Cutting off energy supply cripples resistant bugs

Last Updated: Tue, Feb 12, 2013 10:00 hrs

Washington, Feb 12 (IANS) Rice University researchers crippled a bug's ability to resist antibiotics by cutting off its energy supply, gaining the upper hand against such pathogens.

Rice environmental engineer Pedro Alvarez and his team managed to neutralise Pseudomonas aeruginosa micro-organism's ability to resist the antibiotic tetracycline, by limiting its access to food and oxygen, the sole source of its energy.

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 journal Environmental Science and Technology reports.

The results are the latest in a long effort to understand the environmental aspects of antibiotic resistance, which threatens decades of progress in fighting disease, according to a Rice statement.

"The propagation of antibiotic resistance has been perceived as a medical or microbiology-related problem," Alvarez said.

"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."

"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 the soil, and E. coli, which carries resistant genes directly from animals through their faeces into the environment.

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