It's been almost a century since the discovery of penicillin kicked off the era of antibiotics. Over the decades, the germ-killing drugs have saved millions of lives by making it possible to eradicate tuberculosis, pneumonia and other bacterial infections that had been scourges for millennia.

But a complex phenomenon known as antibiotic resistance is now sapping the drugs' curative power. Research has shown that taking an antibiotic can cause infectious bacteria in the body to develop resistance to antibiotics; these drug-resistant germs can trigger subsequent infections that are hard to treat successfully — and spread such drug-resistant infections to others.

Experts say the problem is compounded by improper use of antibiotics by doctors, hospitals and patients, as well as by farmers and others in the agricultural sector (the drugs are commonly administered to livestock, as well as to humans).

Antibiotic resistance now poses an urgent threat in the United States and around the world. Certain skin infections, sexually transmitted diseases, urinary tract infections and other ailments that once could easily have been eradicated with common antibiotics are now resistant to multiple drugs. Some "superbug" infections are resistant to all antibiotics — meaning that effective, and potentially life-saving treatment, is no longer possible.

"We're in a tough situation because of the increasing likelihood that each time you or I develop an infection that is resistant, we will have very limited [treatment] options or no options at all," says Lauri Hicks, director of the office of antibiotic stewardship at the Centers for Disease Control and Prevention in Atlanta. "Not only are we more likely to end up in the hospital, we're more likely to have a lengthy illness. Even if we survive the illness, then we're more likely to have long-term consequences."

What can be done to curb the problem? What can doctors, hospitals and patients do? How about government officials and the agricultural sector? And what's the appropriate role for pharmaceutical manufacturers working to develop new germ-killing drugs?

Hicks and three other experts on antibiotic resistance explored these and other questions in a panel discussion held in Boston on Friday.

The other panelists were Marc Lipsitch, a professor of epidemiology and the director of the Center for Communicable Disease Dynamics at the Chan School in Boston; Helen Boucher, a professor of medicine at the Tufts University School of Medicine in Boston and the director of the Tufts Center for Integrated Management of Antimicrobial Resistance; and Kevin Outterson, a professor of law at Boston University and executive director of Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator.

The panel was moderated by David Freeman, editorial director of NBC News MACH. Freeman has moderated a series of panels at the Chan School, including ones on self-driving cars and gene editing.

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