Study design being finalized to examine antibiotic-resistant bacteria, genes in effluent

SCCWRP and its POTW member agencies are finalizing the design of a study that will examine whether viable antibiotic-resistant bacteria and the genetic material that codes for antibiotic resistance are being discharged into the environment following the wastewater treatment process.

The study, scheduled to begin later this year, will measure the prevalence of antibiotic-resistance bacteria entering and exiting nine wastewater treatments across Southern California, including an international plant at the U.S.-Mexico border. Researchers will track which bacteria and genetic material survive
treatment and are discharged into receiving waters.

Researchers are focusing on antibiotic resistance genes in wastewater effluent because these genes may survive the treatment processes that destroy most bacterial cells, and then may travel via treated effluent into aquatic systems.

Once in the environment, bacteria in the environment can take up the antibiotic resistance genes, which could confer antibiotic resistance to them. If the bacteria being conferred antibiotic resistance include pathogens that make humans sick, it could be a health concern.

Previous studies have documented a broad array of antibiotic resistance genes in wastewater effluent, as well as how commonly bacterial cells swap their antibiotic resistance genes with one another.

Prior to the study’s launch, SCCWRP will be circulating standard operating procedures to all participating labs, so they can practice collection and analysis techniques and ensure they can generate high-quality, comparable results.