Featured Research

from universities, journals, and other organizations

Soil bacteria may provide clues to curbing antibiotic resistance

Date:
May 21, 2014
Source:
Washington University in St. Louis
Summary:
Bacteria that naturally live in the soil have a vast collection of genes to fight off antibiotics, but they are much less likely to share these genes, a new study has revealed. Drug-resistant bacteria annually sicken 2 million Americans and kill at least 23,000. A driving force behind this growing public health threat is the ability of bacteria to share genes that provide antibiotic resistance.

Researchers led by Gautam Dantas have found evidence that soil bacteria do not share drug-resistance genes as often as infectious bacteria.
Credit: Pablo Tsukayama

Drug-resistant bacteria annually sicken 2 million Americans and kill at least 23,000. A driving force behind this growing public health threat is the ability of bacteria to share genes that provide antibiotic resistance.

Bacteria that naturally live in the soil have a vast collection of genes to fight off antibiotics, but they are much less likely to share these genes, a new study by researchers at Washington University School of Medicine in St. Louis has revealed. The findings suggest that most genes from soil bacteria are not poised to contribute to antibiotic resistance in infectious bacteria.

The researchers hope that what they are learning from soil bacteria will help identify ways to reduce gene sharing among infectious bacteria, slowing the spread of drug-resistant superbugs, said senior author Gautam Dantas, PhD, assistant professor of pathology and immunology.

The results appear May 21 in Nature.

"Soil bacteria have strategies for fighting antibiotics that we're only just starting to learn about," Dantas said. "We need to make sure the genes that make these strategies possible aren't shared with infectious bacteria, because they could make the problem of drug-resistant infections much worse."

Most of the antibiotics used to fight illness today were devised by soil microbes, which employ them as weapons in the competition for resources and survival. Penicillin, the first successful antibiotic, came from the soil fungus Penicillium.

But widespread use of penicillin and other newer antibiotics has prompted bacteria to evolve strategies for blocking, evading or otherwise resisting these drugs. Antibiotic-resistant disease now adds $20 billion to annual health-care costs and leads to 8 million additional hospital treatment days in the United States.

For the new study, the scientists analyzed bacterial DNA in 18 soil samples from agricultural and grassland sites from Minnesota and Michigan.

Using a technique they helped develop, the researchers isolated small fragments of bacterial DNA from the soils and screened those pieces for genes that confer antibiotic resistance.

Other scientists have identified sections of genetic code that make it possible for bacteria to share genes. A gene must be close to these "mobility elements" to be shared. The approximately 3,000 antibiotic resistance genes the researchers identified in soil bacteria typically were not close to such elements.

The researchers also found that the antibiotic-resistance genes in soil are linked tightly to specific bacteria, suggesting little sharing between species. In infectious bacteria, though, more frequent sharing of genes creates antibiotic-resistance portfolios that differ greatly among related bacteria.

"We suspect that one of the primary factors that drives the sharing of antibiotic resistance genes is exposure to new antibiotics," Dantas said. "Because soil bacteria need many thousands of years to develop new antibiotics, the bacteria in that community don't encounter these threats anywhere near as often as disease-causing bacteria, which we regularly treat with different antibiotics."

Dantas and his colleagues continue to study factors that affect the spread of drug resistance in bacterial communities in hospitals, the environment and the human digestive tract.

"We were happy to find that antibiotic resistance genes from soil bacteria generally aren't poised to jump suddenly into pathogens," Dantas said. "But we want to do everything we can -- whether it's changing how we treat infections in medical clinics or altering the way we manage the environments where bacteria grow -- to keep the odds stacked against sharing of these genes."


Story Source:

The above story is based on materials provided by Washington University in St. Louis. The original article was written by Michael C. Purdy. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kevin J. Forsberg, Sanket Patel, Molly K. Gibson, Christian L. Lauber, Rob Knight, Noah Fierer, Gautam Dantas. Bacterial phylogeny structures soil resistomes across habitats. Nature, 2014; DOI: 10.1038/nature13377

Cite This Page:

Washington University in St. Louis. "Soil bacteria may provide clues to curbing antibiotic resistance." ScienceDaily. ScienceDaily, 21 May 2014. <www.sciencedaily.com/releases/2014/05/140521133119.htm>.
Washington University in St. Louis. (2014, May 21). Soil bacteria may provide clues to curbing antibiotic resistance. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2014/05/140521133119.htm
Washington University in St. Louis. "Soil bacteria may provide clues to curbing antibiotic resistance." ScienceDaily. www.sciencedaily.com/releases/2014/05/140521133119.htm (accessed September 1, 2014).

Share This




More Plants & Animals News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
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:
from the past week

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