Invasion of the Superbugs

Bacteria are waging a battle against antibiotics, which are overused and too often ineffective. But we can still win the war.

Antibiotics are the bedrock of modern medicine. In 1900 the bacterial infections pneumonia and tuberculosis were among the top three causes of death in the United States. It wasn’t until the early ’50s that science fully understood the potential of antibiotics and family doctors began dispensing them regularly, ushering in what’s referred to as medicine’s “golden age.”

“They really are miracle drugs,” says Karl Drlica, PhD, professor of microbiology and molecular genetics at the UMDNJ–New Jersey Medical School in Newark. “You can feel like you’re on your deathbed one day and a few days later you feel fine.”

In the early days, antibiotics were so precious that they were carefully rationed. Today, such scarcity is hard to imagine. Patients beg their doctors for the magic pills at the slightest hint of a sore throat. And industrial application has increased in the name of cleanliness and health. Fruit growers spray antibiotics on orchards; companies add antibacterial components to hand soaps; farmers mix antibiotics into livestock feed.

The problem is that the more ubiquitous antibiotics become in our health ecosystem, the less potent they are. Bacteria are smart, and over the years, thanks to constant exposure to certain drugs, a handful of the strongest bugs have figured out how to outmaneuver standard antibiotics. Simply put, says Drlica, coauthor of Antibiotic Resistance: Understanding and Responding to an Emerging Crisis (FT Press, 2011), the qualitative difference between antibiotics and other drugs is that the more antibiotics are used, the less effective they become.

“Overuse of these drugs anywhere is a threat to health everywhere,” says Gail Hansen, DVM, MPH, an epidemiologist and senior officer at the Pew Campaign on Human Health and Industrial Farm-ing, an organization advocating against the overuse of antibiotics.

Certain bacteria — often referred to as superbugs — are now evolving so rapidly that they are outpacing our ability to bring new antibiotics to market, making garden-variety ills, like urinary tract infections and strep throat, increasingly difficult to treat. Conditions that just a few years ago were little more than a nuisance can turn deadly. “A bug may kill you before doctors land on an antibiotic that will work,” says Charles Gerba, PhD, an environmental microbiologist at the University of Arizona and coauthor of The Germ Freak’s Guide to Outwitting Colds and Flu (Health Communications Inc., 2005).

A superbug is basically a bacterium that resists one or more antibiotics. And any bacterium can become a superbug. Faced with an antibiotic — made by a good-guy microbe that blocks or kills bad-guy microbes — nearly all of the targeted bad guys will die, but a few will survive. Those that survive are now resistant to the drug, and the antibiotic-resistant bacteria can pass their resistance to friends and offspring. “If you have one bacterium that is resistant to an antibiotic, within 24 hours you’ll have a billion bacteria that are resistant to that same antibiotic,” says Hansen. The cycle continues, and at some point a few elite bugs can become resistant to every class of antibiotics in the pharmacy.

Not all superbugs are resistant to all antibiotics, but enough are that people are starting to die from infections that were once curable. Brad Spellberg, MD, infectious disease specialist at Harbor-UCLA Medical Center and author of Rising Plague: The Global Threat From Deadly Bacteria and Our Dwindling Arsenal to Fight Them (Prometheus Books, 2009), likens antibiotic resistance in medicine to the Titanic’s maiden voyage. “The first sign that the ship has hit the iceberg is when you’ve got people dying of untreatable infections,” he says. “Unless we do something fast, we are all at risk of drowning.”

Reports of killer bacteria in hospitals, such as the dreaded MRSA (methicillin-resistant Staphylococcus aureus), are rampant. In 2002 (the most recent year for which data is available) 99,000 Americans died from infections they caught in the hospital, meaning they checked in for one thing — an appendectomy, a lumpectomy or a hip replacement — but died of a superbug acquired during their stay.

More Americans are killed by these hospital infections than by AIDS, breast cancer and car accidents combined. The medical community is racing to educate doctors on how to slow the spread with proper hygiene and judicious use of the prescription pad.

With everyone’s energy focused on reducing infection transmission in the healthcare system, though, an equally dangerous situation was developing on feedlots. And while most healthcare professionals grasp how alarming the situation has become, the same can’t be said of many livestock farmers.

In 2010 the Food and Drug Administration (FDA) began publishing details about the amount of antibiotics sold for humans versus animals. The numbers were shocking. In 2011, 80 percent of all antibiotics sold went to animals versus only 20 percent for people. As a result, the dangerous bacteria that can be transferred to humans in the food supply has both proliferated and gotten stronger. The revelation was a wake-up call.

“We are hastening the demise of antibiotics by allowing the drugs to be mishandled,” says David Wallinga, MD, senior adviser in science, food and health at the Institute for Agriculture and Trade Policy. “Our sloppiness is what allows superbugs to evolve.”

So little is changing in feedlots, in fact, that medical organizations are begging the federal government to take action. Recently, a chorus of medical and public health groups, including the American Medical Association, the World Health Organization and the American Academy of Pediatrics, called for an end to the overuse and misuse of antibiotics in livestock.

“Antibiotic resistance is going to create an epidemic that kills a lot of people,” says Wallinga, cofounder of Keep Antibiotics Working, an organization dedicated to ending overuse. “It’s not a question of ‘if,’ it’s a question of ‘when.’”

