13 October 2006
Poultry Products Increase Antibiotic Resistance
A new three-year study claims to have established that antibiotic use as a livestock growth promoter increases the risk of human antibiotic resistance. The study, appearing in The Journal of Infectious Diseases, examined poultry exposure as a risk factor for antibiotic resistance in Enterococcus faecium, a gut bacterium that is increasingly the cause of infections in hospitals. The investigation team focused on use of a growth-promoting antibiotic, called virginiamycin, in poultry. Virginiamycin is closely related to quinupristin-dalfopristin, an antibiotic licensed to treat patients with serious, antibiotic-resistant infections.
"There is a relative lack of data on the impact of antibiotic use in livestock and its relationship to antibiotic resistance in humans, but there is a fair amount of indirect evidence suggesting that antibiotic use could pose a risk to human health," said researcher Edward Belongia, from the Marshfield Clinic Research Foundation.
"We've known for a long time that resistant bacteria can be found on retail poultry products, but our study is one of the first to show an association between human carriage of antibiotic resistance genes and eating poultry or handling raw poultry. These results indicate that virginiamycin use in poultry leads to transfer of antibiotic resistance genes to human gut bacteria through the food supply and they provide additional evidence that use of growth promoters in animals may have long-term consequences for human health," he added.
The FDA may now act on this information to improve its risk assessment procedures, particularly in light of a recent FDA Veterinary Medicine Advisory Committee meeting about an application to license a broad spectrum antibiotic, called cefquinome, for use in cattle.
Belongia said that there was concern in the medical community that cefquinome could promote resistance to cephalosporin drugs that are essential for many patients with serious or life-threatening infections. "At the end of the day, the FDA committee recommended against the drug. Our study focused on a different drug in a different type of animal, but this is a timely example of the controversy regarding the appropriate use of antibiotics in food-producing animals," he noted.
Source: Marshfield Clinic