HARRISBURG, Pa. (WHTM) – Health experts say a 49-year-old Pennsylvania woman was found to have bacteria with a gene that makes it resistant to last-resort antibiotics.

According to a report published Thursday in the journal Antimicrobial Agents and Chemotherapy, the discovery of the plasmid-borne colistin resistance gene, mcr-1, is the first in the United States and “heralds the emergence of truly pan-drug resistant bacteria.”

A plasmid is a small piece of DNA that is not a part of a bacterium’s chromosome. Plasmids are capable of moving from one bacterium to another, spreading antibiotic resistance between bacterial species, according to the U.S. Department of Health and Human Services.

Colistin is used as a last-resort antibiotic to treat patients with multi-drug resistant infections.

Dr. Tom Frieden, director of the U.S. Centers for Disease Control and Prevention, told the National Press Club that “the medicine cabinet is empty for some patients.”

“It is the end of the road for antibiotics unless we act urgently,” he said.

The colistin-resistant gene was cultured last month at Walter Reed National Military Medical Center in Bethesda, Maryland. Doctors at an outpatient military treatment facility in Pennsylvania had submitted urine samples from the woman, who had symptoms of a urinary tract infection.

Federal health officials said they’re working to identify close contacts of the woman, including household and healthcare contacts, to determine whether any of them may have been at risk for transmission of the bacteria containing the mcr-1 gene.

Gov. Tom Wolf confirmed his administration has learned of a human case of mcr-1 in a Pennsylvania resident. He said the Department of Health is working closely with the U.S. Centers for Disease Control and Prevention and the Defense Department to “coordinate an appropriate and collaborative response between federal, state, and local entities.”

“We are taking the emergence of this resistance gene very seriously and we will take necessary actions to prevent mcr-1 from becoming a widespread problem with potentially serious consequences,” Wolf said in a statement. “The safety of Pennsylvanians is our utmost priority.”

The Health Department said it can’t discuss specific details of individual investigations because of the state’s Disease Prevention and Control Law. However, it said generally when the department conducts an investigation, it does the following:

interview the individual(s)

trace movement of individual(s), including travel history and medical facility transfers

interview family members and other close contacts of the individual(s)

facilitate collection of samples for testing

review medical records, if available, and interview health care providers, if any

work with local, federal and other state health agencies

interpret results and work with partners to prevent and control the spread of disease.

The Department of Health also said it cannot divulge specific information related to the individual.

“The discovery of the ‘superbug’ resistant to the antibiotics that are used when all others fail is cause for concern,” Dr. Scott Shapiro, president of the Pennsylvania Medical Society, said in a statement Thursday evening.

“But it’s important that we remember it was caught and now is not the time to panic as many healthcare professionals are working to address this situation,” he said.

The Associated Press reported the woman has recovered. CDC officials clarified the bacteria strain was susceptible to a more commonly used antibiotic, making the use of colistin unnecessary.

“The strain is not resistant to everything. It carries the plasmid for colistin resistance,” said Dr. Beth Bell, director of the CDC’s National Center for Emerging and Zoonotic Infectious Diseases. “The fear is that this could spread to other bacteria and create the bacterium that would be resistant to everything.”Get breaking news, weather and traffic on the go. Download the ABC27 News App and the ABC27 Weather App for your phone and tablet.