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:3/23/2017)... ... March 23, 2017 , ... ... families and businesses of the Norwalk and Vermillion areas, celebrates the newest ... (N.O.R.A.) is a nonprofit, community-based substance abuse prevention and peer recovery support ...
(Date:3/23/2017)... ... March 23, 2017 , ... Benefits delivery trailblazer, Hodges-Mace, ... and centralized benefits dashboard solving one of the top frustrations in employee benefits ... the first time, employees can access up-to-date information and account balances for all ...
(Date:3/23/2017)... ... March 23, 2017 , ... Hakim Unique Group ... technology company California Healthcom Group (CHG). , The HUG investment is a ... headquarters in California, CHG is a growing, internationally recognized healthcare management, technology, and ...
(Date:3/23/2017)... Scottsdale, AZ (PRWEB) , ... March 23, 2017 , ... ... helping people around the world to manage stress and anxiety. , “Buzzies change ... Serin, neuropsychologist, inventor and co-founder of Buzzies. , Since its launch date in December ...
(Date:3/23/2017)... , ... March 23, 2017 , ... ... a new solution that enables organizations to easily reprint customer invoices, bills, statements ... Server’ automates all of the steps needed to retrieve and print the documents ...
Breaking Medicine News(10 mins):
(Date:3/23/2017)... 23, 2017   Icertis , the leading ... the cloud, today announced an upgrade to the ... to improve clinical trials contract management. Built on ... the solution speeds up clinical trial contracting while ... (CRO). "The pharmaceutical industry is ...
(Date:3/23/2017)... March 23, 2017 A research report ... is expected to reach USD 7.2 billion by the end ... preparation is a procedure in which a sample is preserved ... most analytical procedures since the methods are often allowing repeated ... of the most shared procedures in the lab. In many ...
(Date:3/23/2017)... , March 23, 2017 Ascendis Pharma A/S ... TransCon technology to address significant unmet medical needs in ... a conference call and webcast on Monday, April 3 ... Society in Orlando, Florida , to ... candidates (TransCon Growth Hormone, TransCon PTH and TransCon CNP). ...
Breaking Medicine Technology: