Nearly half of the meat and poultry samples, 47 percent, were contaminated with S. aureus, and more than half of those bacteria, 52 percent, were resistant to at least three classes of antibiotics, according to the study published Friday in the journal "Clinical Infectious Diseases," a publication of the Infectious Diseases Society of America.
The study by the Translational Genomics Research Institute used DNA testing to demonstrate that the food animals themselves were the major source of contamination.
Researchers collected and analyzed 136 samples covering 80 brands of beef, chicken, pork and turkey from 26 retail grocery stores in five U.S. cities: Los Angeles, Chicago, Fort Lauderdale, Flagstaff and Washington, DC.
Raw meat may be contaminated with drug-resistant staph. (Photo by Winfried Mosler)
"For the first time, we know how much of our meat and poultry is contaminated with antibiotic-resistant Staph, and it is substantial," said Lance Price, PhD, senior author of the study and director of TGen's Center for Food Microbiology and Environmental Health.
"The fact that drug-resistant S. aureus was so prevalent, and likely came from the food animals themselves, is troubling, and demands attention to how antibiotics are used in food-animal production today," Dr. Price said.
Densely-stocked industrial farms, where food animals are steadily fed low doses of antibiotics, are ideal breeding grounds for drug-resistant bacteria that move from animals to humans, finds the research, supported through a grant from The Pew Charitable Trusts as part of The Pew Campaign on Human Health and Industrial Farming.
Although staph should be killed with proper cooking, it may still pose a risk to consumers through improper food handling and cross-contamination in the kitchen. Click here for tips on how to avoid staph contamination in the kitchen.
S. aureus can cause a range of illnesses from minor skin infections to life-threatening diseases, such as pneumonia, endocarditis and sepsis.
Lance Price (Photo courtesy NAU)
"Antibiotics are the most important drugs that we have to treat staph infections; but when staph are resistant to three, four, five or even nine different antibiotics, like we saw in this study, that leaves physicians few options," said Dr. Price, a senior science advisor at the Pew Charitable Trusts..
"The emergence of antibiotic-resistant bacteria, including staph, remains a major challenge in clinical medicine," said Paul Keim, PhD, director of TGen's Pathogen Genomics Division and director of the Center for Microbial Genetics and Genomics at Northern Arizona University in Flagstaff.
Paul Keim (Photo courtesy TGen)
"This study shows that much of our meat and poultry is contaminated with multidrug-resistant staph. Now we need to determine what this means in terms of risk to the consumer," said Dr. Keim, a co-author of the paper.
The U.S. government routinely surveys retail meat and poultry for four types of drug-resistant bacteria, but S. aureus is not among them. The paper suggests that a more comprehensive inspection program is needed.
On April 7, World Health Day, the Infectious Diseases Society of America, IDSA, rolled out a plan to combat deadly antibiotic-resistant "super bugs."
"The way we've managed our antibiotics for the past 70 years has failed. Antibiotics are a precious resource, like energy, and we have a moral obligation to ensure they are available for future generations," said IDSA President James Hughes, MD.
"IDSA has a comprehensive, multifaceted plan to address this crisis, but time is running out. If such measures are not implemented now by Congress, federal agencies and health care providers across the country an increasing number of lives will be devastated and lost."
"Infections are becoming increasingly resistant to existing antibiotics, while the number of new antibiotics being developed has plummeted," said Dr. Hughes.
IDSA is ringing the alarm bells loudly, saying, "Unless sweeping actions are taken now, the future could resemble the days before these miracle drugs were developed."
Frequent use of antibiotics has led to drug-resistant strains of staph. (Photo by Julia Anderson)
"People will die of common infections and many medical interventions we take for granted - surgery, chemotherapy, organ transplantation, and premature infant care - will no longer be possible," the IDSA predicts.
The incidence of antibiotic-resistant bacteria, including methicillin-resistant Staphylococcus aureus, MRSA, Acinetobacter baumannii, Klebsiella, and others has skyrocketed over the past two decades. Each year, these infections kill nearly 100,000 U.S. hospital patients and are increasingly affecting healthy people as well.
But while 16 new antibiotics were approved between 1983 and 1987, only two have been approved since 2008.
The crisis is so dire, the World Health Organization has made antibiotic resistance the central focus of this year's World Health Day, a day held each year to highlight a global public health issue of critical concern.
In the United States, the IDSA supports legislative and administrative action to address the problem, and two bills, the Strategies to Address Antimicrobial Resistance (STAAR) Act and the Generating Antibiotic Incentives Now (GAIN) Act, are good first steps, but IDSA believes they can do more.
As a first step to turn the tide, IDSA recommends creating incentives, and removing economic and regulatory disincentives, for antibiotic research and development so companies find developing new antibiotics a viable business endeavor.
IDSA's goal is to have 10 new systemic antibiotics by 2020, known as the 10 x '20 initiative. Since the initiative was launched in April 2010, one new antibiotic has been approved.
"Infectious diseases specialists around the country can tell you stories about formerly healthy patients who died because physicians ran out of antibiotics that worked," said Brad Spellberg, MD, associate professor of medicine at the Geffen School of Medicine at the University of California at Los Angeles, Los Angeles Biomedical Research Institute.
"We're facing a day in the not-too-distant future where people will be outraged with our inability to treat infectious diseases, and wonder why something wasn't done earlier," said Dr. Spellberg. "The IDSA plan lays out innovative approaches that can and should be enacted, but they must be done now. The longer we wait, the bigger and more costly the problem will become both in terms of lives lost and health care expenditures."
Copyright Environment News Service (ENS) 2011. All rights reserved.