The research into herbicides comes from the University of Canterbury. Researchers have discovered as bacteria are exposed to common herbicides, the organisms develop resistance to antibiotic drugs. The rates of developing resistance appear to many thousands of times more rapid than with bacteria not exposed to these types of chemicals.
Antibiotic resistance can occur as a result of genotypic diversity (arising from a mutation or horizontal gene transfer), or from differences in gene expression due to environmental variation (adaptive resistance). Resistance also increases the cost of health care with lengthier stays in hospital and more intensive care required.
The new research points to the use of herbicides such as Roundup (glyphosate) and Kamba (dicamba), as used in large-scale agriculture, can affect bacteria to the extent that they are likely to develop mechanisms to become resistant to antibiotics.
Speaking with Laboratory Roots, chief researcher Jack Heinemann said: “The combination of chemicals to which bacteria are exposed in the modern environment should be addressed alongside antibiotic use if we are to preserve antibiotics in the long-term.”
The research did show that herbicides can enhance the toxic effects of antibiotics, it was also demonstrated that herbicides also increase the rate by which bacteria acquire antibiotic resistance. This is due to the active ingredients in the herbicides and was concentration dependent.
The effects were noted with Escherichia coli and Salmonella enterica, although the effects did depend upon antibiotic was selected.
Reported by Phys.org, Professor Heinemann adds: “We are inclined to think that when a drug or other chemical makes antibiotics more potent, that should be a good thing. But it also makes the antibiotic more effective at promoting resistance when the antibiotic is at lower concentrations, as we more often find in the environment…Such combinations can be like trying to put out the raging fire of antibiotic resistance with gasoline.”
Further research is required to assess to what extend other different manufactured chemicals may contribute to this effect.
This research has been published in the journal PeerJ. The research paper is titled “Agrichemicals and antibiotics in combination increase antibiotic resistance evolution.”
