Researchers Warn How Pesticides Are Secretly Growing Antibiotic Resistance
By Heather Callaghan, Editor
More emphasis needs to be placed on antibiotic stewardship…Otherwise, new drugs will fail rapidly and be lost to humanity.
The first team of researchers ever to discover that the world’s most popular pesticides and herbicides increase the antibiotic resistance crisis have conducted another study to prove once and for all a frightening truth we must respond to.
Researchers at the University of Canterbury in New Zealand have confirmed once again that active ingredients of the commonly used herbicides, Roundup, Kamba and 2,4-D (glyphosate, dicamba and 2,4-D, respectively), each alone cause antibiotic resistance at concentrations well below label application rates.
Professor Jack Heinemann of the School of Biological Sciences in UC’s College of Science said the key finding of the research was that “bacteria respond to exposure to the herbicides by changing how susceptible they are to antibiotics used in human and animal medicine.”
The herbicides studied are three of the most widely used in the world, Prof Heinemann said. They are also used on crops that have been genetically modified to tolerate them.
The effect was not seen at herbicide concentrations that are presently allowed for food (called Maximum Residue Limits, MRL). However, the effect was seen at concentrations well below those applied to plants (application rates). Therefore, the authors believe, the effect is most likely to arise in farm workers in rural areas and in children in urban settings who are exposed to herbicides, if they are also on antibiotics.
They are among the most common manufactured chemical products to which people, pets and livestock in both rural and urban environments are exposed. These products are sold in the local hardware store and may be used without training, and there are no controls that prevent children and pets from being exposed in home gardens or parks. Despite their ubiquitous use, this University of Canterbury research is the first in the world to demonstrate that herbicides may be undermining the use of a fundamental medicine – antibiotics.
We reported on their previous research that discovered the same effects of pesticides on antibiotic resistance. A Monsanto spokesman at the time responded that the research couldn’t determine whether it was the active ingredients or the surfactants used in pesticides that actually made antibiotic resistance worse.
This research is a response to Monsanto’s claims to prove once and for all that both the active ingredients in pesticides and the surfactants are responsible for contributing to antibiotic resistance.
So now the scientists have even more bad news:
In addition, the new paper finds that added ingredients (surfactants) that are commonly used in some herbicide formulations and processed foods also cause antibiotic resistance. An antibiotic resistance response was caused by both the tested surfactants, Tween80 and CMC. Both are also used as emulsifiers in foods like ice cream and in medicines, and both cause antibiotic resistance at concentrations allowed in food and food-grade products.
Commenting on the regulatory implications of his team’s findings, Prof Heinemann said: “The sub-lethal effects of industrially manufactured chemical products should be considered by regulators when deciding whether the products are safe for their intended use.”
This discovery has much wider implications that we will have to handle in a future article…
“The United States, for example, estimates that more than two million people are sickened every year with antibiotic-resistant infections, with at least 23,000 dying as a result. By 2050, resistance is estimated to add 10 million annual deaths globally with a cumulative cost to the world economy of US$100 trillion. In other words, roughly twice the population of New Zealand will be lost annually to antibiotic resistance,” said Prof Heinemann.
The biggest problem with our regulatory agencies is that they only study lethal or acute toxicity levels. They don’t focus on sub-lethal effects like how pesticides can kill ecologically important microbes. They focus on the effects of chemicals on humans and animals but not other organisms. Lastly, they do not consider the bigger picture such as cumulative and long-term effects of chemicals or what they do in combination.
Where this information is sought, it is usually only for people or animals. We are unaware of any regulator ever considering the risk of sub-lethal effects on bacteria. That is what makes this new research so important.
More emphasis needs to be placed on antibiotic stewardship compared to new antibiotic discovery. Otherwise, new drugs will fail rapidly and be lost to humanity.
Genetically engineered crops have increased the use of these pesticides. Pesticides aside, many have fears that the introduction of genetic engineering into the ecology will have grave ramifications. Norway, for instance, has banned GE salmon over fears of antibiotic resistance. And, earlier this year, an illegal GE bacteria found its way into an EU feedlot and it, too, was found to be resistant to antibiotics showing once again how reckless and unstable Big Biotech’s use of this technology really is.
DISCLAIMER: This article is not intended to provide medical advice, diagnosis or treatment.