Drug-resistant superbug: What you need to know now

Health officials are reporting the first U.S. case of a human infected with a  “superbug” – a drug-resistant infection that leaves it victims with few, if any, options for treatment.

According to the Centers for Disease Control and Prevention, a 49-year-old woman Pennsylvania woman was diagnosed with a rare strain of E. coli that proved to be something called plasmid-mediated colistin resistance, or mcr-1.

Here's a quick look at the "superbug" and what mcr-1 is.

What is mcr-1?

Mcr-1 is a colistin-resistance gene. What that means is that the strain of E. coli the woman contracted carries a gene on a portion of DNA called a plasmid. The plasmid passes along that gene -- mcr-1 -- making more of the bacterium in her body resistance to antibiotics.  This is especially concerning since colistin is considered a drug of last resort -- one used when other antibiotics fail.

How did she get mcr-1?

That is not known right now. The woman has not traveled outside of the United States during the past five months, according to the CDC.

Why can’t dugs kill it?

Antibiotic resistance happens if the bacterium change and are able to fool the antibiotic by “hiding” or by pushing the drug out of the cell. Some bacterium simply destroy the antibiotic. She was treated with other antibiotics that did kill the infection.

What are the symptoms?

The symptoms vary depending on where in your body the infection is located.

How common is it?

It is rare, the Pennsylvania case is the first recorded case in the United States.  Cases have been seen in humans and pigs in China and in Canada, Africa, Europe and South America.