Featured Research

from universities, journals, and other organizations

Poultry farms that go organic have significantly fewer antibiotic-resistant bacteria

Date:
August 11, 2011
Source:
University of Maryland
Summary:
Poultry farms that have transitioned from conventional to organic practices and ceased using antibiotics have significantly lower levels of drug-resistant enterococci bacteria. The findings suggest that removing antibiotic use from large-scale US poultry farms can result in immediate and significant reductions in antibiotic resistance for some bacteria.

In this study, poultry houses like this, that transitioned to organic practices and ceased using antibiotics, had significantly lower levels of drug-resistant and multi-drug resistant enterococci bacteria.
Credit: Amy R. Sapkota, University of Maryland

Antibiotic use in conventional animal food production in the United States has created public health concern because it has been shown to contribute to the development of antibiotic-resistant bacteria that can potentially spread to humans. A new study, led by Dr. Amy R. Sapkota of the University of Maryland School of Public Health, provides data demonstrating that poultry farms that have transitioned from conventional to organic practices and ceased using antibiotics have significantly lower levels of drug-resistant enterococci bacteria.

Related Articles


The study, recently published in Environmental Health Perspectives, is the first to demonstrate lower levels of drug-resistant bacteria on newly organic farms in the United States and suggests that removing antibiotic use from large-scale U.S. poultry farms can result in immediate and significant reductions in antibiotic resistance for some bacteria.

"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," explains Sapkota, an Assistant Professor with the Maryland Institute for Applied Environmental Health. "It is very encouraging."

Sapkota and her team, which included R. Michael Hulet (Pennsylvania State University), Guangyu Zhang, Sam Joseph and Erinna Kinney (University of Maryland), and Kellogg J. Schwab (Johns Hopkins Bloomberg School of Public Health), investigated the impact of removing antibiotics from U.S. poultry farms by studying ten conventional and ten newly organic large-scale poultry houses in the mid-Atlantic region. They tested for the presence of enterococci bacteria in poultry litter, feed, and water, and tested its resistance to 17 common antimicrobials.

"We chose to study enterococci because these microorganisms are found in all poultry, including poultry on both organic and conventional farms. The enterococci are also notable opportunistic pathogens in human patients staying in hospitals. In addition, many of the antibiotics given in feed to farm animals are active against Gram-positive bacteria such as the 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," Sapkota explains.

While all farms tested positive for the presence of enterococci in poultry litter, feed, and water as expected, the newly organic farms were characterized by a significantly lower prevalence of antibiotic-resistant enterococci. For example, 67% of Enterococcus faecalis recovered from conventional poultry farms were resistant to erythromycin, while 18% of Enterococcus faecalis from newly organic poultry farms were resistant to this antibiotic. Dramatic changes also were observed in the levels of multi-drug resistant bacteria (organisms resistant to three or more antimicrobial classes) on the newly organic farms. Forty-two percent of Enterococcus faecalis from conventional farms were multi-drug resistant, compared to only 10% from newly organic farms, and 84% of Enterococcus faecium from conventional farms were multi-drug resistant compared to 17% of those from newly organic farms. Multi-drug resistant bacteria are of particular public health concern because they can be resistant to all available antibiotics, and are therefore very difficult to treat if contracted by an animal or human.

"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. Now we need to look forward and see what happens over 5 years, 10 years in time," says Sapkota.

She expects that reductions in drug-resistant bacteria on US farms that "go organic" are likely to be more dramatic over time as reservoirs of resistant bacteria in the farm environment diminish.


Story Source:

The above story is based on materials provided by University of Maryland. Note: Materials may be edited for content and length.


Journal Reference:

  1. Amy Rebecca Sapkota, R. Michael Hulet, Guangyu Zhang, Patrick McDermott, Erinna Kinney, Kellogg Schwab, Sam W. Joseph. Lower Prevalence of Antibiotic-resistant Enterococci On U.S. Conventional Poultry Farms That Transitioned to Organic Practices. Environmental Health Perspectives, 2011; DOI: 10.1289/ehp.1003350

Cite This Page:

University of Maryland. "Poultry farms that go organic have significantly fewer antibiotic-resistant bacteria." ScienceDaily. ScienceDaily, 11 August 2011. <www.sciencedaily.com/releases/2011/08/110810085537.htm>.
University of Maryland. (2011, August 11). Poultry farms that go organic have significantly fewer antibiotic-resistant bacteria. ScienceDaily. Retrieved March 26, 2015 from www.sciencedaily.com/releases/2011/08/110810085537.htm
University of Maryland. "Poultry farms that go organic have significantly fewer antibiotic-resistant bacteria." ScienceDaily. www.sciencedaily.com/releases/2011/08/110810085537.htm (accessed March 26, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, March 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Jockey Motion Tracking Reveals Racing Prowess

Jockey Motion Tracking Reveals Racing Prowess

Reuters - Innovations Video Online (Mar. 26, 2015) Using motion tracking technology, researchers from the Royal Veterinary College (RVC) are trying to establish an optimum horse riding style to train junior jockeys, as well as enhance safety, health and well-being of both racehorses and jockeys. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Botswana Talks to End Illegal Wildlife Trade

Botswana Talks to End Illegal Wildlife Trade

AFP (Mar. 25, 2015) Experts are gathering in Botswana to try to end the illegal wildlife trade that is decimating populations of elephants, rhinos and other threatened species. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Elephants Help Keep 18-Wheeler From Toppling Over

Elephants Help Keep 18-Wheeler From Toppling Over

Newsy (Mar. 25, 2015) The Natchitoches Parish Sheriff&apos;s Office discovered two elephants keeping a tractor-trailer that had gotten stuck in some mud upright on a highway. Video provided by Newsy
Powered by NewsLook.com
Baby 'pet' Orangutan Rescued from Chicken Cage Takes First Steps

Baby 'pet' Orangutan Rescued from Chicken Cage Takes First Steps

Reuters - Light News Video Online (Mar. 25, 2015) Buti, a baby orangutan who was left malnourished in a chicken cage before his rescue, takes his first steps after months of painful physical therapy. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins