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."

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.

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 [wikipedia.org]

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

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

Re:A cure you say?

[6th time lucky]

Well actually there is vancomycin resistance out there already... VRE [wikipedia.org] is not normally a problem, but has been shown i am pretty sure to transfer its resistance to MRSA in the lab (ie your VRSA), but it hasnt been seen in the wild (thank $Deity) yet.

and as with most things in nature, if it can, it will... (or someone will do it for it...)

Re:Coming Soon

[Firehed]

Super-duper-bug, you mean.

Re:"Scientific American" Reports on New Antibiotic

[chriso11]

That's my view - I think they should use this only in conjunction with one of the few other effective antibiotics. When you use two, then it is much harder for bacteria to develop an immunity to it.

Vanco can be taken orally

[Anonymous Coward]

...if you're using it to treat diarrhea. Seriously! If you look up the molecule's structure, you'll be astonished at the sheer SIZE of that thing. Works great to wipe out flora in the GI without passing into the bloodstream. This is also an advantage of Vanco as an IV drug, as in those cases you typically do not want to wipe out the patient's GI flora. That could lead to other problems...

Re:A cure you say?

[protobion]

Well, since Platensimycin inhibits FabF, which is 3-oxo-[acyl carrier protein] synthase II, and vancomycin prevents incorporation of N-acetylmuramic acid and N-acetylglucosamine - peptide subunits from being incorporated into the peptidoglycan matrix; their mechanisms are exclusive. Theoretically, Platensimycin will therefore work on both MRSA and VRSA strains. Practically, strain sensitivities vary , but with the current level of information, one would expect the new drug to be just as effective on VRSA strains.

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.

Re:Another anti-MRSA agent: Mangosteen (new link)

[rjamestaylor]

My bad, the MRSA article on PubMed is this one [nih.gov]: Activity of medicinal plant extracts against hospital isolates of methicillin-resistant Staphylococcus aureus [nih.gov]. The one I linked to in the parent post was for a similar problematic bacterial strain, but not specifically MRSA. Sorry for the confusion.

For more information from PubMed on the mangosteen fruit and its benefits, see these articles at PubMed via NIH.gov [nih.gov]. Or, go to my website [goxan.net].

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.

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/ [nih.gov]

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/ [nih.gov]

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.

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 [genomic.ch].
- 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.

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).

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.

Re:Superbug vaccine...

[LWATCDR]

Part of the problem is that they never retire older antibiotics. I think penicillin is still being used in cattle feed or some such silliness.

If the drug companies "benched" and old drug for say 10 or 20 years then there is a very good chance that it would become effective again.
The same evolutionary pressures that allow bacteria to gain resistance so quickly should help them loose it as well.