Skip to main content
U.S. flag

An official website of the United States government

Gulls as sources of environmental contamination by colistin-resistant bacteria

March 10, 2020

In 2015, the mcr-1 gene was discovered in Escherichia coli in domestic swine in China that conferred resistance to colistin, an antibiotic of last resort used in treating multi-drug resistant bacterial infections in humans. Since then, mcr-1 was found in other human and animal populations, including wild gulls. Because gulls could disseminate the mcr-1 gene, we conducted an experiment to assess whether gulls are readily colonized with mcr-1 positive E. coli, their shedding patterns, transmission among conspecifics, and environmental deposition. Shedding of mcr-1 E. coli by small gull flocks followed a lognormal curve and gulls shed one strain >101 log10 CFU/g in their feces for 16.4 days, which persisted in the environment for 29.3 days. Because gulls are mobile and can shed antimicrobial-resistant bacteria for extended periods, gulls may facilitate transmission of mcr-1 positive E. coli to humans and livestock through fecal contamination of water, public areas and agricultural operations.

Publication Year 2020
Title Gulls as sources of environmental contamination by colistin-resistant bacteria
DOI 10.1038/s41598-020-61318-2
Authors Alan B. Franklin, Andrew M. Ramey, Kevin T Bentler, Nicole L Barret, Loredana M McCurdy, Christina Ahlstrom, Jonas Bonnedahl, Susan A. Shriner, Jeffrey C Chandler
Publication Type Article
Publication Subtype Journal Article
Series Title Scientific Reports
Index ID 70210283
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Biology WTEB