Cummings Lab Research

Urban Wetlands as Reservoirs of Antibiotic Resistance

Antibiotic resistance poses a growing public health threat, yet the mechanisms underlying this phenomenon remain unclear. In our lab, we study the role of urban storm water in spreading antibiotic-resistant bacteria and, more importantly, antibiotic resistance genes in natural environments where they may re-enter the human community. Our research shows that genes encoding resistance to clinically important antibiotics (e.g., Cipro) wash into California's coast during winter rains and persist at low, but detectable, levels into the dry summer months. Most of these genes are encoded on small pieces of DNA called plasmids that are readily shared among bacteria that come into contact with one another. Thus, the release of plasmid-encoded antibiotic resistance genes into the environment may lead to an overall increase in antibiotic resistance among both environmental and clinical bacteria.