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By Arthur Allen

June 11, 1999 | Bacterial resistance threatens to disable our health-care system, but it still brings a glint of wonderment to J. Glenn Morris' eyes. "From a scientific standpoint, it is fascinating to watch," says Dr. Morris, chief epidemiologist at the University of Maryland Medical Center. "As a physician, it's scary as hell."

Across the United States, and the world, bacteria and other microorganisms are challenging medical arsenals. A half century of antibiotic overuse -- in doctors' offices and hospitals, but also in livestock feed and antibacterial hand creams -- has provoked the opposite of its intent. Instead of a world safe from infectious bugs, we have a world where the most stubborn bugs survive. Already, drug-resistant bacteria are killing thousands of people each year. It's not too simplistic to say that we're racing the bugs to save such endeavors as neonatology, organ transplants and cancer chemotherapy, none of which could exist without effective antibiotics. "You don't know how the race is going to go," says Christopher Walsh, a Harvard Medical School professor of pharmacology and biochemistry. "You could be a strategic optimist and say the basic science is bound to save us in the nick of time. Or you could be a defensive pessimist and say we're going to be in a post-antibiotic era for a while."

At the 750-bed downtown Baltimore hospital monitored by Morris, a bearded man with gentle blue eyes, the post-antibiotic era has, in a limited sense, already arrived. In 1992 the medical center had the dubious honor of becoming one of the first hospitals in America to detect colonies of vancomycin-resistant bacteria called enterococci. Vancomycin -- a drug known in intensive care units as "the Big Gun," or "The Mighty Vanc"-- is a powerful antibiotic. Doctors began flooding surgical patients with vancomycin in the 1980s when Staphylococcus aureus, the cause of "staph" infections, developed widespread resistance to an earlier miracle drug, methicillin. Today, methicillin-resistant staphylococcus and vancomycin-resistant enterococcus are endemic to Morris' hospital. Carriers are isolated in separate rooms where staff and visitors are ordered to wear gloves and gowns. But despite efforts to control their spread from patient to patient, the bugs "are here to stay," says Morris.

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Random samples show vancomycin-resistant enterococci in up to 25 percent of all patients at the hospital, Morris says. What this means is that vancomycin resistance isn't just in the hospital -- it's walking the red-brick streets of the city spread below Morris' ninth-floor window. And it kills, although Morris can't say how often. (At most hospitals, infection control officers won't even talk to reporters.) "No hospital will admit that people are dying of resistant bacteria they acquired in that hospital," says Morris. But they are dying. In 1997, 90,000 people died in U.S. hospitals while infected with hospital-acquired bacteria -- 70 percent of which were antibiotic-resistant strains, according to Dr. Stuart Levy of Tufts University in Massachusetts (although infection was not necessarily the major cause of all or even a majority of those deaths).

Luckily for most of us, enterococci are dangerous only to patients with compromised immune systems. But enterococci will seem like mother's milk if and when vancomycin resistance becomes a factor in staph infections. Staphylococcus aureus "can cause havoc and death to even otherwise healthy people," says Levy.

Staphylococcus, a bacteria that colonizes the noses of one in five people, has proven over the years to be among the most adaptable bacteria. Targeted with penicillin in 1942, by 1948 staph was largely resistant. Erythromycin was introduced in 1952 and quickly lost its bite, leading to raging hospital infections. Methicillin, introduced in 1960, was effective for longer -- until the mid-1980s. Now vancomycin is the magic bullet.

It's not that bugs are "outsmarting" us; they're as dumb as they seem. As a class, though, they are certainly less individualistic than we are. Bacteria are indifferent to how they get their genes. They'll mutate, have sex with cousins and strange species or gobble up free-floating DNA. Sworn to the Hippocratic oath, doctors will throw everything in their arsenal at bacteria to save one patient. "A million bacteria get their heads blown off for every one that survives" an antibiotic, says Dr. Abigail Salyers of the University of Illinois. But a few do survive -- and each resistant survivor and its progenitors gain Lebensraum in the body each time the antibiotic is used again, killing off the bacteria that lack genes to adapt.

Next page | Like supercomputers, bacteria crack antibiotic codes