Skip to comments.Bacteria In Staph Infections Can Cause Necrotizing Pneumonia (MRSA)
Posted on 01/28/2007 4:09:37 PM PST by blam
Source: Texas A&M Health Science Center
Date: January 28, 2007
Bacteria In Staph Infections Can Cause Necrotizing Pneumonia
Science Daily Researchers at the Texas A&M Health Science Center Institute of Biosciences and Technology at Houston have discovered a toxin present in the bacteria responsible for the current nationwide outbreak of staph infections also has a role in an aggressive pneumonia that is often fatal within 72 hours.
"The virulence of CA-MRSA (community-associated methicillin-resistant Staphylococcus aureus) strains that produce the PVL (Panton Valentine leukocidin) toxin presents a nightmare scenario," said M. Gabriela Bowden, Ph.D., research assistant professor at HSC-IBT and co-senior author. "If the community-acquired strain establishes itself in the hospital setting, it will be difficult to contain."
The most common cause of staph infections, S. aureus is a bacteria found on the skin or in the nose of about 25-30 percent of people. It also can be the culprit in minor skin infections like pimples and boils, as well as major diseases like meningitis, endocarditis, toxic shock syndrome and pneumonia.
In their study, Dr. Bowden and her colleagues at the HSC-IBT Center for Extracellular Matrix Biology used mice to analyze S. aureus Panton Valentine leukocidin (PVL), a pore-forming toxin secreted by bacterial strains associated with both the current outbreak of CA-MRSA and necrotizing pneumonia.
CA-MRSA causes serious skin and soft tissue infections in healthy persons who have not been recently hospitalized or undergone invasive medical procedures, while necrotizing pneumonia destroys healthy lung tissue and can be fatal within 72 hours. With the PVL toxin, the bacterium also attacks infection-fighting white blood cells (leukocytes).
In the 1940s, the high mortality rate from S. aureus was abated by penicillin, but the bacteria soon developed a resistance. Methicillin provided new treatment options for infections in the late 1950s, but as of the late 1990s, it has become resistant.
In December, the United Kingdom had its first documented report of fatal necrotizing pneumonia cases caused by PVL-positive CA-MRSA. Eight hospitalized patients developed infections from CA-MRSA, and two died. It was previously believed the hospitals were free of these virulent strains of CA-MRSA.
Testing several bacterial strains, the HSC-IBT researchers learned PVL itself has an enhanced ability to disrupt cells in the body, and PVL-positive S. aureus has a greater capacity to attach to and colonize the lung, the latter resulting in necrotizing pneumonia.
"Our research shows in vivo that PVL is sufficient to cause pneumonia," Dr. Bowden said. "PVL-producing S. aureus overexpress other factors that enhance inflammation and bacterial attachment to the lung. These combined effects result in a vicious cycle of tissue destruction and inflammation, explaining the rapid onset and lethal outcome of this type of pneumonia."
Using these findings, the next step is additional studies to identify targets for potential development of therapies to treat S. aureus infections, including the PVL-positive strain.
"The present study underscores the aggressiveness of these strains and the urgent need to develop new strategies to battle these infections," Dr. Bowden said.
Other Science Express study contributors from the Center for Extracellular Matrix Biology were Magnus Höök, Ph.D., director and professor; Eric Brown, Ph.D., assistant professor (now at The University of Texas School of Public Health at Houston); Maria Labanderia-Rey, postdoctoral fellow; Vanessa Vazquez, graduate student; and Elena Barbu, graduate student. Florence Couzon, Sandrine Boisset, Michele Bes, Yvonne Benito, Jerome Etienne and François Vandenesch from the University of Lyon and Hospices Civils de Lyon (France) also contributed.
Grants from the HSC, French Ministry of Research, National Institutes of Health, and Neva and Wesley West and Hamill Foundations supported this research.
The Texas A&M Health Science Center provides the state with health education, outreach and research. Its six components located in communities throughout Texas are Baylor College of Dentistry, the College of Medicine, the Graduate School of Biomedical Sciences, the Institute of Biosciences and Technology, the Irma Lerma Rangel College of Pharmacy, and the School of Rural Public Health.
Note: This story has been adapted from a news release issued by Texas A&M Health Science Center.
Staph Infections are not fun.
