Canada Geese May Spread Antibiotic-resistant Superbugs

There's a newly-discovered "vector" in the transmission of infectious bacteria: birds. The CDC studied Canada geese in Geogia and North Carolina, and found the birds were picking up and spreading antibiotic-resistant E. coli and salmonella bacteria from nearby pig farms.

More detail from a CBC News report:

Geese from a North Carolina flock that often lingered near a pig farm had particularly high levels of the superbugs – and often showed resistance to more than one antibiotic, the researchers found.

Pig farms, like other livestock-rearing operations, can use high levels of antibiotics to tamp down diseases.

"Some of these geese were landing in a lagoon that had some run-off from a pig operation," said Dr. Scott Weese, of the Ontario Veterinary College in Guelph.

"So presumably there was resistance in E. coli from some of the pigs. The geese landed in the environment and through just normal eating or grooming in that environment, they ingested the E. coli."

Although the flocks observed were non-migratory, the U.S. study – posted on the CDC's Emerging Infectious Diseases website – concludes that Canada geese could spread the pathogens.

"This species could serve to disperse bacteria between widely separated locations," warned the study, to be published in the June issue of the Journal of Emerging Infectious Diseases.

"In addition, since these birds use farm ponds and waste lagoons and graze on pastures inhabited by cattle and other livestock, the opportunities exist for new health problems in wildlife populations to emerge."

Here's the final graf from the conclusions of the CDC study:

This and other studies suggest that resident, free-living, and migratory birds can be potential vectors of zoonotic pathogens, including antimicrobial-resistant variants, between waste-handling facilities and other agricultural resources, such as crops and water. Although all of our study populations of Canada Geese were nonmigratory, this species could serve to disperse bacteria between widely separated locations. In addition, since these birds use farm ponds and waste lagoons and graze on pastures inhabited by cattle and other livestock, the opportunities exist for new health problems in wildlife populations to emerge as well as new reservoirs of zoonotic disease to form. This work is the basis of continuing efforts to examine the potential role of wildlife in agricultural habitats as vectors of antimicrobial resistance in the environment.