New antibiotic discovered

[mr friendly guy]

http://www.abc.net.au/news/2015-01-09/s ... rs/6007730

Scientists discover 'game-changing' new antibiotic for first time in 30 years

Scientists have discovered the first new antibiotic in nearly 30 years that can kill serious infections without encountering any detectable resistance, giving hope in the fight against evolving drug-resistant superbugs.

The antibiotic teixobactin has been found to treat many common bacterial infections in mice without resistance, including tuberculosis and septicaemia.

Researchers said the antibiotic could one day be used to treat drug-resistant infections caused by the superbug MRSA, as well as tuberculosis, which normally requires a combination of drugs that can have adverse side effects.

"The discovery of this novel compound challenges long-held scientific beliefs and holds great promise for treating an array of menacing infections," said Professor Kim Lewis from Northeastern University in Boston, Massachusetts.

Teixobactin belongs to a new class of compounds and kills bacteria by causing their cell walls to break down.

It seems to work by binding to multiple targets, which may slow down the development of resistance.

What do you think about this discovery? Have your say.
The problem of infections developing drug resistance has worsened in recent years as multi-drug-resistant bugs have developed and drug companies have cut investment.

The World Health Organisation warned last year that a post-antibiotic era, where even basic healthcare becomes dangerous due to risk of infection during routine operations, could come this century unless something drastic is done.

Dr Lewis is the co-founder of the NovoBiotic Pharmaceuticals, which has patented teixobactin.

Dr Lewis and his NovoBiotic colleagues sought to address the problem by tapping into new potential sources of antibiotics.

They developed a way of growing uncultured bacteria in its natural environment using a miniature device called an iChip that can isolate and help grow single cells.

NovoBiotic has since collected about 50,000 strains of uncultured bacteria and discovered 25 new antibiotics, of which teixobactin is the latest and most interesting, Dr Lewis said.

Scientists not involved in the work welcomed the finding, but cautioned that human trials of teixobactin would be key.

"The discovery of a potential new class of antibiotics is good news," said Richard Seabrook of Britain's Wellcome Trust medical charity.

"Screening previously unculturable soil bacteria is a new twist in the search ... and it is encouraging to see this approach yielding results.

"However, we will not know whether teixobactin will be effective in humans until this research is taken ... to clinical trials."

Dr Lewis hopes to start human testing in around two years.

Lets wait for human trials before I go "science fuck yeah," but damn this looks promising especially with the multiple binding sites which reduces resistance.

[Borgholio]

especially with the multiple binding sites which reduces resistance.

That's the key right there. These days a good antibiotic has to be more than just powerful, it has to actually work more than once before being resisted. If this thing turns out to be as good as it sounds in the article, it could save many MANY lives.

[Simon_Jester]

That said, we should probably NOT use it until we know we're using it on otherwise resistant bacteria... and then we should use the hell out of it, so that the bacteria in question are gone, dead, their fields salted and no stone left standing atop another, as it were.

The biggest thing that's making other antibiotics less and less effective is that they are not now and never were used this way.

[madd0ct0r]

I wonder if it's possible to estimate the number of potential antibiotics?
Complex machines as bacteria are, there's only so many unique ways to interact with them, and we want only those that don't kill human cells which must narrow the field somewhat.

[Ziggy Stardust]

I wonder if it's possible to estimate the number of potential antibiotics?

It's a bit tough to say. Theoretically, in a vacuum, there are thousands.

There are two broad classes of antibiotic: bactericidal. and bacteriostatic agents. The former consists of those antibiotics that target the structural integrity of the cell wall or membrane or those that inhibit specific bacterial enzyme. The latter consists of those antibiotics that target protein synthesis and prevent the bacteria from replicating. That is, bactericidal treatment literally kills bacteria, while bacteriostatic treatment only prevents it from reproducing. All of these operate by essentially targeting a specific protein; either a protein embedded in the bacterial cell wall or an integral part of specific cellular pathways. The problem is that a drug developed to target a specific protein may have different effects on different types of bacteria, which may use that protein differently. For example, aminoglycosides interrupt bacterial cell replication by binding to a specific ribosomal subunit, and are most effective against Gram-negative and aerobic bacteria (e.g. E. coli). Lincosamids, on the other hand, operate the same way, but target a DIFFERENT ribosomal subunit, and is primarily used against anaerobic bacteria (e.g. streptococcal). And, of course, both are fairly simple to develop total resistance to, requiring only methylation of the given RNA sequence.