"The most common cause of staph infections, S. aureus is a bacteria found on the skin or in the nose of about 25-30 percent of people. It also can be the culprit in minor skin infections like pimples and boils, as well as major diseases like meningitis, endocarditis, toxic shock syndrome and pneumonia."
I had this - staph aureus. It's AWFUL. I had to be on bactrum. It got rid of it. I had cold chills and dizziness.
Guy I work with out at the Festival, over Thanksgiving his girlfriend contracted MRSA and lost their baby.
Then over Christmas, he got it and was in a coma for several days.
This is not to be screwed around with.
That's why I wash with anti-bacteria soap at the gym.
You know it!
I can't figure out where I got it.
Don't visit sick people. I don't go to hospitals. I'm a stay at home mom and lead a rather dull life. Our local food store has alcohol wipes that I ALWAYS use on the shopping cart handle.
My GP is very concerned because he sees it showing up in more and more "healthy" people in the general population. He's a thorough guy and did the culture just as a precaution - he was as surprised as I was.
Too bad hospitals don't know how to clean. Tea Tree Oil kills all staph. There is no need for any staph infections. But hey I bet it's a large part of their income.
Hey girl, thought you might like to read this. It's quite interesting, scary but interesting.
I had to antibiotics and a special liquid soap to rub from neck down to get rid of it.
The staph was on the back of my right thigh.
I have transported patients with MRSA and never got it. I wore gloves and washed my hands after. I cleaned the ambulance with care. I wasn't worried about getting it, and I didn't. Luck of the draw?
This is not true. Tea tree oil can prevent the spread of some bacteria and minor skin infections, even of MRSA. It is not effective in eliminating the threat of MRSA, especially in a hospital setting. I would be the first to agree that hospitals try to gouge patients. I experienced it this weekend. But MRSA scares them. It is impossible to prevent MRSA infections, and there are cases that will only respond to one antibiotic. These infections are bad and scary, and if there was a way to prevent them, the hospitals would be all over it.
By the way, tea tree oil is very, very similar in composition and effect to turpentine.
My mom got a staph infection after her second open-heart surgery.....she was allergic to every single antibiotic available to fight it and was taken off each one as symptoms appeared. When there was nothing left to try they said "we wait and see". She survived that and went over a year without any more problems. She eventually died from CHF.
I guess my point is you can fight it. She was frail from her surgery, yet she overcame a staph infection on her heart.
Sorry I am HTML challenged. Cut and paste works. Tea tree oil is used extensively in Australia and the Islands. MRSA there is practically unheard of there. I have suggested to both local hospitals that they establish MRSA isolation wards and that ALL cases suspected of being MRSA get immedaitely screened and isolated. Their response leads me to beleive that they are more greedy than scareed.
I also have a hunch that if ALL the case history of MRSA was correlated there is some lifestyle or personal hygene issues. No data casue it just isn't there but a theory.
One case from the UK involved a soldier who was infected simply from being scratched by vegetation during training exercises. So it's in the wild, outside of hospitals.
Also, you can be a carrier:
"MRSA can be transmitted from person to person fairly
easily, mainly via the hands. It is important to remember
that MRSA rarely causes problems for fit and healthy
people. Many people carry MRSA without knowing it
and never experience any ill effects. (These people are
said to be colonised with MRSA rather than being
infected with it). In most cases, MRSA only poses a
threat when it has the opportunity to get inside the body
and cause an infection, for example via wounds or surgical
The hospitals in the UK have their own "special" varieties of MRSA, not found elsewhere:
"The MRSA epidemic plaguing Britain's hospitals may be due to extremely transmissible contagious clones of the superbug, a scientist has claimed.
Dr Mark Enright, from the University of Bath, also said that better hospital hygiene would not be enough to prevent the spread of the infection.
In an article published in this month's edition of 'Microbiology Today', Dr Enright, an expert on the evolution and epidemiology of MRSA, said that the increase of infections in the UK coincided with the appearance of two clones, called UK Epidemic MRSA clone-15 and clone-16. These clones, Dr Enright said, were uncommon elsewhere in the world, and this could explain why MRSA infections had increased in Britain.
Dr Enright said that these clones were more contagious than other strains of the infection and claimed that the only way to stop the epidemic was by using proven measures, such as patient isolation."