The fight against MRSA

April 11, 2012

I spotted this article yesterday in the Irish Times and felt compelled to share it. It’s a new step in the fight against MRSA…

New research has found that as the superbug MRSA resists antibiotics, it becomes less virulent. 

CLAIRE O’CONNELL

LIFE IS full of trade-offs, and it seems the hospital-acquired “superbug” MRSA is no exception. A new study led by Irish scientists has discovered that when the bacterium acquires resistance to antibiotics, it becomes less virulent, at least in a lab model.

The finding could help shed light on why patients who have compromised immune systems are particularly vulnerable to healthcare-associated MRSA infections.

MRSA develops when a bacterium called Staphylococcus aureus (SA) acquires resistance to a number of antibiotics and becomes methicillin-resistant Staphylococcus aureus (MRSA).

The new study, just published in the open-access journal PLoS Pathogens, looked at SA and MRSA infections associated with medical devices that are surgically implanted in a laboratory model, explains lead author Dr Jim O’Gara from UCD’s Conway Institute.

“Bacteria are naturally present on the skin, where they often don’t cause any problem. But if they stick onto medical devices that are put into the body they can get access through the skin’s barrier and then they can potentially establish an infection,” he says.

“They will form biofilms, which are communities of bacteria attached to the medical device, and those biofilms are almost indestructible. In that case you have to take the device out and put in a new one, which is not always a trivial thing for the patient.”

O’Gara and a colleague at Beaumont Hospital noticed several years ago that SA and MRSA biofilms looked different.

“Our early research in this area revealed a hugely surprising result – that MRSA and SA use different ways of forming biofilms,” says O’Gara.

Their discovery was that SA bacterial cells use sugars to stick to each other and to surfaces as biofilms, while MRSA instead use proteins to form biofilms.

With funding from the Health Research Board, his group brought the project further and looked at the effects of turning SA into MRSA in the lab. They used a preclinical model that introduced infection by allowing the bacteria to form biofilms on implanted medical devices.

Again, the results far exceeded their expectations: when SA became resistant to the antibiotic methicillin (and so became MRSA), its ability to cause illness was toned down.

“What the data show is that if you take SA and you make it resistant to methicillin, you change the way it forms biofilms, but you also make it less virulent in a preclinical model,” says Dr O’Gara, whose group at UCD worked on the project with colleagues at the University of Bath, Harvard Medical School and the University of Nebraska.

“It’s like the bacteria are making a decision to divert their energy towards becoming resistant to the drugs, and they are not going to expend energy producing as many toxins or enzymes.”

In essence, the findings suggest that hospital-acquired MRSA may have have adapted to the hospital environment by sacrificing virulence for antibiotic resistance, according to O’Gara.

“This trade-off works for the pathogen because patients in hospital, particularly in an intensive care setting, can be very immuno-compromised and the pathogen does not need to be very virulent,” he says. “On the other hand, the bacterium does need to be very antibiotic resistant, due to the necessarily high levels of antibiotic usage in intensive care units.”

O’Gara is now looking into how the discovery could be used to help make MRSA less nasty for patients who get infected. “It may open up new ways to find anti-virulence drugs,” he says.

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This article makes great sense to me as it goes some way to explain why my sinuses are chronically infected with MRSA yet I’m otherwise well. It also explains why I’ve had problems over the years with medical implants which have had to be removed having become contaminated with MRSA.

The question is… how the hell do you get rid of MRSA once and for all?

Source: Irish Times HEALTHplus magazine


One Year On

June 9, 2010

I received the lab report from Nottingham today.

My head is still colonised with Staphyloccus aureus but it’s NOT the resistant form of this bug.

I remain clear of MRSA!

Exactly a year ago to the day, I was admitted for surgery in Nottingham with the surgeon who gave me this news today. It’s been a hell of a year since but at least I’m still here to tell the tale.

And it’s really nice to be able to share some good news for a change.


Knowledge of MRSA

July 12, 2008

Did you know that hand washing is an effective way to prevent MRSA contamination and infection? According to a recent survey, the main source of the public’s information about MRSA, is through the media. The results of the survey have shown that there is a clear need to further educate the public on how to prevent the spread of infection. You can find a report here in The Irish Times online. Ever since my own brush with MRSA, I’ve tried to make it my business to become better informed about infection control and to spread the word.

MRSA is a subject close to the heart of The Biopsy Report. Consistently, the top posts on this blog are the ones which contain information on MRSA. The most frequently used search engine terms all refer to queries about MRSA. Terms such as “boils on butt”, “do you have mrsa forever”, “antibiotic resistance”, “chances of mrsa recurrence”, “superbug news”, “what is difference between mrsa and C Diff” and “mrsa nasal swab”, appear regularly and show that there is a huge hunger out there for more information on MRSA. Two funny search terms which appeared recently were “mrsa bed and breakfast” and “steph and staph infection together.” The mind boggles to think what was going through the minds of those people?

There is no doubt that infection control would benefit from greater public awareness. The media coverage of MRSA is far from an ideal source of information because of a tendency towards a sensationalist approach. We need a well-orchestrated campaign to combat the spread of MRSA and where better to start than online. Spread the word, not the germs.