Is the Golden Age of Antibiotics Coming to an End?

Researchers have uncovered two cases of U.S. patients infected with bacteria carrying an antibiotic-resistance gene, a troublesome development in the eyes of scientists and health care officials. The new findings feed a growing fear that today's faltering antibiotics will leave even the developed world defenseless against increasingly resistant "superbugs."

"The golden age of antibiotics appears to be coming to an end," writes health reporter Melissa Healy in the L.A. Times. She cites research showing that 70% of Americans are unaware of the growing danger posed by highly resistant pathogens. "It's a slow catastrophe," said Colonel Emil Lesho, director of the Multidrug-resistant Organism Repository and Surveillance Network (MRSN), to Healy.

When the British biologist Alexander Fleming discovered penicillin in 1928, he ushered in an age of modern medicine equipped with the "wonder drugs" it needed to fight the spread of many bacteria-borne illnesses, including tuberculosis, syphilis, diphtheria and even leprosy. But it was not long after the advent of mass-produced antibiotic agents that medical workers began to encounter drug-resistant strains of bacteria.

Over time, more and more antibiotic medicines have lost their "wonder drug" status as an increasing number of resistant "superbugs" has emerged. But health workers have always been able to rely on colistin - a medicine that is toxic to the human kidney, but nevertheless the avenue of last hope to many a desparate patient.

Now, that hope is dying. On May 18, MSRN scientists at the Walter Reed Army Institute of Research analyzed a sample of E. coli bacterium taken from a Pennsylvanian woman and found that its DNA possessed the mcr-1 gene, which makes the microbe untreatable with colistin.

On July 11, JMI Laboratories researchers published a study that revealed a second U.S. case of infection by an E. coli bacterium carrying the mcr-1 gene. The "superbug" was detected in a year-old sample from a patient in New York.

Science Daily reports that the lab team is investigating whether the mcr-1 gene discovered might be plasmid-mediated, a serious concern because "plasmids, genetic elements that are independent of the host genome, often jump between different bacterial species, spreading any resistance genes they carry."