Possible Antibiotic for MRSA Superbug

darkmeridian writes "Merck has discovered a possible treatment for methicillin-resistant staphylococcus aureus, or MRSA, a virulent superbug resistant to many current antibiotics. The new compound, platensimycin, was found in a sample of South African soil and works by preventing the bacteria from assembling fatty acids into its cell membrane. This mechanism of action is novel among antibiotics, most of which currently block DNA assembly or protein assembly. Of course, this product still has to undergo human testing, but apparently looks promising."

Comments

Superbug vaccine...

[crazyjeremy]

For some reason when I read this I thought it said there was an Antibiotic for the MPAA Superbug (I know it doesn't quite make sense). Sheesh, what a let down. If there was a RIAA/MPAA vaccine, I bet someone could sell millions.

Oh well... I guess it's good that they may actually get some treatment options for this disease. It sounds horrible. According to http://citypaper.net/articles/2005-03-03/cb2.shtml

It usually first appears in a warm, moist section of the body, like an armpit or the crotch. Initially, it is a small, red bump, similar to a spider bite. Within days, it develops into a boil the size of a grapefruit with the potential to spread fatal poisons into the bloodstream. In other strains, it gradually eats away at a victim's flesh. Methicillin-resistant staphylococcus aureus (MRSA) is a highly contagious skin infection that is resistant to the most commonly used antibiotics.

So if some stranger in the supermarket asks you to look at their rash and wonders if it's contagious... don't hesitate to punch them. Or maybe you guys don't live in quite the redneck neighborhood that I do...

Re:Superbug vaccine...

[Abcd1234]

Antibiotic resistant staph is definitely no joke. Once it gets into a hospital, it can be exceedingly difficult to eradicate, and spreads from patient to doctor to patient very easily. Heck, doctors themselves can transmit it from hospital to hospital if they work in multiple facilities. In my case, I had a close family friend who got in a serious motorcycle accident and, among other things, had to get pins placed in his spine. After the surgery, they discovered he had contracted staph, and it was probably brought in by the doctor who performed his surgery (this particular hospital hadn't had a case in a very long time, prior to this).

As a result, they weren't able to close the wound immediately, and in fact had to debride it a number of times. Eventually, they had to put him on vancomycin (once it was clear he had an antibiotic resistant strain), which is a very powerful antibiotic with a number of side-effects.

Re:Superbug vaccine...

[drgonzo59]

MRSA is already here and is bad enough, but there is already fear of the vancomycin resistant staph. Vancomycin, as it is clear from your story, is a last resort antibiotic, when all others have failed. There is evidence that there could be a super-super-bug that would be resistant to vancomycin as well. The common mechanism of action of these antibiotics is to provent the assembly of the cell wall. It so happens that only prokariotic cells (which staph. aureus is) have this external cell wall structure to prevent them from "exploding" due to high internal osmotic pressure. So this cell wall has been and is a good target for antiobiotics.

It is interesting how most of the antibiotics -- this new one and including the first one -- penicillin, are sythesized and produced by fungi. There is a constant battle for nutrition and space between the bacteria and the fungi -- some kind of an evolutionary yin and yang. One will always try to overtake the other and will develop new mechanisms for resistance or attack.

Re:Superbug vaccine...

[wizardofodd]

Talk about timing... 4 weeks ago I was diagnosed with MRSA. They kept me in the hospital in isolation for the first week. The MRSA was located in my right foot. It was so severe that the had to amputate it to in order to save my life. The worst part of the ordeal was spending 2 weeks without Slashdot. The best part was the spongebath with 3 of the nurses. :-)

Now I'm at home taking a antobiotic called cefazolin every 8 hours until the remainder of the infection clears up. But now I get to spend all day reading Slashdot. I guess somepeople would give their right foot to be able to do that. ;-)

Hey, what do you expect me to do, cry about it? Just keeping my spirits up.

Source...code.

[Anonymous Coward]

"The new compound, platensimycin, was found in a sample of South African soil and works by preventing the bacteria from assembling fatty acids into its cell membrane."

Just one more reason for us to not destroy our environment.

Re:Source...code.

