Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: Geezer on 24/05/2010 07:42:14
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Are we making any real progress to defend ourselves against MRSA, or are we just buying time in the hope that we will find another "miracle" cure, (as we once thought penicillin was)?
Has there been any real change in the methods employed in medical community, or do the old ways that helped to get us into this situation still prevail? We should be concerned about climate change, but we might want to wonder if MRSA (and other self-inficted biological threats) are a much more immediate threat to Humanity.
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MRSA isn't going to kill us all, it's not a bacterium which has appeared fully formed in hospitals, it still behaves, in infected patients, in much the same way that Staphlococcus aureus did before we had antibiotics to kill it. At worst, antibiotic resistance will take us back to the conditions which prevailed before we had antibiotics.. which are the conditions in many parts of the world still.
It wouldn't be a good thing, it would have a considerable negative effect on life expectancy, because as well as being more likely to die from infected wounds, pneumonia, etc the risk/benefit of many surgical procedures would shift sharply away from intervention towards just living with a dodgy hip/malformed digit etc. But it would be a step back by 100 years or so, not a doomsday "threat to humanity".
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If MRSA really got its act together to the point of leaving us back in the "old days" before we had antibiotics, then we would stop bothering to use them. At that point, the evolutionary pressure would be off and, rather than wasting effort being resistant to drugs that don't et used, MRSA would be overrun by ordinary SA.
Then we can go back to using penicillin again; perhaps we might use it properly the second time.
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Contrary to common belief, MRSA is no longer the sole preserve of hospital acquired infections. Increasingly, patients in the community are presenting with community acquired MRSA infections, including abcesses, chest infections and, more rarely, blood infections (septicaemia).
This situation is made worse through the bacteria having acquired, or increased the prevalence of, a number of virulence factors, including one called PVL - Panton Valentine leucocidin. These strains are more common in the US at the moment, but this is usually an indicator of what's to come worldwide, subsequently.
Chris
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Thanks everyone. As Chris points out, this is no longer confined to medical facilities. My wife has already encountered cases that seem to have developed within the community.
Not to be overly pessimistic, but the outlook does seem rather bleak. While it may not drive humanity to extinction, would I be right in assuming that it could return human mortality rates to levels that have not been seen in the last one hundred years or so?
I hope that is not the case, but if it is a possibility, what's the game plan? Absent some "wonder drug" (which would probably only buy us a little more time anyway) what steps are we taking to defeat this thing. I'm sort of getting the impression that nobody really knows what to do.
For example, if we can no longer rely on antibiotics for a "quick fix", do we have to significantly change our outlook on acceptable hygiene practices, just as we did in the past with sanitation practices?
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Fortunatly, for me, there are some strains that are not resistant to older sulfa drugs. This is the reason I am alive after getting a hospital infection in 2005 when I had a new hip implanted. It is rather a frightening prospect - facing a surgery one MUST have and then being infected in the hospital. I also avoid gymnasiums for workouts because of the huge amount of infection out there.
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If you stop using certain antibiotics long enough, bacteria lose their resistance to it. So as new drugs are developed and replace them, there is a chance that after a number of years they can bring out the oldies but goodies again.
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There are new antibiotics under development for MRSA as we speak. Two candidates already look promising: Linezolid (http://en.wikipedia.org/wiki/Linezolid) and the Quinupristin/Dalfopristin (http://en.wikipedia.org/wiki/Synercid) combination drug are sometimes even used already to treat MRSA.
Of course, it's only a matter of time that resistance will build up for these antibiotics as well, and on the long term, we should really start looking at other treatments besides antibiotics to fight these bacteria. Bacteriophagic viruses come to my mind as possible future antibacterial treatments..
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Keep in mind that these "super bacteria" aren't any more pathogenic than their non-drug resistant brethren. They are just harder to kill than the other bacteria, should an infection occur.
We likely regularly get exposed to Staph Aureus, and only rarely get an infection only when the bacteria manages to get through the skin, or our immune system is compromised in some fashion.
What about taking the specific drug resistance proteins, and making then into antigens for a vaccine, perhaps doing something to enhance their immune reaction.
And, thus make Nature naturally select against those drug resistance genes.
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What about taking the specific drug resistance proteins, and making then into antigens for a vaccine, perhaps doing something to enhance their immune reaction.
I don't know if that'll be useful. Most of these specific drug resistance proteins are found within the bacterium, not on the cell wall (though some do). If you're thinking about vaccines, you could only use the ones that are located on the bacterium's surface so they can be presented to our own killer cells and macrophages.