Navigation Links
MRSA study suggests strategy shift needed to develop effective therapeutics
Date:3/17/2009

USA300the major epidemic strain of methicillin-resistant Staphylococcus aureus (MRSA) causing severe infections in the United States during the past decadeinherits its destructiveness directly from a forefather strain of the bacterium called USA500 rather than randomly acquiring harmful genes from other MRSA strains. This finding comes from a new study led by scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The study authors suggest that a radical shift may be needed in how scientists should design MRSA therapeutics. Instead of the current focus on neutralizing MRSA by targeting products of mobile genetic elementsDNA molecules that bacteria acquire randomly by interacting with other bacteriascientists should switch to looking at the permanent DNA backbone (core genome) of USA300 to understand how increased production of certain proteins such as toxins affects its virulence in humans.

NIAID scientist Michael Otto, Ph.D., directed the study, which involved analyzing DNA sequences of the major epidemic forms of S. aureus. The research team found that the lineage of the bacteria fell into three distinct families: (1) USA300 and its forefather, USA500, which are epidemic in U.S. hospital and community settings; (2) MRSA found primarily in hospitals in the United Kingdom and Europe; and (3) MRSA found in hospitals in South America, Europe and Asia.

The researchers then tested the different lineages in mice, observing that the USA300 and USA500 strains were significantly more destructive than the other strains. Further, when interacting with human immune cells, the USA300 and USA500 strains killed nearly 80 percent of the immune cells, compared with a rate of less than 10 percent for all other strains tested. Finally, when the scientists evaluated what in the bacteria was killing the immune cells, they found that levels of alpha toxin and alpha-type phenol-soluble modulins (PSMs) were significantly higher in USA300 and USA500 compared with the other strains. Earlier NIAID studies determined that alpha toxin and alpha-type PSMs play a crucial role in determining the severity of community-associated MRSA infection.

Another important finding of the study, according to Dr. Otto, is that USA300 and USA500 are nearly identical in virulence, as is their level of virulence gene production. This suggests that the Panton-Valentine leukocidin (PVL) and other mobile genetic elements long believed to play key roles in USA300 virulence have no significant impact, because while USA300 carries the PVL and other mobile genes, USA500 does not.


'/>"/>

Contact: Ken Pekoc
kpekoc@niaid.nih.gov
406-375-9690
NIH/National Institute of Allergy and Infectious Diseases
Source:Eurekalert

Related medicine news :

1. Study tracks increasing use of CT on pregnant women
2. First sister study results reinforce the importance of healthy living
3. Tens of Thousands of Back Pain Patients Overtreated in Six Health Plans, According to HealthCore Study
4. Study Finds that Dying Patients and Families Suffer from Lack of Continuity of Physician Care
5. New Clinical Study Finds Masimo Rainbow SET(R) Pulse CO-Oximetry(TM) Accurate in the Noninvasive Monitoring of Fluid Status During Surgery
6. Firefighters Have Narrower-Than-Normal Arteries, Study Finds
7. Drugs Before Stents for Stable Heart Disease, Study Says
8. New Study Shows Probiotic Strain Effective in Boosting Immune Response
9. Studying the female form
10. Aspirin improves survival in women with stable heart disease, according to WHI study
11. New Study Finds PFOA Levels in Drinking Water Are Safe
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/31/2016)... London, Ontario (PRWEB) , ... May 31, 2016 , ... ... more than 2,000 clients already know – London is home to Ontario’s leading day ... and direction of visionary Fayez Tamba began with a unique concept to combine spa ...
(Date:5/31/2016)... ... , ... In his latest video, renowned AstroNumerologist Jesse Kalsi ... presidential candidate Donald Trump as an example, Kalsi describes the way AstroNumerology conveys ... adding numbers up,” says Kalsi. “It is about looking at each individual number, ...
(Date:5/31/2016)... , ... May 31, 2016 , ... Interest is on ... screening tool and as an orthogonal tool for RNAi hit validation. A key reason ... specific guide RNAs—allows rapid generation of CRISPR RNA (crRNA) collections in arrayed formats. ...
(Date:5/31/2016)... ... ... In a recent interview on The Greenburgh Report radio show hosted by Greenburgh, NY ... AM), leading medical insurance advocate Adria Goldman Gross discussed several eye-opening issues that have ... During the interview with Mr. Feiner that aired on May 7, 2016, Ms. Gross, ...
(Date:5/31/2016)... Chicago, IL (PRWEB) , ... May 31, 2016 ... ... industry-leading multichannel marketing services firm and statement solutions provider, for the ... released in the May 2016 issue of Advertising Age, and SourceLink ranked eighteenth ...
Breaking Medicine News(10 mins):
(Date:5/31/2016)...   Plexus Technology Group, LLC (Plexus ... systems (AIMS), is pleased to announce the addition ... of Technology. In this new capacity, Mr. Marcey ... company,s technological development. He will collaborate with each ... expansion of new products, product features and enhancements.  ...
(Date:5/31/2016)... York , May 31, 2016 ... essential ingredient in food, cosmetics and pharmaceuticals, with global ... revenues worth US$ 1.6 Bn. Demand for ... products, juices, and yogurts will continue its upward momentum ... trend will also boost positive sentiment on aloe vera, ...
(Date:5/31/2016)... Israel , May 31, 2016 ... its proprietary plant-based rhCollagen technology for tissue repair products ... Chief Scientist of Israel,s Ministry ... 12 million development project for 2016. The Chief Scientist,s grant ... year,s authorized grant, which totaled NIS 4.7 million.  ...
Breaking Medicine Technology: