Strikingly, they even found bacteria resistant to streptomycin, a common human antibiotic that is rarely used in poultry and was not used on the farms the researchers studied.
Bacteria swap genes relatively easily, and Lee explained that the concern is that drug resistance genes from bacteria that infect poultry could be passed on to bacteria that cause human illness. With these resistance genes, human bacterial illness could become harder to treat.
These concerns led the European Union to ban the use of antibiotics for growth promotion in chickens in 2006. In 2005, the U.S. Food and Drug Administration banned the use of the drug Baytril ?the brand name for enrofloxacin, a fluoroquinolone antibiotic ?in poultry, citing concerns that it could lead to resistance in human antibiotics such as Cipro, also a fluoroquinolone.
Several advocacy groups are pushing for a more comprehensive animal antibiotic ban in the United States, but Lee said her research plus the evidence from the Baytril ban suggests that approach won't help.
"They banned Baytril in 2005, and if you look at Baytril resistance in campylobacter now it's essentially unchanged," Lee said.
In previous studies, Lee has tried to recreate experimentally conditions that should lead to the swapping of resistance genes among bacteria. Lee said these events ?known as the horizontal transfer of genes ?do occur, but they may not be as common as initially thought.
What may be driving the antibiotic resistance that Lee has observed in her studi
Source:University of Georgia