A century ago, an ear infection could have meant deafness; a staph infection could have meant death. Those days may seem long gone. But scientists warn that drug resistance could be our Achilles heel. "Just about every pathogen that causes human disease is becoming resistant to the drugs we rely on most to treat them," says David Bell, the CDC's antimicrobial resistance coordinator. Everything from malaria to bacteria lurking in leftovers is getting harder to kill. Here, five top offenders.

POISON POULTRY: Campylobacter jejuni