[mojojojoe]

South Africa isn't quite third world. It has a dual economy, which our government is doing its best to merge. Needless to say most of the pharmaceutical companies there have learnt to behave well. Some of them go out of their way to assist indigenous communities, especially if they have assisted in finding useful plants and that sort of thing. Also, finding a soil bacteria that produces any antibiotic is not so simple. You have to take thousands and thousands of soil samples and eventually, if you are lucky, you might get one sample that is kinda useful. As a South African, you can regard this as our gift to you, if you think that it is our gift. We all live in the world, South Africans benefit from antibiotics found in other countries soils, so why shouldn't you benefit from stuff found in our soils. The pharmaceuticals companies did the grunt here, so they deserve the payoff.

"Scientific American" Reports on New Antibiotic

[reporter]

For another perspective on this new antibiotic, read the article by "Scientific American".

Of course, a new antibiotic is never the final word in the war on bacteria. The introduction of this new antibiotic, platensimycin, provides yet another opportunity for bacteria to mutate and to develop defenses against it. Eventually, the bacteria will become resistant to platensimycin.

What is not known is whether we can continuously develop new antibiotics that kill new antibiotic-resistant strains of germs and that will not kill human cells. As each successive generation of new antibiotics bombards the bacteria and as it adapts to the new medicines, will the bacteria become so powerful that it cannot be killed?

When will Washington ban the feeding of antibiotics to cattle? I am referring to the use of antibiotics as a food supplement. It is insane.

Re:"Scientific American" Reports on New Antibiotic

[Cyberax]

There's "bacteriophage therapy" ( http://en.wikipedia.org/wiki/Bacteriophage_therapy ) which really works (it was successfully used BEFORE the invention of antibiotics) and doesn't produce resistant bacteria.

Sadly, there's almost no research on this topic.

Re:"Scientific American" Reports on New Antibiotic

[Decker-Mage]

Actually this has already been covered in medical research done in the late '90's. I was part of the project (statistical model and lab sides) and the team (Dr. Guzek, et. al) discovered that if you use any two of three big guns on MRSA it kills it dead. Apparently those particular sub-strains that are resistant to one antibiotic are not to one of the other two. It didn't matter which of the two you chose, just that you used any two in combination.

One nice side benefit was I got immunized against this sucker although that did carry some risk as well (experimental vaccine and all). Not that I ever expect to need it, but you never know.

Re:"Scientific American" Reports on New Antibiotic

[vidarh]

The problem with bacteriophages is that they are extremely specific - for the most part you need to determine the precise strain of a disease, which requires more expensive tests. You then need to fine a bacteriophage that fits that specific strain of bacteria.

So until we start seeing much more significant resistance to antibiotics they're not likely to be cost effective.

Re:"Scientific American" Reports on New Antibiotic

[Stephen H-B]

Since resistance to these antibiotics is so prevalent, feeding them to cattle really doesn't matter. Resistance to one antibiotic does not trigger resistance to another.

I beg to differ. Many families of antibiotics share the same core mode of action, with only a few side-chains different. E.g. the original Penicillin and modern Methicillin are both beta-lactam antibiotics, which attack bacterial cell walls (more specifically, the enzyme that assembles them). Penicillin resistance is due to the bacteria producing a new enzyme (beta-lactamase) which safely inactivates the antibiotic. Current Methicillin resistance has developed gradually, as each new variant of Penicillin is introduced, the enzyme mutates to accomodate it.

If two antibiotics are similar enough, resistance developed against one can confer resistance against the other. Agricultural use of Avoparcin is widely believed to have led to the development of Vancomycin Resistant Enterrococcus (VRE),

Re:"Scientific American" Reports on New Antibiotic

[Stephen H-B]

To clarify, this is why a new antibiotic 'family' is so sought after. A new mode of action can completely step around existing resistance. PS. I believe Vancomycin (the current drug of last resort for MRSA) attacks bacterial protein synthesis. It also causes renal cytotoxicity (kidney damage) and has a narrow theraputic range (the difference between the minimum effective and maximum safe dose).

Won't last long..

[zcat_NZ]

The first humans to start using this drug will probably take half of the prescribed course and stop as soon as they're feeling better, thus helping to evolve a new generation of superbug resistant to this 'superantibiotic'

Re:Won't last long..

[Idarubicin]

The first humans to start using this drug will probably take half of the prescribed course and stop as soon as they're feeling better...

I'm actually hoping that the first humans to start using this drug will be receiving it from an IV bag and will remain anchored to their hospital beds.

