Fears of gene pollution grow in TJ River
Los Angeles : CA : USA | May 03, 2012 at 6:32 PM PDT
Source: San Diego Union-Tribune
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.
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.
Dangerous Bacteria Found In Tijuana River Estuary
Discovery Made At Time Of Recent Sewage Spill
POSTED: 5:44 pm PDT April 27, 2012
UPDATED: 5:47 pm PDT April 27, 2012
SAN DIEGO — Researchers have found bacteria in the Tijuana River Estuary that could be hard to treat if someone is infected with the bacteria.
The discovery was made around the same time a computer malfunction at a Tijuana sewage treatment plant dumped 2.5 million gallons of sewage into the Tijuana River. That river crosses north into the United States and dumps into the Pacific Ocean. The spill forced the closure of beaches from Border Field State Park to Coronado.
“The most likely explanation for the presence of drug-resistance genes in the Tijuana watershed is that they are riding downstream in feces, then collecting in the muck. Over time, bacteria in the intestinal tracks of people, cows and other mammals that are treated with antibiotics can develop immunity to classes of commonly used drugs and pass through the body intact. Bacteria also have an unusual ability to swap DNA, meaning they are virtually impossible to control outside a laboratory.
Cummings’s concern is fueled by the fact that birds, waves and other vectors can pick up the bacteria and spread it to other spots where more people can come into contact with them. There’s no evidence that’s happened with drug-resistance genes locally. However, a 2010 study on gulls in Sweden concluded that bacteria of wild animals — with or without antibiotic-resistance traits — are a potential source of human infection.”