Jun 1, 2016 11:22 AM EDT Health  An official with the Centers for Disease Control and Prevention says there's no reason for people to be overly concerned, right now, about the discovery in a Pennsylvania woman of an infection that's resistant to one of the world's "last-resort" anti-bacterial drugs, CBS Philadelphia reported.  The Pennsylvania woman is the first person in the country to be infected with bacteria containing a gene that makes it resistant to colistin, a so-called "last-resort" antibiotic.  But on a conference call with reporters, Dr. Beth Bell of the CDC said individuals, at this point, shouldn't fret too much about it.  "The risk to the public, at this point, is really pretty much minimal. There are things that people can do to protect themselves against resistant bacteria," she said. Those things include frequent hand washing and making sure food is thoroughly cooked to kill contaminants like E. coli.  Citing privacy laws, Bell and other officials could provide little information about the infected woman.  The CDC points out that the Pennsylvania State Health Department investigation has determined that the woman was infected with a strain of E. coli -- not the superbug known as CRE -- and the bacteria was not resistant to all antibiotics.  But officials acknowledge that the gene's presence and its ability to share its colistin resistance with other bacteria raise the risk that bacteria resistant to all antibiotics could develop.  The CDC plans to beef up laboratory response to the situation. Currently, the investigation is focused on identifying close contacts, including household members and healthcare workers, of the Pennsylvania patient to see if any of them may have been at risk for transmission of the bacteria containing the colistin-resistant gene.  © 2016 CBS Interactive Inc. All Rights Reserved.
After a Pennsylvania woman was infected with bacteria resistant to "last resort" antibiotics, officials weigh in on how much people should worry