Organic methods reduce antibiotic-resistant germs

Posted by Christine, August 14, 2011

Results of a new study show that poultry raised on farms that have shifted to organic practices have significantly lower levels of antibiotic- and multi-drug resistant enterococci bacteria.

Use of antibiotics in conventional animal food production has been linked to the rise in strains of disease-causing bacteria that are resistant to one or multiple antibiotics. The results suggest that removing antibiotic use from large-scale poultry farms in the US “can result in immediate and significant reductions in antibiotic resistance for some bacteria,” according to “Lower Prevalance of Antibiotic-resistant Enterococci on U.S. Conventional Poultry Farms that Transitioned to Organic Practices,” published in the August 10 online edition of Environmental Health Perspectives.

We initially hypothesized that we would see some differences in on-farm levels of antibiotic-resistant enterococci when poultry farms transitioned to organic practices. But we were surprised to see that the differences were so significant across several different classes of antibiotics even in the very first flock that was produced after the transition to organic standards, explained Dr. Amy R. Sapkota, the study’s lead researcher, an assistant professor with the Maryland Institute for Applied Environmental Health. “It is very encouraging.

The scientists found that 67% of Enterococcus faecalis obtained from poultry from conventional poultry farms were resistant to the antibiotic erythromycin, while only 18% of the bacteria from newly organic poultry farms were resistant to it. Significant differences were also found in levels of multi-drug resistant bacteria – organisms resistant to three or more antimicrobial classes, according to the report.