Navigation Links
Superbug MRSA identified in US wastewater treatment plants

College Park, Md. A team led by researchers at the University of Maryland School of Public Health has found that the "superbug" methicillin-resistant Staphylococcus aureus (MRSA) is prevalent at several U.S. wastewater treatment plants (WWTPs). MRSA is well known for causing difficult-to-treat and potentially fatal bacterial infections in hospital patients, but since the late 1990s it has also been infecting otherwise healthy people in community settings.

"MRSA infections acquired outside of hospital settings known as community-acquired MRSA or CA-MRSA are on the rise and can be just as severe as hospital-acquired MRSA. However, we still do not fully understand the potential environmental sources of MRSA or how people in the community come in contact with this microorganism," says Amy R. Sapkota, assistant professor in the Maryland Institute for Applied Environmental Health and research study leader. "This was the first study to investigate U.S. wastewater as a potential environmental reservoir of MRSA."

Because infected people can shed MRSA from their noses and skin and through their feces, wastewater treatment plants are a likely reservoir for the bacteria. Swedish researchers have previously identified the presence of MRSA in WWTPs in Sweden, and this new UMD-led study confirms the presence of MRSA in U.S. facilities. The study was published in the November issue of the journal Environmental Health Perspectives.

The research team, including University of Maryland School of Public Health and University of Nebraska Medical Center researchers, collected wastewater samples throughout the treatment process at two Mid-Atlantic and two Midwestern WWTPs. These plants were chosen, in part, because treated effluent discharged from these plants is reused as "reclaimed wastewater" in spray irrigation activities. The researchers were interested in whether MRSA remained in the effluent.

They found that MRSA, as well as a related pathogen, methicillin-susceptible Staphylococcus aureus (MSSA), were present at all four WWTPs, with MRSA in half of all samples and MSSA in 55 percent. MRSA was present in 83 percent of the influent the raw sewage at all plants, but the percentage of MRSA- and MSSA-positive samples decreased as treatment progressed. Only one WWTP had the bacteria in the treated water leaving the plant, and this was at a plant that does not regularly use chlorination, a tertiary step in wastewater treatment.

Ninety-three percent of the MRSA strains that were isolated from the wastewater and 29 percent of MSSA strains were resistant to two or more classes of antibiotics, including several that the U.S. Food and Drug Administration has specifically approved for treating MRSA infections. At two WWTPs, MRSA strains showed resistance to more antibiotics and greater prevalence of a gene associated with virulence at subsequent treatment stages, until tertiary chlorination treatment appeared to eliminate all MRSA. This suggests that while WWTPs effectively reduce MRSA and MSSA from influent to effluent, they may select for increased antibiotic resistance and virulence, particularly at those facilities that do not employ tertiary treatment (via chlorination).

"Our findings raise potential public health concerns for wastewater treatment plant workers and individuals exposed to reclaimed wastewater," says Rachel Rosenberg Goldstein, environmental health doctoral student in the School of Public Health and the study's first author. "Because of increasing use of reclaimed wastewater, further research is needed to evaluate the risk of exposure to antibiotic-resistant bacteria in treated wastewater."


Contact: Kelly Blake
University of Maryland

Related biology news :

1. Hunt for superbugs in Australian animals
2. Distinct developmental patterns identified in children with autism during their first 3 years
3. Australian shipping emissions identified
4. The end of an era? Branding horses does not enable them to be identified
5. Nematodes with pest-fighting potential identified
6. Unusual weather events identified during the Black Saturday bushfires
7. Target for potent first-strike influenza drugs identified
8. Skin cancer identified for the first time in wild fish populations
9. New cause of child blindness identified
10. New therapeutic target for prostate cancer identified
11. Parkinsons disease gene identified with help of Mennonite family: UBC-VCH research
Post Your Comments:
(Date:11/18/2015)... , Nov. 18, 2015  As new scientific ... children, doctors and other healthcare providers face challenges in ... families and patients. In addition, as more children continue ... a patient,s adulthood and old age. John ... The Children,s Hospital of Philadelphia (CHOP) . ...
(Date:11/17/2015)... 2015 Paris from 17 ... Paris from 17 th until 19 ... innovation leader, has invented the first combined scanner in the ... same scanning surface. Until now two different scanners were required: one ... capture both on the same surface. This innovation is ...
(Date:11/17/2015)...  Vigilant Solutions announces today that Mr. Dick ... --> --> Mr. ... partnership at TPG Capital, one of the largest global ... in revenue.  He founded and led TPG,s Operating Group, ... from 1997 to 2013.  In his first role, he ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... Nov. 24, 2015  PDL BioPharma, Inc. (PDL) (NASDAQ: ... the company,s president and chief executive officer, will present at ... week in New York City . The ... December 1, 2015 at 9:30 a.m. EST. ... the website at least 15 minutes prior to the presentation ...
(Date:11/23/2015)... Calif., Nov. 23, 2015   Ceres, Inc . ... today financial results for the fiscal year ended August ... --> --> During ... forage and feed products with a better balance of ... signed distribution agreements with several leading crop input providers ...
(Date:11/23/2015)... PISCATAWAY, New Jersey , November 23, ... Centre (CCDC) announces the launch of the ... and the CSD-System, now complemented by three powerful ... support the discovery of new molecules, CSD-Materials for ... complete set of the CCDC,s applications incorporating CSD-Discovery ...
(Date:11/23/2015)... 2015   BioLife Solutions , Inc. (NASDAQ: ... marketer of proprietary clinical grade cell and tissue ... media and a related cloud hosted ... smart shippers ("BioLife" or the "Company"), today ... ), a biotechnology company focused on the discovery, ...
Breaking Biology Technology: