It’s the kind of scenario that might evolve in Hollywood: A college professor detects drug-resistance genes collecting in local wetlands, where they survive for weeks and are spread far and wide by seabirds.
But the discovery of extra-hardy DNA flourishing on the edge of San Diego isn’t science fiction. It’s the result of research by David Cummings, a microbiologist at Point Loma Nazarene University.
In the sewage-laced sediment of the Tijuana River Valley, Cummings and his students have uncovered an array of genes that help their bacteria hosts survive shots of penicillin, quinolines and other fundamental infection-fighting antibiotics. Over time, he fears the DNA could worm its way into bacteria that infect humans and undermine some of the world’s most widely prescribed medicines.
Think of the genes akin to living contaminants with an ability to spread and shuttle between bacteria.
“Genes that confer antibiotic resistance may in fact pose a more serious long-term public and ecosystem health threat than many pollutants in urban stormwater,” Cummings said. “From the perspective of public health, as soon as the coliforms disappear from the water column, everybody is happy. But the reality is there is this longer-term threat that is accumulating in the sediment.”