Drugs Down on the Farm

The arrival of antibiotics on the farm in the ’50s coincided with the emergence of industrial-size livestock farming. Big companies using large-scale practices, such as feedlots, became the norm, and consumers started enjoying lower meat prices at the grocery store. The impact of this mass production, according to Pew’s Hansen, who is also a veterinarian, is that “when you raise animals in very close quarters — beak to beak, nose to nose, hoof to hoof — even if conditions are perfectly clean, disease can spread like wildfire.

“[That spread] is exacerbated by things like weaning animals too early and feeding them food they aren’t meant to eat, like corn, which can disrupt their health,” she says.

At first, antibiotics were given only to sick animals. But livestock farmers soon found that a daily, low-dose antibiotic could help livestock live in spite of filthy surroundings and low-grade food. An unexpected perk was that the antibiotics caused weight gain. The exact mechanism is unknown, but some experts speculate the extra poundage is due to a bacterial imbalance in the animal’s gut that flips on its fat-storage genes. Having fat livestock is a boon for farmers because animals are sold by weight.

Because farmers can buy antibiotics over the counter, the practice of adding them to animal feed was logical and profitable. It was also scattershot.

The Union of Concerned Scientists estimates that 70 percent of all antibiotics used in the United States are given to healthy livestock.

Once bacteria show up on the feedlot, the human population is vulnerable, because superbugs love to travel — and one of their favorite vehicles is meat.

A common misperception is that bacteria are only inside the meat. Bacteria are also on the meat. During processing, the surface of meat is often dirtied by bacteria from the animals’ skin. Bacteria, usually dried feces, splatters onto the animals’ muscles and fat. You can’t see them, but these fecal droplets teem with bugs, like Salmonella, E. coli and Cryptosporidium. Because many animals are kept on low-dose antibiotics, these sorts of bugs have done daily battle with antibiotics. The ones that make it out alive are the fittest of the fit.

In retail spot checks, the FDA routinely finds superbugs on both red meat and poultry. “You won’t necessarily get sick,” says Wallinga, “but it is a route of transmission. You can pass it on to others who may be more susceptible.”

In the kitchen, superbugs easily spread to smooth surfaces such as knives, cutting boards and countertops. Unless fresh produce and meat are scrupulously washed off and cooked, bacteria can reach our stomachs and wreak havoc with our guts. (Fruits and vegetables can be sources of transmission because animal manure in runoff and groundwater can contaminate plants.)

Infections spawned by superbugs are more tenacious than those sparked by regular bacteria. “We’ve seen a large uptick in infections that can’t be treated with oral antibiotics, especially urinary tract infections,” says Spellberg. “These people have to be hospitalized and put on intravenous antibiotics because nothing else works.” Ninety percent of deaths from food-borne illness are caused by five major food-borne agents, including three strains of bacteria that have each spawned superbugs: Salmonella, Campylobacter and E. coli.

Reversal of Fortunes

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Life without antibiotics is difficult to imagine. Surgery would be out of the question because of infection risk. Conditions now considered mundane, like a strep throat or even a skinned knee, could be life threatening. “The loss of antibiotics is second only to climate change in terms of threats to human survival,” says Drlica.

The United States has a booming pharmaceutical industry, so, you might ask, why can’t corporate scientists and researchers get us out of this mess? The answer to that question may simply come down to incentive. It costs roughly $800 million for a pharmaceutical company to bring a new drug to market, and the average Joe needs antibiotics for only a week or so. In comparison, most folks with chronic diseases, such as heart disease and diabetes, take prescription drugs for years, allowing pharmaceutical companies to rake in the dough.

All is not lost, however. There is a slight trickle of new antibiotics under review at the FDA, including drugs to fight MRSA in hospitals. Wallinga also says there’s promise in the idea of taking certain antibiotics out of circulation for a period of time, which would help shed resistance. Then experts could reintroduce the same drugs with the caveat that physicians exercise more restraint when writing prescriptions.

In the meantime, one strategy to rein in antibiotic use is to pressure politicians to regulate drug use in livestock. Recently, both the U.S. House and Senate put forth measures to address the issue, but the FDA remains wishy-washy, which leaves everyone in flux. Livestock growers in the United States worry that stricter regulations will send meat prices soaring, but they would do well to consider Denmark — an international role model for how to practice large-scale farming with fewer antibiotics. Denmark is the world’s leading pork exporter, yet farmers have cut antibiotic use by 60 percent, using them only to treat sick animals. They did it through such measures as keeping pigs’ environments cleaner, improving ventilation systems and allowing piglets to stay with sows longer to naturally bolster their immune systems.

You can also flex your purchasing power by buying organic meat or meat that’s raised without antibiotics. (If you choose to buy conventionally raised meat, the likelihood of purchasing a contaminated product is sobering: In 2010, tests revealed that nearly 52 percent of chicken breasts were contaminated with antibiotic-resistant E. coli.) If enough consumers refuse to buy meat and poultry raised with antibiotics, retailers will get the message.

There are also many commonsense ways to reduce your odds of hosting a superbug, such as increasing your immunity through good nutrition, sleep, stress relief and regular exercise; washing your hands regularly; and cooking your meat to correct internal temperatures to kill most bad bugs. (For more information, see “How to Protect Yourself,” below.) In the meantime, the global health community is rallying around the issue and calling for significant changes in the ways antibiotics are handled.

“As a global society,” says Drlica, “if we get scared enough, we will eventually develop new antibiotics and new strategies.”

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Catherine Guthrie is a Boston-based investigative food journalist.

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