Featured Research

from universities, journals, and other organizations

'Superbugs' found breeding in sewage plants

Date:
December 16, 2013
Source:
Rice University
Summary:
Tests at wastewater treatment plants in China revealed antibiotic-resistant bacteria were not only escaping purification but also breeding and spreading their dangerous cargo.

Antibiotic-resistant bacteria have been raising alarms for years, particularly in hospital environments where public health officials fear they can be transferred from patient to patient and are very difficult to treat. Bacteria harboring the encoding gene that makes them resistant have been found on every continent except for Antarctica, the researchers wrote.
Credit: ACS Publications

Tests at two wastewater treatment plants in northern China revealed antibiotic-resistant bacteria were not only escaping purification but also breeding and spreading their dangerous cargo.

Joint research by scientists from Rice, Nankai and Tianjin universities found "superbugs" carrying New Delhi Metallo-beta-lactamase (NDM-1), a multidrug-resistant gene first identified in India in 2010, in wastewater disinfected by chlorination. They found significant levels of NDM-1 in the effluent released to the environment and even higher levels in dewatered sludge applied to soils.

The study, led by Rice University environmental engineer Pedro Alvarez, appeared this month in the American Chemical Society journal Environmental Science and Technology Letters.

"It's scary," Alvarez said. "There's no antibiotic that can kill them. We only realized they exist just a little while ago when a Swedish man got infected in India, in New Delhi. Now, people are beginning to realize that more and more tourists trying to go to the upper waters of the Ganges River are getting these infections that cannot be treated.

"We often think about sewage treatment plants as a way to protect us, to get rid of all of these disease-causing constituents in wastewater. But it turns out these microbes are growing. They're eating sewage, so they proliferate. In one wastewater treatment plant, we had four to five of these superbugs coming out for every one that came in."

Antibiotic-resistant bacteria have been raising alarms for years, particularly in hospital environments where public health officials fear they can be transferred from patient to patient and are very difficult to treat. Bacteria harboring the encoding gene that makes them resistant have been found on every continent except for Antarctica, the researchers wrote.

NDM-1 is able to make such common bacteria as E. coli, salmonella and K. pneumonias resistant to even the strongest available antibiotics. The only way to know one is infected is when symptoms associated with these bacteria fail to respond to antibiotics.

In experiments described in the same paper, Alvarez and his team confirmed the microbes treated by wastewater plants that still carried the resistant gene could transfer it via plasmids to otherwise benign bacteria.

A subsequent study by Alvarez and his colleagues published this month in Environmental Science and Technology defined a method to extract and analyze antibiotic-resistant genes in extracellular and intracellular DNA from water and sediment and applied it to sites in the Haihe River basin in China, which drains an area of intensive antibiotic use. The study showed plasmids persist for weeks in river sediment, where they can invade indigenous bacteria.

"It turns out that they transfer these genetic determinants for antibiotic resistance to indigenous bacteria in the environment, so they are not only proliferating within the wastewater treatment plant, they're also propagating and dispersing antibiotic resistance," Alvarez said.

"This calls for us to take a look at these breeding grounds for antibiotic-resistant bacteria and how we might be able to create better barriers than chlorination," he said. "I think we need to take a serious look at photo-disinfection processes, like ultraviolet disinfection. It has been shown to be more effective on resistant organisms. We also need a better understanding of how these microbes flow through the environment."


Story Source:

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


Journal Reference:

  1. Yi Luo, Fengxia Yang, Jacques Mathieu, Daqing Mao, Qing Wang, P. J. J. Alvarez. Proliferation of Multidrug-Resistant New Delhi Metallo-β-lactamase Genes in Municipal Wastewater Treatment Plants in Northern China. Environmental Science & Technology Letters, 2013; 131205142138000 DOI: 10.1021/ez400152e

Cite This Page:

Rice University. "'Superbugs' found breeding in sewage plants." ScienceDaily. ScienceDaily, 16 December 2013. <www.sciencedaily.com/releases/2013/12/131216142807.htm>.
Rice University. (2013, December 16). 'Superbugs' found breeding in sewage plants. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2013/12/131216142807.htm
Rice University. "'Superbugs' found breeding in sewage plants." ScienceDaily. www.sciencedaily.com/releases/2013/12/131216142807.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Working Mother DIY: Pumpkin Pom-Pom

Working Mother DIY: Pumpkin Pom-Pom

Working Mother (Oct. 22, 2014) How to make a pumpkin pom-pom. Video provided by Working Mother
Powered by NewsLook.com
San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Bear Cub Strolls Through Oregon Drug Store

Raw: Bear Cub Strolls Through Oregon Drug Store

AP (Oct. 22, 2014) Shoppers at an Oregon drug store were surprised by a bear cub scurrying down the aisles this past weekend. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Family Pleads for Pet Pig to Stay at Home

Family Pleads for Pet Pig to Stay at Home

AP (Oct. 22, 2014) The Johnson family lost their battle with the Chesterfield County, Virginia Planning Commission to allow Tucker, their pet pig, to stay in their home, but refuse to let the board keep Tucker away. (Oct. 22) 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:

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