“Drug-resistant bacteria represent one of the greatest threats to our species,” says ethnobotanist Mark Plotkin, president of the Amazon Conservation Team, which works with people in the Amazon region to conserve forests and culture. Coauthor Michael Shnayerson, a contributing editor at Vanity Fair, agrees. “People have no idea what bacterial dangers await them when they go to a hospital,” he says. In a new book Killers Within: The Deadly Rise of Drug-Resistant Bacteria, Shnayerson and Plotkin report medical researchers’ evidence that the number of disease-causing bacteria able to fend off the most commonly prescribed antibiotics has grown significantly. We live in a “grim new era” of superbugs, say the authors, who cite scientific studies suggesting that we have only ourselves to blame. Physicians who prescribe antibiotics when the medications are not necessary, patients who don’t complete antibiotic treatments, and ranchers who overuse antibiotics to spur livestock growth have all contributed to the development of extra-hardy bacteria strains—a microbial world acting out the old saying that what doesn’t kill you makes you stronger. The toll is huge. Public health experts estimate that infections from antibiotic-resistant bacteria kill some 40,000 Americans annually. Killers Within highlights efforts by experts to curb the problem and to develop new antimicrobial medications. In the excerpt that follows, scientists research powerful natural substances that some animals secrete to fight off infection—substances that may lead to the antibiotics of the future.
The first time he stalked a dragon, in November 1995, Terry Fredeking was scared. Bad enough to have flown all the way to Indonesia, deal with notoriously difficult Indonesian bureaucrats, brave the stifling heat, and find a local boat owner willing to whisk the biologist and two colleagues over to the sparsely inhabited island of Komodo. Worse, much worse, to lie in wait, awash with sweat, for the world’s largest lizard to emerge from the forest in a hungry mood. That first time, Fredeking watched a Komodo dragon attack a goat. The Komodo was at least eight feet long and weighed well over 200 pounds. It looked like a dinosaur, Fredeking thought, it really did. It was almost all scales, with a huge mouth of large, curved teeth. One second it was lying in wait, all but invisible. The next, it was ripping out the terrified goat’s stomach with a single bite. As it did, thick saliva dripped from the dragon’s mouth, mixing with the blood and guts of the goat. Ah, yes, the saliva, thought Fredeking as he and his colleagues advanced from the bushes, tremulously holding long forked sticks. The saliva was why they were here.
With luck, the dragon’s viscous, revolting drool would contain a natural antibiotic that in some synthesized form could fight multidrug-resistant Staphylococcus aureus, which causes sometimes fatal blood poisoning, and other bacterial pathogens. At the least, Fredeking, a genial, stocky, self-styled Indiana Jones from Hurst, Texas, would have the adventure of his life and possibly contribute to the fascinating new field of animal peptides. It sure beat collecting bat spit in Mexico and harvesting giant Amazonian leeches in French Guiana.
This latest approach to antibiotic discovery traced in large part to a well-ordered lab at the National Institutes of Health. On a fragrant, early summer day in June 1986, a mild-mannered M.D. and research scientist named Michael Zasloff had noticed something decidedly odd about his African clawed frogs. As chief of human genetics at a branch of the NIH, Zasloff was studying the frogs’ eggs to see what they could teach him about the flow of genetic information from the nucleus of a cell to the cytoplasm. He would inject genes into the eggs, then see what happened. The frogs just happened to have large, good eggs for this purpose; their own biology was irrelevant to his work.
Some lab scientists killed the frogs after cutting them open to remove their eggs. Not Zasloff. He would stitch them up crudely—he was a pediatrician, not a surgeon—and when enough of them accumulated in a murky tank in his lab, he would secretly take them to a nearby stream and let them go. On this particular day, Zasloff noticed that the tank appeared to have “something bad” in it, because several frogs had died overnight and were putrefying. But some of the frogs he’d operated on, sutured and thrown back into the tank appeared fine. Why was that? Certainly the frogs’ stitches were not tight enough to prevent bacteria and other microbes from infiltrating their bloodstreams. Yet no infection occurred. No inflammation, either.