Wastewater treatment systems are one of the few built environments where microbes get the attention we believe they deserve. Bacteria in particular are a critical component of treating the massive waste stream generated by humanity on a daily basis. And those bacteria are basically harmless out in the wild… unless they harbor and transfer antibiotic resistance genes acquired from the waste itself. And that’s exactly what appears to be happening according to a recent study. For a summary of the story try this article.
Basically here’s the story in a nutshell:
Humans take a bunch of antiobiotics
Those both create resistant bacteria in our bodies, as well as go into the waste stream where they can help select for resistance elsewhere.
Resistance can be transferred between organisms (“lateral gene transfer” or “horizontal gene transfer”)
Some of these resistant organisms are released out into the wild with the treated water, even after the very best treatment technology available.
And that’s where the study ends, showing that treated wastewater can be an important source of antibiotic resistance in otherwise pristine environments. The implication is then that this resistance can be transferred back to human pathogens and become part of the ongoing major health problem of antibiotic resistant pathogens.