If a patient is carrying a bug that's resistant to all other commonly-used antibiotics, I don't really want them walking about on the street.

Re:Won't last long..

[aswang]

The thing is, most of us do harbor extremely resistant organisms in our gut and on our skin. For one thing, community-acquired MRSA has a prevalence of upwards of 30% in some communities. But most of us are loaded with things like Actinobacter and Stenotrophomonas which usually aren't bad actors until we get pumped full of antibiotics that wipe out the rest of our normal flora that keep them in check, so that these multi-drug resistant organisms are all that are left floating around in our bloodstream, free to frolic and play.

Because hospitals are nothing but incubators for antibiotic resistance, physicians actually do their best to try to get their patient out of there as fast as humanly possible, and sometimes this means sending people home with home nursing to get their 14 or 21 or 28 day course of vancomycin instead of sitting around on the ward letting their bacteria exchange plasmids with the bacteria on the other patients, in the walls, crawling all over the equipment, and (probably in the highest concentrations) in the computer keyboards that the hospital staff use.

But the biggest lesson: don't rely on antibiotics to kill virulent bacteria. The best defense is washing your hands frequently.

Links

[MarkByers]

Whilst your comment seems to be factually correct, more people will read it and take it seriously if you supply a source:

"Vancomycin and teicoplanin are glycopeptide antibiotics used to treat MRSA infections."

http://en.wikipedia.org/wiki/MRSA

http://en.wikipedia.org/wiki/Vancomycin

Plus you get some free karma for doing it. Always works! :)

Nature article: antibiotic may never be used

[tehanu]

An article in the most recent issue of Nature discusses this new antibiotic in more detail - the process by which it was discovered, its nature etc. The article however ends with a discussion that the chances of this antibiotic making it to the market is pretty low. First of all, it has to be tested to make sure it is stable (this apparently is a concern that has already risen in animal tests of the new antibiotic) and non-toxic to humans. However, even if the technical problems are resolved, financial problems - antibiotics are simply not profitable for pharmaceutical companies - may kill it. The reasons for the financial problems apply to antibiotics in general:

- It is likely that this antibiotic if released into common use will "meet the fate of its predecessors" as bacteria rapidly require resistance to it. So the time span when it will under heavy demand will be short.
- Regulatory hurdles. "the US Food and Drug Administration (FDA) does not have clear guidelines for approving new antibiotics" meaning the process is even more long and tedious than for normal drugs.
- Antibiotics are only used for sparingly and only for a week or two.

A quote:

But "the next steps are fraught with danger", warns microbiologist Carl Nathan of Weill Medical College of Cornell University in New York. "The obstacles are truly formidable."

Re:No need.

[MagicDude]

Viagara was an accident. They were testing phosphodiesterase inhibitors as a therapy for keeping heart vessels open. It didn't work so well, but they discovered the unexpected side effect of opening vessels in the penis when the subjects were reluctant to return their unused pills.

Travel Time

[Solokron]

Many flock to Africa to eat soil. Contract Malaria.

MRSA is a big deal...

[Bushwuly]

I used to work in a residential facility for disabled children with severe/profound mental retardation, and those who had the hardest time were the ones that contracted MRSA. Because these kids had such significant physical problems, they were often in and out of hospitals and would contract the virus while admitted there. Besides the scary fact that this bug is prevalent in hospitals of all places, it is so dangerous and contageous to children that those who contract it have to be kept in isolation.

Every day I would walk by the isolation ward and look in, just to let the kids know that someone was concerned for them. These children already had the odds stacked against them, and to top it off with the fact those who attended to them had to avoid all physical contact cut me to the heart. How sad is it to be a kid who can never be hugged, having to live without anyone touching them?

If someone can isolate and develop an antibiotic that can cure MRSA, I'll be one of the first in line to shake their hand.

MRSA treatment already exists

[ParanoidCowboy]

It's called Vancomycin, and it's been around for a while. If the pharmacy doesn't stock that, Teicoplanin will also work. Quite honestly, the MRSA is not exactly a superbug. For the most part, these organisms are caught in the hospital - proper handwashing and isolation should prevent most people from evening catching these bugs. The real "superbug" these days is Vancomycin Insensitive Staph Aureus (VISA) - organisms that require concentrations of vancomycin that come close to causing neprotoxicity (kidneys) and ototoxicity (ears) and who knows what else.

