Bacteria In Staph Infections Can Cause Necrotizing Pneumonia (MRSA)

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.

This is not posted to anyone specific. I just wanted to share my story of Staph infection. i first got in in 2005 after surgery. My PCP could not tell me what it was. Just said it was a skin infection and referred me to a dermotologist, who prescribed another medication after my pcc prescriped something and the the dermotolgist prescriped Cipro. Neither of them helped. They eventually went away after I kept myself clean. And now here I am again with it again. this time I did my own research and took my findings to my PCP who all but looked at me like PLEASE WILL YOU LET ME DO MY JOB?! I was highly offended that he gave me the same exact medication CIPRO that did not work the first time. I however listen to the Dr. and took ever pill prescribed with no luck. Finally I took it upon myself to see a Infectious disease specialist who immediatly knew what it was and prescriped BACTRUM and an ointment that I took and saw results within 24 hours.

The scary thing is that Dr. are soooo unaware that the normal medication for Staph infection does not work.

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.

ROFLOL!!!

Most MRSA cases are hospital acquired..And infect the chronically ill, aged, or immuno-suppressed pt.

Forget your "theory".

AHH you forget that MANY are prison and low income related. Also, it is one of the MOST missed (as in not caught) until well advanced diseases in the world. In addition, there are many parts of the world that it is virtually unheard of - and yes they have hospitals. You can go ahead and laugh but that is the refuge of the uniformed.

"I'm partial to alternative - any recommendations on herbal soaps?"

We make our own soap. Beats any commercial soap. My wife saves fat, grease from cooking, we might mix in a little coconut oil, uses lye (sodium hydroxide) and makes great soap. We bathe with it, grind it up for the laundry. This requires soft water. We do not buy soap of any kind anymore. We do occasionally buy Borax to add to the soap for the laundry.

We don't buy toothpaste either. We keep our toothbrushes soaking in hydrogen peroxide, dip the toothbrush in baking soda, and brush away. My preference is about a 10% solution of peroxide for soaking the toothbrush (We buy 50% hydrogen peroxide by the gallon and dilute it for various household uses).

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