Narrator: This is Science Today. Federal health officials have recently announced bacteria that cause serious illnesses such as pneumonia and meningitis are becoming increasingly resistant to antibiotics. Dr. Leland Rickman, an expert in infectious disease at the University of California, San Diego, says while this is alarming, it's not surprising.

Rickman: Bacteria from centuries ago have actually been discovered that are resistant to antibiotics even before we discovered them. So, it's nothing new for the bacteria to be able to produce antibiotics in their own right.

Narrator: What is new, is how quickly drug-resistant bacteria are evolving and outsmarting us.

Rickman: In the past, at least we've had the ability to develop new antibiotics to stay one or two steps ahead of some of these microorganisms. But with recent events over the last several years, it's obvious to me and to others that at some point, we are going to lose some antibiotics against certain infections that could potentially bring us back to the pre-antibiotic era.

Narrator: For Science Today, I'm Larissa Branin.