This article is more than 5 years old. Information may no longer be current.
Organic farming practices produced low levels of drug-resistant bacteria
Sapkota AR. Envir Health Pers. 2011. doi.org/10.1289/ehp.1003350.
Click Here to Manage Email Alerts
A lower prevalence for antibiotic-resistant and multidrug-resistant Enterococcus spp was observed among US poultry farms that transitioned to organic farming practices, according to new findings published in Environmental Health Perspectives.
“When the poultry farms transitioned to organic practices and ceased using antibiotics, we saw statistically significant declines in antibiotic-resistant and multidrug-resistant enterococci in the very first flock produced under organic standards,” Amy R. Sapkota, PhD, MPH, of the Maryland Institute for Applied Environmental Health, told Infectious Disease News.
Between March and June 2008, Sapkota and colleagues gathered poultry litter, feed and water samples from 10 conventional poultry houses and 10 newly transitioned organic poultry houses. The researchers tested all samples for Enterococcus and susceptibility to 17 antimicrobials.
“We chose to study enterococci because these microorganisms are found in all poultry, including poultry on both organic and conventional farms,” Sapkota said in a press release. “The enterococci also cause infections in human patients staying in hospitals. In addition, many of the antibiotics given in feed to farm animals are used to fight Gram-positive bacteria such as enterococci. These features, along with their reputation of easily exchanging resistance genes with other bacteria, make enterococci a good model for studying the impact of changes in antibiotic use on farms.”
The researchers found that all litter, feed and water samples isolated from both conventional and newly organic poultry houses tested positive for Enterococcus — the majority were extracted from poultry litter.
However, isolates from the organic poultry houses had significantly lower amounts of resistant E. faecalis (10%) and E. faecium(17%) vs. 42% multi-drug resistant E. faecalis and 84% multi-drug resistant E. faecium isolates from conventional poultry houses.
“While we know that the dynamics of antibiotic resistance differ by bacterium and antibiotic, these findings show that, at least in the case of enterococci, we begin to reverse resistance on farms even among the first group of animals that are grown without antibiotics,” Sapkota said.
Further research is planned for the next several years, according to Sapkota, to evaluate resistance over time and examine other microorganisms including Salmonella and Campylobacter. – by Ashley DeNyse
Disclosure: Dr. Sapkota reports no relevant financial disclosures.
The study was well performed using recognized methods and appropriate statistical data evaluation methods. Unfortunately, the average number of antimicrobials in the feed (three) and water (0.18) was not specified (which specific antimicrobials were given). Now it is impossible to draw conclusions concerning a specific compound and they all get the same verdict. Sapkota and colleagues provided a nice promotion for organic farming without any real improvement in anything. I'm still waiting to see a serious study showing the prevalence of clinical vancomycin/linezolid resistant E. faecium in those who consume organic vs. conventional poultry.
–Stefan Soback, PhD
Kimron Veterinary Institute, Beit-Dagan, Israel
Disclosure: Dr. Soback reports no relevant financial disclosures.
 |
Follow InfectiousDiseaseNews.com on Twitter. |