Plenty of Human Volunteers

[bill_mcgonigle]

It seems to me if your flesh is being eaten away by an unstoppable bacteria, you're going to be pretty willing to test out a new antibiotic. Sometimes the FDA clinical trials process just isn't sensible.

Another anti-MRSA agent: Mangosteen

[rjamestaylor]

Doing research on a fruit, called mangosteen, out of southeast Asia I came across this article on PubMed (via NIH.gov) entitled Antibacterial activity of alpha-mangostin against vancomycin resistant Enterococci (VRE) and synergism with antibiotics . A natural fruit tree fights the toughest bacteria mankind faces; amazing.

After learning about this fruit and its many documented benefits, I bought into the company that brought it to the market in the US.

MRSA colonization.

[Anonymous Coward]

Not to put a monkey wrench into things, but a substantial proportion of the people reading this are colonized with Staph aureus, and depending upon what part of the world you hail from and your recent medical history, there's a good chance that it's MRSA. If you know a friendly microbiologist, get them to swab your nose. You'd be surprised.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd= Retrieve&db=pubmed&dopt=Abstract&list_uids=1653404 7&query_hl=6&itool=pubmed_docsum/

MRSA is typically resistant to beta-lactam antibiotics, including penicillins and cephalosporins. Just because it's resistant does not mean that it's going to eat away at your flesh. Methicillin sensitive strains will do that just as happily, particularly if they produce leukocidins (eg: MRSA strain USA300).

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd= Retrieve&db=pubmed&dopt=Abstract&list_uids=1644711 0&query_hl=9&itool=pubmed_docsum/

Calling vancomycin a cure for MRSA is exceedingly short sighted. VRSA/VISA (the I stands for intermediate, not insensitive), is becoming increasingly common in some regions. Topical agents, such as mupirocin or chlorhexidine may help to attenuate nasal and skin carriage (groin, axilla etc), but reports of MuRSA are also beginning to surface. It's an uphill battle.

My advice? (And yes, I hold a PhD in the field). Avoid contributing to the problem. Don't suck down antibiotics every time you get the sniffles, especially if you don't have to. More importantly, if your doctor insists upon it, don't stop taking the antibiotics the moment you feel better: finish the entire course, as prescribed. Data to associate feedlot/livestock antibiotic supplements and the transmission of resistant pathogens into human populations is scant. Worry first about the factors you can control. Your children will thank you for it.

Vaccinations for Virulence

[Baldrson]

The book Plague Time : How Stealth Infections Cause Cancer, Heart Disease, and Other Deadly Ailments by Paul W. Ewald outlines a number of interesting strategies for dealing more effectively with the battle against antibiotic resistance. Basically, if you insist on having a world where international transporters (jets, ships, cars, busses, etc) act like mosquitoes to facilitate human-to-human transmission of disease, you have to resort to some other public health measures so that viruses and bacteria (and parasites) are least capable of winning the evolutionary arms race.

Among these measures is to target virulence rather than the pathogen itself. The reason is that a species of pathogen can have varying virulence and you want the last virulent to win the competition for the ecological niche (human body). Ewald gives an example of a particular protein used by a bacteria to convert human lung tissue to useful food -- a protein that costs the bacteria about 5% of its budget but has huge returns. Vaccinating against this protein can let the more benign variants beat out the virulent variants for the lungs of humans, and give the human immune system the kick it needs to construct antibodies to suppress further infection.

Re:No need.

[dan dan the dna man]

Clearly he was trying to get it past your spam filters.

So?

[RandomPrecision]

This isn't newsworthy to me. I don't get viruses - I use Linux.

*ducks*

So true....

[DrYak]

You don't imagine how close you're to the truth.

The S. Aureus is a bacteria that lives on the skin and is harmless most of the time. I said "most", because the bugs is really nasty in some specific area :
- intensive care : patients aren't in good shape, and the bug tries to enter into them. (Some strains are very good at crawling along needles of perfusion)
- surgery : the few specimens that survived the disinfection may try to jump into the wound. Bones (like after an accident) are an example.of wound that aren't very well protected against infection (among other reasons : lower blood flow compared to other organs and thus harder to bring white blood cells and antibodies).

