Glyphosate takes another hit: Herbicides may lead to antibiotic resistance

| | March 27, 2015

This has not been a good week for glyphosate, the active ingredient in Roundup and other herbicides. On Friday, the World Health Organization (WHO) announced that it had classified glyphosate, the United States’ most widely-used pesticide, as “probably carcinogenic to humans.”

Now, the chemical has another strike against it. A study published today by the American Society of Microbiology’s journal mBio has linked glyphosate and two other widely-used herbicides–2,4-D and dicamba–to one of the most pressing public health crises of our time: antibiotic resistance.

This study found that exposure to these herbicides in their commercial forms changed the way bacteria responded to a number of antibiotics, including ampicillin, ciprofloxacin, and tetracycline–drugs widely used to treat a range of deadly diseases.

Dicamba, 2,4-D, and glyphosate have been in use for decades, so why have their antibacterial-resistance effects not been documented before? As the study’s lead author, Jack Heinemann, professor of genetics at the University of Canterbury in New Zealand, explains, when pesticides are tested for adverse effects, “it’s the lethal toxicity that people focus on.” In other words, how much of the chemical will kill an organism.

Related article:  Facing deadline, farmer backlash, EU reauthorizes herbicide glyphosate for 18 months

“What makes our study different, is that it is looking at a sub-lethal effect,” says Heinemann. “The effect we see requires that the bacteria stay alive.”

Scientists know that overuse of antibiotics in humans can decrease their effectiveness. In the same way, says Heinemann, “exposure to these pesticides make the pathogens stronger.”

Also to consider is the approval earlier this year of a new pesticide that combines glyphosate and 2,4-D and soybean and cotton seeds genetically engineered to resist dicamba, all of which are expected to increase use of these pesticides.

Read full, original article: Study Links Widely Used Pesticides to Antibiotic Resistance

The GLP aggregated and excerpted this article to reflect the diversity of news, opinion, and analysis. Click the link above to read the full, original article.

6 thoughts on “Glyphosate takes another hit: Herbicides may lead to antibiotic resistance”

  1. no surprise: nature (including microbes and viruses) always find a better way to superate the obstacles that humans and animals put to block them; and the cost of using more and more artificial chemical molecules will increase, leading to more dependency of the farmers to Monsanto & co products… and banks. Simple, but stupid

  2. Whoops! Any amounts of glyphosate – allowed in eggs and animal feed, then unwittingly used to reproduce vaccines – may lead to unpredictable consequences when using that material to grow vaccines injected into children. Thus the “Spectrum of Autism” …

    • I just read that Heinemann study. He uses herbicide formulations so in case of an effect you don’t know what caused it. His set up: two strains of bacteria, three herbicide formulations and five antibiotics used in different concentrations which vary between individual Experiments. To say the least: it’s chaotic and the results are all over the place. Out of 30 Graphs 8 Show increased antibiotic sensitivity, 7 are neutral, 15 Show increased sensitivity. It ‘s a study without any plausible working hypothesis of how herbicides in General should affect antibiotic resistance. It really reminds of that French study and the similarities don’t end here. Heinemann’s work was co-financed by Henry Rowlands so “independen science” will not stick.

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