More than 30 years ago, the U.S. Food and Drug Administration acknowledged that the unnecessary use of huge quantities of antibiotics in livestock feed for animals intended for human consumption could contribute to the rise in potentially fatal antibiotic-resistant superbugs. This finding led the agency to issue a petition calling for the withdrawal of certain drugs in feeds that may serve as a reservoir of antibiotic-resistant pathogens and nonpathogens ... [that] can produce human infections.

That was in 1977. Only days before last Christmas, the FDA withdrew via an obscure posting in the Federal Register two long-stalled Notice of Opportunity for a Hearing requests to ban both penicillin and tetracyclines in animal feeds. The agency declared it would focus on encouraging voluntary reform within the agricultural industry instead of enforcing regulatory action, a move that was derided by critics who pointed out the industry had decades to change its ways, to no avail.

However, the industry may now be forced to change its ways by court order.

On Thursday, a judge ordered the FDA to begin proceedings to withdraw approval for the nontherapeutic use of penicillin and tetrayclines in animal feed, ruling that the agency should have followed through with that action once it acknowledged those antibiotics were potentially hazardous back in 1977.

This is one of the biggest advances on the issue in the 35 years. It's a huge public-health victory, said Avinash Kar, an attorney with the Natural Resources Defense Council, one of the plaintiffs in the lawsuit that was being addressed in court on Thursday.

The FDA will likely hold a hearing for drug manufacturers to give them an opportunity to prove the use of those antibiotics in livestock feed is not dangerous to human health. Their potential for success is unlikely, according to Kar, who contended the court decision acknowledged that mounting scientific evidence proves the continued use of those drugs in livestock can lead to the development of antibiotic-resistant superbugs.

Research has shown that the use of antibiotics in livestock leads to the development of antibiotic-resistant bacteria that can be -- and has been -- transferred from animals to humans through direct contact, environmental exposure, and the consumption and handling of contaminated meat and poultry products, states the court order.

Scientists Have Noted Potential For 'Superbug' Development Since The 1960s

The agricultural industry began administering livestock feed with small doses of antibiotics in the 1950s, not to treat sick animals, but to ward off bacteria that animals would typically expend energy on to fight off naturally. Consistently consuming low levels of antibiotics allows livestock -- primarily cattle, pigs, chickens, and turkeys -- to fatten faster and more efficiently, from a producer's perspective.

The practice is often used by large-scale factory farmers, many of which keep their livestock in unsanitary living conditions that result in higher levels of the bacteria the antibiotics are supposed to combat. Scientific literature dating from the 1960s has connected the emergence of sometimes-lethal antibiotic-resistant bacteria with these actions, and new reports from agencies such as the World Health Organization, the American Medical Association, and the Infectious Diseases Society of America continue to document the connection.

The consequences have already been apparent. For instance, a report in the April 2011 edition of Clinical Infectious Diseases found that nearly one-half of 136 samples -- coming from 80 different brands -- of beef, turkey, pork, and chicken from grocery stores across the country were contaminated with multidrug-resistant strains of Staphylococcus aureus, a bacteria that has been linked with the development of rashes, sepsis, and pneumonia.

Following a slew of salmonella outbreaks that occurred last summer, a coalition of medical and public-health groups last September warned federal authorities, including the FDA and the U.S. Centers for Disease Control and Prevention, that the evidence is so strong of a link between misuse of antibiotics in food animals and human antibiotic resistance that FDA and Congress should be acting much more boldly and urgently to protect these vital drugs for human illness.

In 2009, the FDA itself reported that about 70 percent of all antibacterial drugs in the United States were sold for use in livestock animals to promote growth, prevent disease, and treat illnesses caused by unsanitary conditions.

What Comes Next?

While the court's decision is certainly something to celebrate, Kar said it could take months or even years for the FDA to actually institute the ban on penicillin and tetracyclines.

The fight is far from won, but this is an important victory that puts us on the right path, Kar said.

So what comes next? More litigation.

Kar said that, in addition to a hearing for drug manufacturers, further court proceedings most likely would be necessary to establish a solid timeline for the FDA to act on the court's decision. Moreover, the FDA could always appeal the decision, a move that would delay action even longer.

The NRDC is currently awaiting the next stage of court proceedings regarding the FDA's denial of two citizens' petitions that were filed in 1999 and 2005 calling for the agricultural industry to suspend the unnecessary use of all antibiotics in healthy animals. Last November, the agency denied both petitions, without explanation.

That decision could be particularly impactful since it calls for the regulation of antibiotics other than penicillin and tetracyclines. Although those drugs currently constitute about 50 percent of the antibiotics used in livestock, there are several other antibiotics also in use, according to the FDA.

Kar said a briefing on that lawsuit will be completed by April 16.

These drugs are intended to cure disease, not fatten pigs and chickens, he said.