Rice University researchers "cured" a strain of bacteria of its ability to resist an antibiotic in an experiment that has implications for a long-standing public health crisis.
Rice environmental engineer Pedro Alvarez and his team managed to remove the ability of the Pseudomonas aeruginosa microorganism to resist the antibiotic medication tetracycline by limiting its access to food and oxygen.
Over 120 generations, the starving bacteria chose to conserve valuable energy rather than use it to pass on the plasmid a small and often transmissible DNA element that allows it to resist tetracycline.
The researchers' results, reported this month in the American Chemical Society journal Environmental Science and Technology, are the latest in a long effort to understand the environmental aspects of antibiotic resistance, which threatens decades of progress in fighting disease.
"The propagation of antibiotic resistance has been perceived as a medical or microbiology-related problem," Alvarez said. "And it truly is a serious problem. But what many people miss is that it is also an environmental pollution problem. A lot of the antibiotic-resistant bacteria originate in animal agriculture, where there is overuse, misuse and abuse of antibiotics."
Alvarez contended that confined animal feeding operations (CAFOs) are potential sources of environmental contamination by antibiotics and the associated antibiotic-resistant genes that find their way into the ground, water and ultimately the food supply.
"We started with the hypothesis that microbes don't like to carry excess baggage," he said. "That means they will drop genes they're not using because there is a metabolic burden, a high energy cost, to keeping them."
The Rice researchers tested their theory on two strains of bacteria, P. aeruginosa, which is found in soil, and E. coli, which carries resistant genes directly from animals throu
|Contact: David Ruth|