Antibiotic-Resistant Strain of Bacteria Renews Fears of Superbug Arrival in the US

The strain did not seem to respond to a last-resort drug, a study said.

— -- Federal health officials are sounding an alarm today, revealing that researchers may have uncovered a strain of bacteria so resistant to treatment that some of the toughest antibiotics cannot kill it.

Bacteria found in a Pennsylvania woman suffering from a urinary tract infection was found to be resistant to the antibiotic called colistin, according to a case report released today in Antimicrobial Agents and Chemotherapy.

The strain of bacteria was isolated from her urine. Colistin is considered a last-resort antibiotic for bacteria that does not respond to medication. It is rarely used because of its harsh side effects.

“The more we look at drug resistance, the more concerned we are,” said Dr. Tom Frieden, the head of the U.S. Centers for Disease Control and Prevention. "It basically shows us that the end of the road isn't very far away for antibiotics."

CDC officials did clarify however that in this woman's case, the bacteria strain was susceptible to a more commonly used antibiotic, making the use of colistin for treatment unnecessary.

"The strain is not resistant to everything. It carries the plasmid [genetic material] for colistin resistance," said Dr. Beth Bell, director of the CDC's National Center for Emerging and Zoonotic Infectious Diseases and the person overseeing antibiotic resistance. "The fear is that this could spread to other bacteria and create the bacterium that would be resistant to everything."

For years, officials have been concerned that antibiotic-resistant bacteria could develop and not be affected by a known antibiotic. There are only a few classes of antibiotics to treat bacterial infections to begin with, experts say.

The overuse of antibiotics by people and in animals has bred superbugs, resistant strains of bacteria. A lack of good infection control has helped them spread in hospitals. According to the CDC, there were 2 million antibiotic resistant infections in 2013.

"The medicine cabinet is empty for some patients," Frieden said. "It is the end of the road for antibiotics unless we act urgently."