New Hunt for Drug-Resistant Microbes

Alarmed by the growing threat of pathogens able to survive drugs meant to kill them, a grassroots network of scientists has sprung up to track a mostly ignored well of genes for these superpathogens: harmless bacteria in which resistance may first evolve. A working group of scientists from universities, drug companies, and government agencies is now laying plans for a public database to keep tabs on when and where specific antibiotic-resistance genes appear in order to help predict the spread of resistance.

Scientists and policy-makers agree that antibiotic resistance is a serious problem but have failed to reach a consensus on the best way to tackle it. Drug companies and health watchdogs such as the U.S. Centers for Disease Control and Prevention (CDC) have been monitoring antibiotic resistance in pathogens. These efforts "focus exclusively on human clinical pathogens," says Abigail Salyers, a microbiologist at the University of Illinois, Urbana-Champaign, who helped organize a meeting in Boston last week to plot strategy for the $100,000 effort. "I think that's too narrow."

The new group will focus on bacteria others have ignored--the harmless bugs that live in humans, animals, and even in soil and water. Widespread antibiotic use in both humans and animals spurs drug resistance in these harmless bacteria, and resistance genes can jump species lines into disease-causing bacteria, says meeting co-organizer Stuart Levy of Tufts University School of Medicine. For example, researchers say, the gene for tetracycline resistance apparently hopped from a normal gut-dwelling bacteria to Neisseria gonorrhoeae, which causes gonorrhea. Researchers suspect that a similar scenario may explain how certain strains of enterococcus, which kill more than 20,000 people each year in the United States, have become resistant to the powerful antibiotic vancomycin.

But not everyone agrees that the working group is on the right track. The link between resistance in harmless bacteria--particularly those in animals--and human pathogens is "pretty tenuous," says Richard Carnevale, director of regulatory affairs at the Animal Health Institute, an industry group that represents producers of animal antibiotics. "I'm not sure [the tracking effort] is worth doing." But Fred Angulo, a CDC epidemiologist, welcomes the new group's efforts. Says Angulo: "We need to focus attention on every area where antibiotics are used."

Posted in Biology