More than 50 years ago, the U.S. Food and Drug Administration (FDA) approved the addition of antibiotics to livestock feed to reduce disease that can occur from dense living conditions and high-protein diets. Yesterday, the FDA announced its aim to withdraw that approval and stop all nontherapeutic germ-fighting in chickens, pigs and cows.

The ban would cover seven classes of antibiotics that the FDA considers “highly” or “critically” important components of the human arsenal against bacteria. “Trends toward increasing numbers of infection and increasing drug resistance show no sign of abating,” Joshua Sharfstein, principal deputy commissioner of the FDA explained in written testimony to the House of Representatives' Committee on Rules.

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The growing prevalence of drug-resistant tuberculosis is a "potentially explosive situation," the World Health Organization's director general, Margaret Chan, said today at the opening of a three-day meeting on the problem.

Representatives from 27 countries affected by multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) are gathering in Beijing to discuss how to address the trend. MDR-TB is resistant to first-line drugs; XDR-TB doesn’t respond to those meds or second-line therapies. More than 500,000 MDR-TB cases occur annually—only 3 percent of them treated according to WHO standards—and XDR-TB exists in more than 50 countries, the agency says. People with HIV, whose immune systems are already weakened by the AIDS-causing virus, are at increased risk of TB.

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Curing tuberculosis that's resistant to the most commonly used, first-line drugs is a growing problem, with an estimated half million people worldwide now infected with so-called MDR (multi-drug resistant) TB. Of those, an estimated 50,000 have extensively drug-resistant (XDR) strains that don't respond to more potent drugs, either. Now scientists say they've hit upon a potential breakthrough: an antibiotic previously dismissed as useless against TB killed 13 resistant strains of the bacteria in the lab when it was combined with another drug.

The finding, published today in Science, has yet to be tested in people, study co-author John Blanchard, a biochemistry professor at Albert Einstein College of Medicine in New York, tells ScientificAmerican.com. But in a Petri dish, the meds, meropenem and clavulanate, destroyed and stopped the replication of the resistant TB bacteria, cultured from mucus samples from South Korean patients.

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Giving antibiotics to patients in hospital intensive care units (ICUs) to prevent—rather than fight—bacterial infections may reduce the number of patient deaths, Dutch scientists report today in The New England Journal of Medicine. Despite the findings, some researchers remain skeptical whether the possible risks (most notably spurring new antibiotic-resistant germs) outweigh the benefits of plying patients with antibiotics instead of using other more benign strategies such as hand-washing, isolating contagious patients and scrubbing hospitals with antiseptic cleansers.

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