Study to investigate whether antibiotic resistance bacteria, genes being discharged in wastewater effluent

SCCWRP is collaborating with its member agencies to design a study examining 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 early next year, will measure the prevalence of antibiotic-resistant bacteria entering wastewater treatment plants across Southern California, and the types of bacteria and genetic material surviving treatment and being discharged into the environment.

Researchers are particularly concerned about 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 the environment. Once in the environment, potentially pathogenic bacteria in the environment can take up the antibiotic resistance genes, which could confer antibiotic resistance to bacterial strains that can make humans sick.

Prior 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.

The SCCWRP-facilitated study will involve participation by seven wastewater treatment plants in Los Angeles, Orange and San Diego Counties, which will screen both influent and effluent samples for a range of antibiotic-resistant bacteria and antibiotic resistance genes. Sampling will take place once a quarter for a year.

Study participants are meeting over the next few months to finalize sampling dates and schedule training for lab personnel.