../1198/space%20holder

Resistance Fighter , continued

 
    Several factors are involved in these new forms of resistance, but the most important “is that antibiotic use is out of control,” Levy says. Since 1954, the amount of antibiotics produced in the United States annually has increased from two million pounds to 50 million pounds. Research suggests that about half of these antibiotics aren’t medically necessary.
    “Everywhere you look these days, doctors are prescribing antibiotics for colds and earaches. But if all you’ve got is a common cold, you definitely don’t need an antibiotic,” Levy says. “Remember, colds are caused by viruses, not bacteria, and viruses are completely unaffected by antibiotics. If you use one, all you’ll get are side effects, resistant bacteria, and no help on the virus! Instead of resorting to the antibiotic, you need to eat well and drink lots of liquids. Get plenty of sleep, and take Tylenol or other anti-inflammatories that you can buy over the counter.”
    He also urges parents not to demand an antibiotic from their pediatrician at the first signs of a child’s earache. “Most earaches in kids don’t require an antibiotic, at least not at first,” he says. “And in many parts of Europe right now, 95 percent of kids are not given an antibiotic when they present with an ear infection. Instead, they wait 24 to 48 hours, and then there are only 10 or 15 percent who actually require it, because most earaches will just get better on their own. In the U.S., our best assessment is that two-thirds of earaches are caused by bacteria, but of those two-thirds, more than half will cure themselves. So I’d say that no more than one in five really needs an antibiotic.”
    Another frustrating recent development is the proliferation of “antibacterial” cleaning agents in household products. “I think many people are paranoid about germs, and that’s what has led to this mania for antibacterial-containing household products,” Levy says. “Antibacterial agents are in everything these days—plastics, deodorants, detergents. But like [medicinal] antibiotics, we want to reserve these products for the care of sick patients. They are not needed for everyday use. They, too, create environments of surviving resistant strains—and their use runs the risk of creating homes that are like hospitals [containing many resistant bacteria].
    While cleanliness and personal hygiene are important to preventing infection, “soap and water are a fine combination to do the job, along with ammonia, chlorinated compounds or alcohol. These products do not leave residues for the selection of resistant bacteria,” he says. “The important thing to remember is that bacteria are our allies. We need them to regenerate life, and to protect us from the rare, disease-causing kinds. Their resilience is what we rely on. They help our immune system mature, and to over-treat them will only get us into trouble.”
    Needlessly “killing off” bacteria with superfluous antibiotics gives a “selective advantage” to those which survive the assault, Levy explains. “When an antibiotic such as penicillin attacks a group of bacteria cells, those that are highly susceptible to the medicine will quickly die. Those cells that have had some resistance from the start, or that have acquired it through mutation or gene exchange with other bacteria, may manage to survive. Those same cells now face reduced competition from susceptible bacteria, and they will go on to proliferate. And so they become increasingly resistant to our drugs.”
    The consequences can be dire. In numerous published studies, Levy has demonstrated a link between human overuse of anti-bacterial drugs and increasing resistance among such formidable pathogens as tuberculosis, which, after being nearly eradicated, is now making an alarming comeback in the industrialized world. He also points to reports from the United States, Japan and Europe in recent years of vancomycin-resistant strains of Staphylococcus aureus, an often-deadly bacteria found in some hospitals. “Vancomycin is a powerful antibiotic, and it’s the last line of defense against a few strains of S. aureus,” he says. “The problem is that those strains now appear to have become resistant to all other antibiotics. So far, there have been four confirmed deaths in the world from drug-resistant forms of S. aureus, and that’s quite troubling. These organisms can cause failure of treatment, and if we don’t keep finding new drugs to stop them, they could emerge as a disaster for patients.”

The son of a family-practice M.D. in Wilmington, Delaware, Levy never doubted that he would eventually become a physician, but he majored in English at Williams College—the result of some “very good advice” from his father, he says. “My dad really understood the value of liberal arts for a doctor, and he helped convince me to major in English as an undergrad.”
    After graduating with honors, Levy went directly to medical school at Penn—though some highlights of his education occurred far from campus. He spent the summer after his second year studying in Italy, for example. “I found Penn to be really open-minded and tolerant toward its students,” Levy recalls with a laugh. “When I told them I wanted to spend a summer studying at the Istituto di Microbiologia in Milan, the people at the med school didn’t go up in arms, shouting: ‘You can’t do that!’
    “They gave me a nice stipend, and I went off—this was 1962—to work under the late Dr. Giulio Maccacaro, who was a great teacher and a great researcher. What a summer. An assistant professor would pick me up at my dormitory each morning, and I’d climb onto the back of his Vespa, and together we’d go roaring into Milan, to the laboratory.
    “We worked hard. But at the end of the day, Professor Maccacaro would often take us to one of the bars in the neighborhood, and he’d buy us a little bit of vermouth. Cinzano, red, with a twist of lemon. The Italians would quickly chug it up, like the Russians with their vodka. And I’d be sitting back, drinking it slowly, and they’d all say: ‘Hey, Stuart, andiamo! Andiamo!’”
    Levy was enchanted by his summer in cosmopolitan Milan: “We went to La Scala, and sat high up near the top in the cheap seats. [We heard operas by] Mozart and Rossini. I’ve loved both of them ever since.”
    After returning to Philadelphia, he barely had time to unpack his bags and take his “two-year medical boards,” before he again set sail for Europe—this time to spend a full academic year studying bacterial drug-resistance under renowned researcher Raymond Latarjet at the Laboratoire Pasteur in Paris.
    “I’m still amazed by the way the med school helped me arrange those two fellowships,” he says. “That was a terrific year, on many different levels. I’ve always felt grateful for the opportunities I received at Penn.”
    Levy completed his internship and residency training at New York’s Mount Sinai Hospital, and by the late 1960s was studying “bacterial genetics”—a growing interest during medical school—on a three-year fellowship at the National Institutes of Health in Bethesda, Maryland. He joined the faculty at Tufts University medical school in 1971, becoming a full professor in 1980. Meanwhile, his research into drug resistance among bacterial species was gaining international attention.
    The author or editor of five books and more than 200 scientific papers and journal articles on antibiotic use and resistance, he is credited with achieving several breakthroughs in his field. These include the discovery of the “efflux pump” resistance mechanism in bacteria, along with major new insights into the ways in which antibiotic-resistant bacteria are transferred from animals to humans and the location of the “protein master switch” that controls bacterial resistance.

previous page | next page

 

 


Sept/Oct Contents | Gazette Home

Copyright 2000 The Pennsylvania Gazette Last modified 8/23/00