#04-159

Complete

Date Full Report Received

01/12/2006

Date Abstract Report Received

01/12/2006

Investigation

Institution:
Primary Investigator:

There is growing concern about the fate of antibiotics and antibiotic residues in the environment. These compounds can potentially have selective effects on bacteria, thus amplifying the resistance gene pool. The swine industry uses considerable amounts of certain antibiotics, such as tylosin and tetracycline. Although measured levels of these antibiotics in waterways associated with swine operations have been low, they may still be high enough to influence the persistence and dissemination of antibiotic resistance. The results of our studies suggested that the low levels of tetracycline observed in the waterways of the U.S. may not have a strong biological effect. In other words, these low tetracycline levels may not be high enough to select for antibiotic resistant bacteria and thus may not pose a threat to human or animal health through an increase in antibiotic resistant bacteria. The results of this study are based on laboratory experiments which may not mimic reality. Consequently, additional studies should be conducted in the field to validate the findings of this study. Ultimately, the results of these studies will help the swine industry manage the potential risks associated with the environmental release of antimicrobial compounds from farms.