Navigation Links
MRSA in livestock acquired drug resistance on the farm, now infects humans
Date:2/21/2012

Researchers have discovered that a strain of methicillin-resistant Staphylococcus aureus (MRSA) bacteria that humans contract from livestock was originally a human strain, but it developed resistance to antibiotics once it was picked up by farm animals. The findings, which appear in the online journal mBio on Tuesday, February 21, illustrate a very close link between antibiotic use on the farm and potentially lethal human infections.

MRSA is the well-known cause of a variety of invasive skin infections that can quickly turn life-threatening, but in 2003 a novel form of MRSA called ST398 emerged in livestock. Today, ST398 regularly infects farm workers and others who come into contact with infected livestock with any of several types of acute infections, including skin and soft tissue infections, respiratory infections, and bacteremia (also called sepsis). The strain can now be found in pigs, turkeys, cattle, and other livestock and has been detected in 47% of meat samples in the U.S.

It has been thought that overuse of antibiotics in livestock production could be fueling antibiotic resistance in bacteria, including S. aureus. In 2001, the Union of Concerned Scientists estimated that livestock producers in the U.S. used 24.6 million pounds of antibiotics per year for non-therapeutic purposes, a controversial practice that has now been banned in the European Union.

The study appearing in mBio draws a line between the exposure of S. aureus to antibiotics on farms and the development of a form of MRSA that can threaten human lives, a correlation that has long been suspected but has been difficult to study directly.

A team of researchers from the Translational Genomics Research Institute (TGen) in Flagstaff, Arizona, the Statens Serum Institut in Denmark, and several other institutions sequenced the genomes of 88 different S. aureus isolates that are all closely related to ST398 to determine the family relationships among antibiotic sensitive strains and antibiotic-resistant strains from both humans and animals.

An analysis of the various genomes revealed that ST398 most likely evolved from an antibiotic-sensitive strain of S. aureus that came from humans. Once it found a home in livestock, the genome sequences indicate this strain changed rapidly, acquired some new genes, and differentiated into many different types, including ST398, which is resistant to a few different antibiotics.

"Most of the ancestral human strains were sensitive to antibiotics, whereas the livestock strains had acquired resistance on several independent occasions," says Ross Fitzgerald of the University of Edinburgh in Scotland, who reviewed the paper for mBio. This implies that the bacterium picked up the ability to fend off antibiotics after it migrated into livestock, says Fitzgerald.

The fact that ST398 originally came from a human is significant, says Fitzgerald, because it shows that infection is a two-way street. "Intensive farming practices could promote the transfer of bacteria between different host species including humans to animals," says Fitzgerald. ST398's family tree shows that sharing bacteria with livestock could well mean that those bacteria come back to us with the ability to defeat antibiotics.


'/>"/>

Contact: Garth Hogan
ghogan@asmusa.org
202-942-9389
American Society for Microbiology
Source:Eurekalert

Related biology news :

1. Texas researchers provide emissions data for livestock industry
2. Improving livestock productivity in Honduras
3. Major report reveals the environmental and social impact of the livestock revolution
4. Tracking phosphorus runoff from livestock manure
5. Scientists counter brucellosis threat to livestock and wildlife
6. Iowa State, USDA researchers discover eye test for neurological diseases in livestock
7. Evidence of a natural origin for banned drug that plumps up livestock
8. A*Star scientists discover how to combat hospital-acquired infections and life-threatening toxins
9. Study: Residential washers may not kill hospital-acquired bacteria
10. Breast cancer treatment resistance linked to signaling pathway
11. New estrogen receptor found to be key player in tamoxifen resistance
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/19/2017)... April 19, 2017 The global ... landscape is marked by the presence of several large ... held by five major players - 3M Cogent, NEC ... accounted for nearly 61% of the global military biometric ... in the global military biometrics market boast global presence, ...
(Date:4/17/2017)... NXT-ID, Inc. (NASDAQ: NXTD ) ("NXT-ID" or the "Company"), ... Report on Form 10-K on Thursday April 13, 2017 with the ... The ... section of the Company,s website at http://www.nxt-id.com  under "SEC Filings," ... 2016 Year Highlights: Acquisition of ...
(Date:4/13/2017)... -- According to a new market research report "Consumer IAM ... and Authorization), Service, Authentication Type, Deployment Mode, Vertical, and Region - Global ... grow from USD 14.30 Billion in 2017 to USD 31.75 Billion by ... ... MarketsandMarkets Logo ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... DuPont Pioneer and recently ... have entered into a multiyear collaboration to identify and characterize novel CRISPR-Cas nucleases. ... for gene editing across all applications. , Under the terms of the agreement, ...
(Date:10/12/2017)... ... ... AMRI, a global contract research, development and manufacturing organization ... quality of life, will now be offering its impurity solutions as a stand-alone ... for all new drug products, including the finalization of ICH M7 earlier this ...
(Date:10/11/2017)... ... October 11, 2017 , ... ... its endogenous context, enabling overexpression experiments and avoiding the use of exogenous expression ... guides is transformative for performing systematic gain-of-function studies. , This complement to ...
(Date:10/11/2017)... ... October 11, 2017 , ... Proscia Inc ., ... a Webinar titled, “Pathology is going digital. Is your lab ready?” with Dr. ... best practices and how Proscia improves lab economics and realizes an increase in ...
Breaking Biology Technology: