NEW HAVEN, Conn. (AP) — Bacteria lodged deep in Ella Balasa's lungs were impervious to most antibiotics. At 26, gasping for breath, she sought out a dramatic experiment — deliberately inhaling a virus culled from sewage to attack her superbug.

"I'm really running out of options," said Balasa, who traveled from her Richmond, Virginia, home to Yale University for the last-resort treatment. "I know it might not have an effect. But I am very hopeful."

Pitting one germ against another may sound radical, but it's a sign of a growing global crisis. Increasingly people are dying of infections that once were easy to treat because many common bugs have evolved to withstand multiple antibiotics. Some, dubbed "nightmare bacteria," are untreatable. Now scientists are racing to find novel alternatives to traditional antibiotics, a hunt that is uncovering unusual ways to counter infection, in unusual places.