Common Herbicides Linked to Antibiotic Resistance

Washington, DC–(ENEWSPF)–March 30, 2015. Last week, following the World Health Organization’s (WHO) declaration that glyphosate is carcinogenic to humans based on animal studies, a new study was published in the American Society of Microbiology’s journal, mBio, linking glyphosate, 2,4-D and dicamba to antibiotic resistance after testing the sub-lethal effects of these pesticides in certain bacteria.

The new mBio study finds that when bacteria, specifically Salmonella and E. coli, are exposed to the herbicides described above, they responded differently to the common antibiotics ampicillin,

ciprofloxacin, chloramphenicol, kanamycin, and tetracycline. Researchers replicated real-world scenarios by purchasing weed killers from a local store and using the exact levels that are specified on the product label. This provided researchers with the opportunity to observe how the bacteria reacted when exposed to the herbicides at sublethal levels; that is, those that did n0t kill them. When the bacteria are exposed to the herbicides and the antibiotics at the same time, the exposure to the herbicides trigger a defense mechanism that otherwise would not have been triggered solely by the antibiotics. This defense mechanism seeks to rid the bacteria of toxins and is non-specific, which means while it builds resistance to the toxic effects of the herbicides, it also builds resistance to the antibiotics, creating antibiotic-resistant strains that otherwise may not have occurred.

Read more here: Common Herbicides Linked to Antibiotic Resistance.