Because it lives on the skin surface they can realy easily travel from one individual to another, just by plain skin contact (think handshaking or on object that everyone touch). And because they're harmless most of the time, there are no symptoms (the carrier isn't sick) and they can travel unnoticed until they reach one critical patient.

So the only patient that is feeling realy bad is the one at the end of the chain (the one in critical care). Among the chain, there's a lot of people who aren't sick (and don't give a fuck about it) and (mostly healthy) people that may have minor skin wounds (requiring some treatement) but don't follow their treatment as they should (because they feel well).

And that's one reason why bacteria are exposed to sub-lethal doses of antibiotics, some of them surviving better, and evolution (huh... sorry... Intelligent Design) doing it's job and making better superbugs.

Note: other reasons appart from bad usage of antibiotics are :
- Moronic prescrition / Pharmaceutical over-hyping : Doctor hears that superbugs are common. Doctors hears about (=gets brainwashed by marketing departement) new superdrug that kills superbug. Doctor start prescribing superdrug for *EVERY SINGLE CASE*, even when not needed. Superbugs become Hyperbugs. repeat ad nauseam.
That's why method are developped to help determine when and what drug is needed. As a student a worked in such a lab.
- Industrial agriculture : Some huge agricultural corporation do very stupid things which all end up with environnement becoming polluted with antibiotics and resistant bacteria appearing "in the wild" due to exposition to sub-lethal doses.

Get a grip, people

[ajs318]

MRSA is a variant of common-or-garden Staph that is resistant to most antibiotics. It's not, however, resistant to soap and hot water.

The problem is that antibiotics are being badly misused. After about three days on penicillin, with two days to go, you start feeling OK again. Now, at this point, you may be tempted to stop taking the stuff. That is the worst thing you can do. Your immune system has recovered a bit, and is now just about strong enough to fight off the bacteria. However, unless you can be sure that you have killed every last one of the germs, there is still a chance that they might breed. And the ones that survived the onslaught of penicillin are going to pass on the "double-hard bastard" gene to their own offspring. So you need to complete the course, using your own recovered immune system with penicillin as backup, in order to deal with the superbugs.

People failing to finish courses of antibiotics are costing the National Health Service {and by extension the taxpayer} money. In fact, penicillin {or the artificially-manufactured equivalent, Amoxil} isn't used so much anymore because there are resistant strains of so many bacteria. My cruel side thinks it's a shame you can't ROLLBACK a medical treatment and leave people sick if they don't complete the treatment properly .....

On the other side of the coin, if you keep taking penicillin for too long, your immune system will eventually stop trying so hard {and again you'll be breeding penicillin-resistant bugs}. Plus, the stuff isn't any respector of the essential bacteria in your body. Too many antibiotics passing through your system might even kill some of the essential bacteria in your septic tank, causing it to smell and making you unpopular with the neighbours.

Re:Coming Soon

[arivanov]

I would not bet on that.

Most Staph strains with antibiotic immunity gain it from a phague infection. While bacteriophagues are very large and complex there is not that much spare room for carry an extra resistance gene on top of what they drag around at the moment. It will most likely have to lose either the penicillin resistance gene or the tissue necrosis toxin gene to accommodate an extra antibiotic group resistance.

In the first case it can be smacked on the head using conventional penicillin derivatives.

In the second case the normal immunity mechanisms will take care of it. By the way, it is the necrosis toxins produced by MRSA which make it so dangerous, not the antibiotic resistance as such. They kill tissue around the infected zone before it actually gets infected creating the environment in which staph can trhive. In addition to that none of the immune system cells can traverse this dead zone and get to the staph either.

This is all IIRC of course, as it has been very long time since I have done something with mol biol and microbiol.

Re:Coming Soon

[aswang]

Actually, it's more likely that these bacteria have been exchanging plasmids rather than getting indepedently infected by bacteriophages, but it amounts to the same thing.

All forms of Staph aureus carry the toxin you mention, though, so there's really nothing to prevent you from getting MSSA necrotizing fasciitis.

And, yes, you pretty much need an intact immune system to successfully fight off infection. We can pump you full of every antibiotic known to man and cause every single bacteria in your system to explode, but without neutrophils and macrophages to clean up the resultant toxic mess, you're likely to eventually go into septic shock, which frequently means an eventual trip to the morgue.