In June 2015,
Digital Journal reported about the presence of large numbers of antibiotics in wastewater. In research led by Professor Olya Keen, of UNC Charlotte it was argued that treatments to "clean up" wastewater could modify antibiotics and trigger an increase in antibiotic resistant bacteria.
Scientists based at Aalborg University, Technical University of Denmark have taken a different position. The researchers
have studied the genes, collected from wastewater treatment plants, that aid bacteria in developing antimicrobial resistance. Wastewater contains a mix of antimicrobial agents, discarded by people at home, pharmaceutical companies and hospitals, along with a variety of pathogenic bacteria. Many of these bacteria are — unsurprisingly given where much of the water comes from — found in the intestines of people.
The new findings show that treatment plants contain many genes that can potentially trigger resistance to a range of antimicrobial agents. While this poses a potential risk, studies indicate that these genes are only very rarely found in bacteria outside the wastewater treatment plants. This would suggest that water treatment plants are not a mechanism for passing on resistance genes to bacteria.
To verify the findings the researchers looked at five wastewater treatment plants in Denmark and took hundreds of samples. The samples were collected over a two year period.
The new research has been
reported to the journal
Nature Communications. The paper is titled “Limited dissemination of the wastewater treatment plant core resistome.”