the United States with soil microbiologist Albert Schatz, discovers streptomycin, a powerful antibiotic that proves effective against tuberculosis.
1958: American molecular geneticist Joshua Lederberg wins the Nobel Prize in medicine for demonstrating the way bacteria interact and exchange genetic material - a key concept behind drug resistance.
1967: The first penicillin-resistant pneumonococcal bacteria are reported in Papua New Guinea.
1968: Drug-resistant Shigella diarrhea kills 12,500 people in Guatemala.
1970-72: Penicillin-resistant gonorrhea spreads around the world, transmitted in part by U.S. servicemen, who contract the disease from prostitutes in Southeast Asia.
1976: Several weeks after attending an American Legion convention in Philadelphia, 34 people die from a mysterious form of pneumonia that thwarts available treatments and comes to be known as Legionnaires' disease.
1980s-'90s: The public-health effects of drug-resistant bacteria become clear, prompting new concerns about infectious diseases.
1986: The U.S. Food and Drug Administration, the Centers for Disease Control and Prevention, and the Department of Agriculture establish a national anti-
microbial-resistance monitoring system to track food-borne microbes.
1988-95: Studies in Finland, the Netherlands and other European countries find increased drug resistance in farm animals. Many of the livestock are fed antibiotics as growth-promoters.
1990: Puppeteer Jim Henson, creator of the Muppets, dies of toxic-shock syndrome induced by an aggressive strain of streptococcus that acts too quickly for antibiotics to work.
1992: An influx of immigrants sparks a tuberculosis epidemic in New York and other cities, forcing local officials to remobilize dormant TB prevention efforts. The federal government is spending just $55,000 a year monitoring drug resistance.
1995: A form of staph infection that is resistant to methicillin results in almost a half-billion dollars in direct medical costs and claims 1,409 lives in New York City hospitals.
1996: Japanese bacterial geneticists detect the world's first staph infection capable of resisting the powerful antibiotic vancomycin.
1997: Health officials report the percentage of antibiotic-resistant cases has surged from 2 percent in 1991 to 43 percent in 1997.
1998: The Institute of Medicine contends that overuse of antibiotics has brought about widespread drug resistance, estimating that as many as half of the prescriptions for the drugs given each year to outpatients are unnecessary. The U.S. Centers for Disease Control and Prevention spends more than $11 million a year monitoring drug resistance.
2000: The Food and Drug Administration approves one of the newest major new antibiotics, Bayer's ciprofloxacin hydrochloride, known as Cipro. Cipro makes news the following year as a treatment for a spate of unsolved anthrax poisonings.
Thursday, June 14, 2007
Too many antibiotics? Use could lead to resistant bacteria
By Matt Whetstone, Cadillac News
Philosophies about antibiotics are changing.
While antibiotics are great to treat disease, there is a drawback. In a nation where people have become increasingly reliant on antibiotics, bacteria have become increasingly resistant to the drugs.
In the medical community, beginning to change the way things are done truly begins by changing attitudes.
Oftentimes, patients enter a doctor’s office insistent on receiving antibiotics.
In a study performed using patients with strep throat, two groups were given antibiotics while a third was given a placebo. In the two groups given antibiotics, resistance levels rose by 50 percent.
The group given the placebo saw no increase in antibiotic resistance.
In Dr. Gerald Herring’s antibiotic toolbox, he has six options.
That’s six different chances to treat a bacterial infection in children.
“In general, the more antibiotics we use, the higher incidence of bacteria becoming resistant to antibiotics,” said Herring, a physician at Mackinaw Trail Pediatrics in Cadillac.
Another concern is that overusing antibiotics at a young age can cause children to become sensitized to a drug and result in allergic reactions, Herring said.
All of a sudden, six options could be cut in half.
The Centers for Disease Control calls antibiotic resistance one of the world’s most pressing public health problems. Overuse can mean longer-lasting illnesses, more doctor visits or extended hospital stays. Illnesses once easily treated could become much more difficult to remedy.
“A lot of patients still think they need antibiotics for colds,” Herring said. “There are a lot of misconceptions out there in the public.”
Take for example ear infections. It’s something Herring sees all the time as a pediatrician. When treating a child, Herring said he asks himself if the body can deal with an infection or if it needs some help.
Yet, 80 percent of ear infections heal on their own and in about the same time as if an antibiotic were used, Herring said.
It becomes more pressing to use antibiotics for an ear infection if a child has a high fever or if things are not improving after a few days. Not using antibiotics mean careful observation and treating the child’s symptoms.
