4 ms·

The article mentions phage therapy in passing, and links to this Nature article: http://www.nature.com/news/phage-therapy-gets-revitalized-1.15348 http://www.n

The article mentions phage therapy in passing, and links to this Nature article: http://www.nature.com/news/phage-therapy-gets-revitalized-1.15348 http://www.nature.com/news/phage-therapy-gets-revitalized-1.... The Nature article hints that the main barrier to adoption is that it's difficult to for pharmaceutical companies to make a profit out of phage therapy: the cure is entirely natural, bacteriophage are the most common organisms on the planet, they reproduce very quickly, and evolve to overcome bacterial resistance.

DiffEq 10y ago
You used the word "evolve" - I don't think this means what you think it means. Evolving means that positive mutations are occurring that assist these organisms; what is really happening is Natural Selection; where already present genetic capabilities are being favored and those populations are thus surviving.
- barrkel 10y ago
  Mutation + selection = evolution. Evolution doesn't necessarily mean positive mutations that assist. See http://evolution.berkeley.edu/evolibrary/misconceptions_faq.php#a3 http://evolution.berkeley.edu/evolibrary/misconceptions_faq....
- DonaldFisk 10y ago
  Mutations occur in bacteriophage. Those mutant bacteriophage which can attack previously resistant bacteria are then selected for and become more prevalent.
  - DiffEq 10y ago
    Your assertion has never been observed with any certainty that could withstand normal scientific inquiry; not even this experiment gives such certainty: https://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment https://en.wikipedia.org/wiki/E._coli_long-term_evolution_ex...
    - barrkel 10y ago
      The parent is talking about a virus; the wikipedia article talks about a bacterium. Can you explain further what it is refuting and how?
      - DiffEq 10y ago
        The article focus, and my focus, is a about how or if there is actual evolution occurring within DNA. It is separate and apart from the organism in question. My point is that almost everybody these days mixes up evolution and natural selection when they are two very distinct things.
        aidenn0 10y ago
        All forms of selection that differ from the current equilibrium cause evolution in a group that is either sufficiently diverse group (assuming HGT or sexual reproduction) or has a sufficiently high mutation rate.
slv77 10y ago
Each bacteriophage typically targets just one or at most few types of bacteria. The targeted treatment in many ways is an advantage because a phage treatment to target a pathogen wouldn't also wipe out the symbiotic bacteria that we are increasing finding act as part of our natural defense mechanism against pathogens. The challenge for drug companies is that they would need to isolate and get regulatory approval for each pathogenic bacteria that they wanted to treat. Today one of the challenges that drug companies face with developing new antibiotics is that the profit models for antibiotics are poor compared to drugs that treat chronic conditions. With an antibiotic you sell one course of treatment per patient but with a diabetes drug , for example, you're selling a lifetime supply. With a phage your taking the already small pool of money for antibiotic treatment and dividing it by a hundred or a thousand. The other challenge is that using phages as part of a treatment protocol the diagnosing physician would need to culture and identify the pathogenic bacteria and then order a specific phage for treatment which would increase the cost of diagnosis. One possibility would be creating cocktails of phages that would target many different strains of phages but that would require complex revenue sharing agreements unless all the phages were developed by one drug company. And while phages work great in vitro the don't always work as well in vivo because they are ... viruses ... which the immune system will attempt to identify and destroy them. Phage therapy for a sore throat, for example, requires gargling a phages in liquid. Not as simple as popping a pill to treat a blood infection.
- DonaldFisk 10y ago
  Other than the last paragraph, the problems you mention are a market failure, which can be dealt with by having all aspects of phage therapy carried out within a government-owned health service, rather than by privately owned pharmaceutical companies. It's worth noting that phage therapy was successfully used in the Soviet Union, and is still used in Georgia where the phage was "farmed", and that attempts to commercialize it have (as far as I know) invariably failed. The clinical problems in administration of phage therapy to patients you mention are well-known and limit their use somewhat. But phage therapy could still be a valuable addition in the fight against pathogenic bacteria, rather than a replacement for antibiotics, which are more convenient, and work very well most of the time.
gambiting 10y ago
I think the problem with making profit out of it is that it's very time consuming(read - expensive) process, which has to be tailored to every person individually. In theory, a phage therapy could save someone who doesn't react to any other antibiotics, but the therapy would need to be prepared specifically for that one person. At least that's what I read about this.
- DonaldFisk 10y ago
  Phages are easier to manufacture, and more expensive to deliver, than antibiotics. They target very specific bacteria. Instead of identifying the bacterial strain (which if I'm not mistaken is done using phages), a cocktail of phages would be administered. Even if that doesn't work, finding a strain of bacteriophage from the environment which does kill the bacteria would still be quicker than developing a new antibiotic.
Fomite 10y ago
That's not the only problem. Every time phage therapy comes up, I end up posting my thoughts on it (and this is from someone who loves, and wanted to work in, phage therapeutics): Phage therapy is neat, it really is, but there are a couple major issues: - There is no such thing as a "broad spectrum" phage. You can't do empirical treatment using phages, and there's not really "off the shelf" phage therapy - it tends to be a bespoke creation for a particular infection. - There's some serious regulatory problems, similar to those experienced by fecal transplant treatments. We're not yet really equipped to think about handling evolving, custom microbes as a treatment. - Because of the first, it's going to require a considerable amount more lab capacity than most clinical settings currently have, and considerable delays until treatment. - There's also some biosafety issues around phage prep, but those are easily solvable. It's a great way to treat particularly resistant or hard to treat infections, but it's not a particularly great general solution. There's a reason it was abandoned in countries with easy access to antibiotics - they're just roundly superior in basically every respect.

DiffEq 10y ago

You used the word "evolve" - I don't think this means what you think it means. Evolving means that positive mutations are occurring that assist these organisms; what is really happening is Natural Selection; where already present genetic capabilities are being favored and those populations are thus surviving.

barrkel 10y ago
Mutation + selection = evolution. Evolution doesn't necessarily mean positive mutations that assist. See http://evolution.berkeley.edu/evolibrary/misconceptions_faq.php#a3 http://evolution.berkeley.edu/evolibrary/misconceptions_faq....
DonaldFisk 10y ago
Mutations occur in bacteriophage. Those mutant bacteriophage which can attack previously resistant bacteria are then selected for and become more prevalent.
- DiffEq 10y ago
  Your assertion has never been observed with any certainty that could withstand normal scientific inquiry; not even this experiment gives such certainty: https://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment https://en.wikipedia.org/wiki/E._coli_long-term_evolution_ex...
  - barrkel 10y ago
    The parent is talking about a virus; the wikipedia article talks about a bacterium. Can you explain further what it is refuting and how?
    - DiffEq 10y ago
      The article focus, and my focus, is a about how or if there is actual evolution occurring within DNA. It is separate and apart from the organism in question. My point is that almost everybody these days mixes up evolution and natural selection when they are two very distinct things.
      - aidenn0 10y ago
        All forms of selection that differ from the current equilibrium cause evolution in a group that is either sufficiently diverse group (assuming HGT or sexual reproduction) or has a sufficiently high mutation rate.

slv77 10y ago

Each bacteriophage typically targets just one or at most few types of bacteria. The targeted treatment in many ways is an advantage because a phage treatment to target a pathogen wouldn't also wipe out the symbiotic bacteria that we are increasing finding act as part of our natural defense mechanism against pathogens. The challenge for drug companies is that they would need to isolate and get regulatory approval for each pathogenic bacteria that they wanted to treat. Today one of the challenges that drug companies face with developing new antibiotics is that the profit models for antibiotics are poor compared to drugs that treat chronic conditions. With an antibiotic you sell one course of treatment per patient but with a diabetes drug , for example, you're selling a lifetime supply. With a phage your taking the already small pool of money for antibiotic treatment and dividing it by a hundred or a thousand. The other challenge is that using phages as part of a treatment protocol the diagnosing physician would need to culture and identify the pathogenic bacteria and then order a specific phage for treatment which would increase the cost of diagnosis. One possibility would be creating cocktails of phages that would target many different strains of phages but that would require complex revenue sharing agreements unless all the phages were developed by one drug company. And while phages work great in vitro the don't always work as well in vivo because they are ... viruses ... which the immune system will attempt to identify and destroy them. Phage therapy for a sore throat, for example, requires gargling a phages in liquid. Not as simple as popping a pill to treat a blood infection.

DonaldFisk 10y ago
Other than the last paragraph, the problems you mention are a market failure, which can be dealt with by having all aspects of phage therapy carried out within a government-owned health service, rather than by privately owned pharmaceutical companies. It's worth noting that phage therapy was successfully used in the Soviet Union, and is still used in Georgia where the phage was "farmed", and that attempts to commercialize it have (as far as I know) invariably failed. The clinical problems in administration of phage therapy to patients you mention are well-known and limit their use somewhat. But phage therapy could still be a valuable addition in the fight against pathogenic bacteria, rather than a replacement for antibiotics, which are more convenient, and work very well most of the time.

gambiting 10y ago

I think the problem with making profit out of it is that it's very time consuming(read - expensive) process, which has to be tailored to every person individually. In theory, a phage therapy could save someone who doesn't react to any other antibiotics, but the therapy would need to be prepared specifically for that one person. At least that's what I read about this.

DonaldFisk 10y ago
Phages are easier to manufacture, and more expensive to deliver, than antibiotics. They target very specific bacteria. Instead of identifying the bacterial strain (which if I'm not mistaken is done using phages), a cocktail of phages would be administered. Even if that doesn't work, finding a strain of bacteriophage from the environment which does kill the bacteria would still be quicker than developing a new antibiotic.

Fomite 10y ago

That's not the only problem. Every time phage therapy comes up, I end up posting my thoughts on it (and this is from someone who loves, and wanted to work in, phage therapeutics): Phage therapy is neat, it really is, but there are a couple major issues: - There is no such thing as a "broad spectrum" phage. You can't do empirical treatment using phages, and there's not really "off the shelf" phage therapy - it tends to be a bespoke creation for a particular infection. - There's some serious regulatory problems, similar to those experienced by fecal transplant treatments. We're not yet really equipped to think about handling evolving, custom microbes as a treatment. - Because of the first, it's going to require a considerable amount more lab capacity than most clinical settings currently have, and considerable delays until treatment. - There's also some biosafety issues around phage prep, but those are easily solvable. It's a great way to treat particularly resistant or hard to treat infections, but it's not a particularly great general solution. There's a reason it was abandoned in countries with easy access to antibiotics - they're just roundly superior in basically every respect.