Complex machines as bacteria are, there's only so many unique ways to interact with them, and we want only those that don't kill human cells which must narrow the field somewhat.

Likely, the solution to really treatment bacteria without causing side effects (i.e. killing human cells in the process) without also engendering chemical resistance will necessitate improved technology. Either in the form of medical nanobots of some sort or artificially constructed viral bodies.

[Bedlam]

Likely, the solution to really treatment bacteria without causing side effects (i.e. killing human cells in the process) without also engendering chemical resistance will necessitate improved technology. Either in the form of medical nanobots of some sort or artificially constructed viral bodies.

No need to do things artificially, there are millions (probably billions) or bacteriophages already around, any given gram of dirts likely to contain something that will kill a given bacteria and evolution means that they keep up with resistance. It's just a question of isolating the correct one. There was some work done in the USSR about it but it's more or less died away since.

[Ziggy Stardust]

No need to do things artificially, there are millions (probably billions) or bacteriophages already around, any given gram of dirts likely to contain something that will kill a given bacteria and evolution means that they keep up with resistance. It's just a question of isolating the correct one. There was some work done in the USSR about it but it's more or less died away since.

Phage therapy is certainly promising. The problem with non-artificial bacteriophages is that they are so highly specific; isolating the correct one for a specific bacterium may not be trivial. In addition, they often need to be administered as cocktails containing a variety of different types of bacteriophage in order to effectively treat a bacterial infection. There is also the question of the method of administration itself: a viral body won't necessarily reach the same parts of the body as a similarly administered antibiotic. That is, the method of administration may need to be different for infections in different parts of the body, possibly to the point of necessitating multiple simultaneous localized administrations. Further, there's the question of actually proving phage therapy is a safe long-term solution: for the same reasons we now no longer introduce plant or animal species into an environment to control the population of other invasive species. Introducing a self-replicating entity with evolutionary capacity into the body may lead to all sorts of nasty things we don't want.

The single biggest problem with phage therapy in general is that, under the right circumstances, it can actively ENGENDER rather than prohibit antibiotic resistance. Bacteriophages can incidentally act as mechanisms of DNA exchange for bacteria, potentially spreading resistance. In fact, cholera outbreaks can often occur as a result of non-toxic strains of the bacteria gaining toxicity as a result of phage-mediated genetic exchange.

This is where genetically engineered bacteriophages come in (and other similar artificial viral bodies). While it doesn't remove all of the concerns about phage therapy, it at least alleviates the concerns over needing prohibitively large banks of phages to prepare for any possible infection. They can essentially be programmed to deal with a specific infection (and we can go even further and personalize them based on patient medical status and history). They can also be designed in such a way as to simultaneously alleviate symptoms or avoid Jarisch-Herxheimer reactions.

[Bedlam]

Further, there's the question of actually proving phage therapy is a safe long-term solution: for the same reasons we now no longer introduce plant or animal species into an environment to control the population of other invasive species. Introducing a self-replicating entity with evolutionary capacity into the body may lead to all sorts of nasty things we don't want.

I can't say I'm up to date with the processes but this doesn't seem to be a problem to me because bacteriophages are already in our bodies and have been interacting with humans as long as there have been humans, with, as far as I'm aware, no harmful effects. There may be a difference in concentration during treatment but I wouldn't think it would create a unique situation we haven't already lived through.

[Lotus_Eater]

This compound is a peptide, and it might be broken down more easily than many other antibacterials. I think that the target may be more important than the particular compound that binds to it in this instance.