For adults, doctors have more options when it comes to antibiotics but Herring said it’s the same situation.
“It’s a question of rethinking for physicians and re-educating of patients to teach them they don’t always need antibiotics,” he said.
Dr. James Wilson, Medical Director for District Health Department No. 10, said doctors weigh the risks versus the benefits when determining if an antibiotic is necessary. It means thinking short, intermediate and long term.
“Generally, it’s not good to be on antibiotics for a long time,” he said.
Like anything else, Wilson said microbes are constantly evolving and they will mutate if it can make them more resistant to antibiotics.
While there are many beneficial alternative treatment options, Wilson said there’s not always an incentive to use them under the U.S. medical system.
Likewise, alternative therapies are not regulated by the Food and Drug Administration, meaning it’s difficult to get information on the risks and benefits, he said.
Your local connection
What are bacteria and viruses?
Bacteria are single-celled organisms found everywhere. Many are not harmful but some can trigger illnesses, such as strep throat and some ear infections.
Viruses are smaller than bacteria and cause illnesses by invading healthy cells and reproducing.
What kinds of infections are caused by viruses and should not be treated with antibiotics?
Colds, flu, most coughs and bronchitis, sore throats (except those resulting from strep throat).
How do I know if an illness is caused by a viral or bacterial infection?
It is difficult, consult with a physician.
What is antibiotic resistance?
Antibiotic resistance occurs when bacteria change in a way that reduces or eliminates the effectiveness of antibiotics. These resistant bacteria survive and multiply, causing more harm, such as longer illness, more doctor visits and a need for more expensive and toxic antibiotics.
When do I need to take antibiotics?
Antibiotics should only be used when prescribed by a doctor to treat bacterial infections.
What can I do to avoid antibiotic resistant infections?
Talk to your doctor about antibiotic resistance. Ask if an antibiotic is likely to be effective in treating your illness.
Do not demand an antibiotic when a doctor determines one is not appropriate. Ask what else you can to do help relieve your symptoms.
How can a child be protected from antibiotic-resistant bacteria?
Use only if a doctor determines it will be effective. Antibiotics will not cure most colds, coughs, sore throats or runny noses. Children fight off colds on their own.
Source: Centers for Disease Control
Philosophies about antibiotics are changing.
While antibiotics are great to treat disease, there is a drawback. In a nation where people have become increasingly reliant on antibiotics, bacteria have become increasingly resistant to the drugs.
In the medical community, beginning to change the way things are done truly begins by changing attitudes.
Oftentimes, patients enter a doctor’s office insistent on receiving antibiotics.
In a study performed using patients with strep throat, two groups were given antibiotics while a third was given a placebo. In the two groups given antibiotics, resistance levels rose by 50 percent.
The group given the placebo saw no increase in antibiotic resistance.
In Dr. Gerald Herring’s antibiotic toolbox, he has six options.
That’s six different chances to treat a bacterial infection in children.
“In general, the more antibiotics we use, the higher incidence of bacteria becoming resistant to antibiotics,” said Herring, a physician at Mackinaw Trail Pediatrics in Cadillac.
Another concern is that overusing antibiotics at a young age can cause children to become sensitized to a drug and result in allergic reactions, Herring said.
All of a sudden, six options could be cut in half.
The Centers for Disease Control calls antibiotic resistance one of the world’s most pressing public health problems. Overuse can mean longer-lasting illnesses, more doctor visits or extended hospital stays. Illnesses once easily treated could become much more difficult to remedy.
“A lot of patients still think they need antibiotics for colds,” Herring said. “There are a lot of misconceptions out there in the public.”
Take for example ear infections. It’s something Herring sees all the time as a pediatrician. When treating a child, Herring said he asks himself if the body can deal with an infection or if it needs some help.
Yet, 80 percent of ear infections heal on their own and in about the same time as if an antibiotic were used, Herring said.
It becomes more pressing to use antibiotics for an ear infection if a child has a high fever or if things are not improving after a few days. Not using antibiotics mean careful observation and treating the child’s symptoms.
For adults, doctors have more options when it comes to antibiotics but Herring said it’s the same situation.
“It’s a question of rethinking for physicians and re-educating of patients to teach them they don’t always need antibiotics,” he said.
Dr. James Wilson, Medical Director for District Health Department No. 10, said doctors weigh the risks versus the benefits when determining if an antibiotic is necessary. It means thinking short, intermediate and long term.
“Generally, it’s not good to be on antibiotics for a long time,” he said.
Like anything else, Wilson said microbes are constantly evolving and they will mutate if it can make them more resistant to antibiotics.
