Soap and Livestock Feed in FDA's Sights as Antibiotic Resistance Looms

Gerald Clarke

If someone were to sit down and design a gigantic, industrial-scale, open-air experiment to reduce the effectiveness of our antibiotics, they might be wasting their time, because agribusiness is already conducting it.

Through processes that are still unknown, including antibiotics in the feed of livestock helps the animals gain weight faster. It is standard practise throughout the whole industry. The problem is that some of the classes of antibiotics used for this process are the same that are employed to combat infectious diseases in humans. Their use in livestock then for non-medicinal reasons increases the probability of antibiotic resistant bacteria. These bacteria don’t even have to be pathogens or infect humans to cause harm, as bacteria can pass genetic information between them (even between species) in a process called horizontal transfer.

Senior figures have been highlighting the danger posed by antibiotic resistance recently; with Dame Sally Davis describing it is a “ticking time bomb”. The FDA has taken action with guidance on antibiotic use being issued under the optimistic title of ‘Phasing Out Certain Antibiotic Use in Farm Animals.’

The guidance aims to reduce the amount of important antibiotics used to increase livestock growth. Under the guidance these antibiotics could only be used to treat illnesses or under prescription from a veterinarian. One of the criticisms that people have levelled at the scheme is that it is entirely voluntary, however the FDA claim on their website that it is the “fastest, most efficient way to make these changes.”

In a separate, but related move, the FDA has proposed a rule which could require the manufacturers of antibacterial soaps to provide more evidence of their effectiveness and their safety. As well the danger of widespread use of these soaps pushing bacteria towards antibacterial resistance, there is some evidence that they interfere with normal hormone signalling. Although these antibacterial soaps may indeed kill bacteria, with this new evidence, the worry is that the risks outweigh the benefits. The FDA has opened itself to comments on the rule and consultation will remain open for six month period and the proposed rule would come into force in 2016.

Both of these moves show a willingness on the part of the FDA to begin to tackle problem use of antibiotics and antibacterials. Widespread employment of useful agents for low risk purposes may have benefits in the short term, but with a dangerous lack of other options, if these should fail, the results could be catastrophic. More efforts like these could certainly help to stem the tide of resistance, but with few good antibiotic candidates in development, the long term picture is less clear.