PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Serendipity contributes to MRSA susceptibility findings

2010-09-04
(Press-News.org) DURHAM, N.C. – Duke University Medical Center researchers have found two genes in mice which might help identify why some people are more susceptible than others to potentially deadly staph infections.

The researchers uncovered important genetic clues that ultimately could help inform patient management and drug development.

"If you know up front that a patient is at risk for developing an Staphylococcus aureus infection, then you will be better able to manage them clinically, give them preventive measures, and treat them more aggressively if they become ill," said Vance Fowler, M.D., MHS, an associate professor of infectious diseases in the Duke Department of Medicine. MRSA is a severe form of the infection, methicillin-resistant Staphylococcus aureus.

Knowing more about the genetics would give a heightened awareness of individual susceptibility for a condition that injures and kills many people each year, and that is no longer just confined to intensive care units and hospitals, he said.

Knowing about genetic susceptibility could also help to uncover the pathways involved in how host and pathogen interact, Fowler said.

The discovery of two highly promising susceptibility genes happened because just the right mice for this inquiry were available.

"We think this study was a real win," Fowler said. "However, it also goes to show that sometimes it's better to be lucky than good."

Scientists had observed that two strains of laboratory mice had different courses of Staphylococcus aureus (SA) infection, one susceptible to severe infections (A/J) and one that was resistant and had much milder infections(C57BL/6J or C57). These two mouse strains had been further modified, so that the more-resistant C57 mice were bred to contain both versions of one chromosome from the susceptible A/J strain. These modified mice were commercially available at Jackson Labs.

"This lucky break allowed us to narrow our search for genes governing susceptibility to S. aureus from 21 chromosomes to just three." Fowler said. "We finally narrowed the search to two genes on chromosome 18 and were able to show that each of these genes appears to influence the immune response to S. aureus."

The team tested one chromosome substitution strain at a time, narrowing the staph susceptibility down to chromosomes 8, 11, and 18. They focused on these three chromosomes because the more-resistant mice that received the "wimpier" mouse chromosome 8, 11, or 18 were found to have the poorest survival times after infection.

Next, they examined the genes on these three chromosomes that were expressed differently when the resistant and susceptible mice were infected with SA.

For chromosome 18, they used Quantitative Trait Loci (QTL) mapping to narrow the search even further by identifying the genetic reassortments present in the offspring of sensitive versus resistant mice. They found 10 candidate genes.

Next, they silenced each of these genes, one at a time, to see which had an impact on the immune cells. Of the 10 genes, the investigators found two that influenced the immune system.

Fowler credits postdoctoral researcher Sun Hee Ahn PhD with doing most of the painstaking work involved in the series of experiments. Detailed examinations of chromosomes 8 and 11 remain to be done.

Fowler said that it's possible the genes they uncovered could play a role in other types of bacterial infections. "We don't know if these results are exclusively for gram-positive bacteria like S. aureus, for example, or if they could also be important in susceptibility to gram-negative bacteria, as well."

"Chromosomal substitution strains let us narrow down the region of interest, dramatically, and they are a readily available tool," he said. "The substituted strains haven't been used much in the infectious disease world yet, but I hope that will change with these results."

Genetic information could ultimately help to identify human populations that are susceptible to SA infections, said Fowler, who is a member of the Duke Clinical Research Institute. "We're testing the importance of these candidate mouse genes in DNA from human patients with S. aureus infections that we have collected over the past 10 years."

### The results were published online in PLoS Pathogens on Sept. 2. The work was supported by a grant from the National Institute of Allergy and Infectious Diseases.

Other authors include Hitesh Deshmukh, Thomas H. Rude, Aimee Zaas, Supaporn Lamlertthon and Batu K. Sharma-Kuinkel of Duke Department of Medicine; Nicole Johnson and Lindsay G. Cowell of the Department of Biostatistics and Bioinformatics; William K. Scott of the Department of Human Genetics and John P. Hussman Institute for Human Genomics, Miller School of Medicine at the University of Miami in Florida; Douglas A. Marchuk and Sehoon Keum of the Duke Department of Department of Molecular Genetics and Microbiology; Charlotte L. Nelson of the Duke Clinical Research Institute; and Gregory D. Sempowski of the Duke Department of Medicine and the Duke Human Vaccine Institute.

END



ELSE PRESS RELEASES FROM THIS DATE:

Pivotal study finds link between PTSD and dementia

2010-09-04
Results of a study reported in the September issue of the Journal of the American Geriatrics Society suggest that Veterans with post-traumatic stress disorder (PTSD) have a greater risk for dementia than Veterans without PTSD, even those who suffered traumatic injuries during combat. Exposure to life threatening events, like war, can cause PTSD, and there are high rates among veterans. PSTD includes symptoms such as avoiding things or people that remind a person of the trauma, nightmares, difficulty with sleep, and mood problems. "We found Veterans with PTSD had ...

Risk of marijuana's 'gateway effect' overblown, new UNH research shows

2010-09-04
DURHAM, N.H. – New research from the University of New Hampshire shows that the "gateway effect" of marijuana – that teenagers who use marijuana are more likely to move on to harder illicit drugs as young adults – is overblown. Whether teenagers who smoked pot will use other illicit drugs as young adults has more to do with life factors such as employment status and stress, according to the new research. In fact, the strongest predictor of whether someone will use other illicit drugs is their race/ethnicity, not whether they ever used marijuana. Conducted by UNH associate ...

Carlos '97 free kick no fluke, say French physicists

2010-09-04
Roberto Carlos' free kick goal against France in 1997's Tournoi de France is thought by many to have been the most skilful free kick goal - from 35m with a powerful curling banana trajectory - ever scored; but by others to have been an incredible fluke. Taken in 1997, a year before the French won the World Cup, Brazilian Carlos's goal held France to a frustrating draw but, now, a group of French physicists – perhaps with a nostalgic eye to a happier time for French football – have computed the trajectory and shown that Carlos' goal was no fluke. The research published ...

Brainy worms: Evolution of the cerebral cortex

Brainy worms: Evolution of the cerebral cortex
2010-09-04
Heidelberg, 3 September 2010 – Our cerebral cortex, or pallium, is a big part of what makes us human: art, literature and science would not exist had this most fascinating part of our brain not emerged in some less intelligent ancestor in prehistoric times. But when did this occur and what were these ancestors? Unexpectedly, scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have now discovered a true counterpart of the cerebral cortex in an invertebrate, a marine worm. Their findings are published today in Cell, and give an idea of what ...

IRCM researchers pave the way for a better understanding of HIV infection and AIDS

2010-09-04
Montreal, September 3, 2010 – Dr. Éric A. Cohen, Director of the Human Retrovirology research unit at the Institut de recherches cliniques de Montréal (IRCM), and his team published yesterday, in the online open-access journal PLos Pathogens, the results of their most recent research on the role of the Vpr protein in HIV (human immunodeficiency virus) infection and AIDS (acquired autoimmune deficiency syndrome). "We previously identified that HIV, when infecting target cells, blocks cell division and induces cell death," says Dr. Cohen. "We then discovered that the Vpr ...

New discovery could pave the way for identification of rogue CFC release

New discovery could pave the way for identification of rogue CFC release
2010-09-04
A new discovery by scientists at the Universities of East Anglia and Frankfurt could make it possible in future to identify the source of banned CFCs that are probably still being released into the atmosphere. Using mass spectrometers, the researchers analysed air samples collected in the stratosphere by balloons belonging to the French space agency, the Centre National d'Etudes Spatiales (CNES). They discovered the largest chlorine isotope enrichment ever found in nature. CFCs were banned in most countries because of their depletion of the ozone layer. Due to their ...

16.6 million small business employees could benefit from ACA provisions starting this year

2010-09-04
New York, NY, September 2, 2010—16.6 million small business employees work in firms that will be eligible for tax credits under the Affordable Care Act (ACA), according to a new Commonwealth Fund report. The credits, designed to offset health insurance premium costs and help small businesses afford and maintain health insurance, are available in taxable years beginning in 2010. Researchers estimate that by 2013, 3.4 million workers may work in firms that take advantage of the tax credit. The tax credits increase in value in 2014, from up to 35 percent of the employer's ...

Hubble observations of supernova reveal composition of 'star guts' pouring out

Hubble observations of supernova reveal composition of star guts pouring out
2010-09-04
Observations made with NASA's newly refurbished Hubble Space Telescope of a nearby supernova are allowing astronomers to measure the velocity and composition of "star guts" being ejected into space following the explosion, according to a new study led by the University of Colorado at Boulder. The team detected significant brightening of the emissions from Supernova 1987A, which were consistent with some theoretical predictions about how supernovae interact with their immediate galactic environment. Discovered in 1987, Supernova 1987A is the closest exploding star to Earth ...

Scientists discover the mechanisms and function of a type of mysterious immune cell

2010-09-04
LA JOLLA, CA – August 31, 2010 –– In two closely related studies, two teams of Scripps Research Institute scientists have discovered the underlying mechanisms that activate a type of immune cell in the skin and other organs. The findings may lead to the development of new therapies to treat inflammation, wounds, asthma, and malignant tumors. The results of the two companion studies were published in the September 3, 2010 issue of the prestigious journal Science. Together, the new research sheds light on γδ (pronounced "gamma delta") T cells, an immune cell found ...

Protecting the lungs against 'collateral damage' from the immune system

2010-09-04
A study published today in the journal Science shows how our bodies try to minimise potential 'collateral damage' caused by our immune system when fighting infection. The research may also provide new clues to why cigarette smoke is a significant risk factor for developing diseases of the lung such as chronic bronchitis and emphysema. When bacteria or viruses enter the body, our immune system fights back to neutralise any danger. One of the key 'soldiers' working for the immune system is a particular type of cell known as a neutrophil, which releases toxic enzymes to ...

LAST 30 PRESS RELEASES:

Public take the lead in discovery of new exploding star

What are they vaping? Study reveals alarming surge in adolescent vaping of THC, CBD, and synthetic cannabinoids

ECMWF - delivering forecasts over 10 times faster and cutting energy usage by 1000

Brazilian neuroscientist reveals how viral infections transform the brain through microscopic detective work

Turning social fragmentation into action through discovering relatedness

Cheese may really be giving you nightmares, scientists find

Study reveals most common medical emergencies in schools

Breathable yet protective: Next-gen medical textiles with micro/nano networks

Frequency-engineered MXene supercapacitors enable efficient pulse charging in TENG–SC hybrid systems

Developed an AI-based classification system for facial pigmented lesions

Achieving 20% efficiency in halogen-free organic solar cells via isomeric additive-mediated sequential processing

New book Terraglossia reclaims language, Country and culture

The most effective diabetes drugs don't reach enough patients yet

Breast cancer risk in younger women may be influenced by hormone therapy

Strategies for staying smoke-free after rehab

Commentary questions the potential benefit of levothyroxine treatment of mild hypothyroidism during pregnancy

Study projects over 14 million preventable deaths by 2030 if USAID defunding continues

New study reveals 33% gap in transplant access for UK’s poorest children

Dysregulated epigenetic memory in early embryos offers new clues to the inheritance of polycystic ovary syndrome (PCOS)

IVF and IUI pregnancy rates remain stable across Europe, despite an increasing uptake of single embryo transfer

It takes a village: Chimpanzee babies do better when their moms have social connections

From lab to market: how renewable polymers could transform medicine

Striking increase in obesity observed among youth between 2011 and 2023

No evidence that medications trigger microscopic colitis in older adults

NYUAD researchers find link between brain growth and mental health disorders

Aging-related inflammation is not universal across human populations, new study finds

University of Oregon to create national children’s mental health center with $11 million federal grant

Rare achievement: UTA undergrad publishes research

Fact or fiction? The ADHD info dilemma

Genetic ancestry linked to risk of severe dengue

[Press-News.org] Serendipity contributes to MRSA susceptibility findings