While there are many beneficial alternative treatment options, Wilson said there’s not always an incentive to use them under the U.S. medical system.
Likewise, alternative therapies are not regulated by the Food and Drug Administration, meaning it’s difficult to get information on the risks and benefits, he said.
Your local connection
What are bacteria and viruses?
Bacteria are single-celled organisms found everywhere. Many are not harmful but some can trigger illnesses, such as strep throat and some ear infections.
Viruses are smaller than bacteria and cause illnesses by invading healthy cells and reproducing.
What kinds of infections are caused by viruses and should not be treated with antibiotics?
Colds, flu, most coughs and bronchitis, sore throats (except those resulting from strep throat).
How do I know if an illness is caused by a viral or bacterial infection?
It is difficult, consult with a physician.
What is antibiotic resistance?
Antibiotic resistance occurs when bacteria change in a way that reduces or eliminates the effectiveness of antibiotics. These resistant bacteria survive and multiply, causing more harm, such as longer illness, more doctor visits and a need for more expensive and toxic antibiotics.
When do I need to take antibiotics?
Antibiotics should only be used when prescribed by a doctor to treat bacterial infections.
What can I do to avoid antibiotic resistant infections?
Talk to your doctor about antibiotic resistance. Ask if an antibiotic is likely to be effective in treating your illness.
Do not demand an antibiotic when a doctor determines one is not appropriate. Ask what else you can to do help relieve your symptoms.
How can a child be protected from antibiotic-resistant bacteria?
Use only if a doctor determines it will be effective. Antibiotics will not cure most colds, coughs, sore throats or runny noses. Children fight off colds on their own.
Source: Centers for Disease Control
Wednesday, May 30, 2007
Resistant Gens in Food
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.
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.
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.
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
Wednesday, April 18, 2007
Overuse Of Antibiotics-Creating Monsters Out Of Common Microbes
Health officials are alarmed at the evolution of causal organisms of hitherto common diseases into ‘superbugs’. This, they warn is the result of overzealous use of antibiotics.
One such example is the recent announcement by the U.S Centers For Disease Control (CDC) that gonorrhea has now become resistant to the antibiotic fluoroquinolones. The only line of treatment left is cephalosporins; a fact, which is creating worry lines on many a health expert.
Says Dr. Kevin Fenton, Director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention:“There is an urgent need for new, effective medicines to treat gonorrhea. We are running out of options to treat this serious disease. Increased vigilance in monitoring for resistance to all available drugs is essential.”
So, where lies the problem? Antibiotics are one of the most profound achievements in medicine, but decades of widespread and indiscriminate use in cosmetics and soaps and food animal production, has rendered many ineffective.
The practice goes on. One such example is that last month, the Food and Drug Administration, despite warnings from its own experts and health groups, gave the green light to treating cattle with an antibiotic; the fourth generation version of the one the CDC now urges for gonorrhea. Though the company that makes this antibiotic argued that similar drugs have been used in animals in Europe without harm, recent data indicates that bacteria resistance has grown not only in livestock but in humans as well.
Both the Government and private health organizations seem to agree that careful, limited use of antibiotics is crucial to public health, as microbes become more and more resistant to them. Still, the spread of gonorrhea is one indication of a thought yet to be put, into action.
Source-Medindia
ANN/V
One such example is the recent announcement by the U.S Centers For Disease Control (CDC) that gonorrhea has now become resistant to the antibiotic fluoroquinolones. The only line of treatment left is cephalosporins; a fact, which is creating worry lines on many a health expert.
Says Dr. Kevin Fenton, Director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention:“There is an urgent need for new, effective medicines to treat gonorrhea. We are running out of options to treat this serious disease. Increased vigilance in monitoring for resistance to all available drugs is essential.”
So, where lies the problem? Antibiotics are one of the most profound achievements in medicine, but decades of widespread and indiscriminate use in cosmetics and soaps and food animal production, has rendered many ineffective.
The practice goes on. One such example is that last month, the Food and Drug Administration, despite warnings from its own experts and health groups, gave the green light to treating cattle with an antibiotic; the fourth generation version of the one the CDC now urges for gonorrhea. Though the company that makes this antibiotic argued that similar drugs have been used in animals in Europe without harm, recent data indicates that bacteria resistance has grown not only in livestock but in humans as well.
Both the Government and private health organizations seem to agree that careful, limited use of antibiotics is crucial to public health, as microbes become more and more resistant to them. Still, the spread of gonorrhea is one indication of a thought yet to be put, into action.
Source-Medindia
ANN/V
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