Bacteriophage

After Phil’s great comment on this post, I thought it would be a good idea to re-post Alan’s original article with the video Phil suggested.

Deskarati’s good friend Alan Mason advises us about Bacteriophage. – As a well-known problem persists, whereby current anti-biotics  are proving ineffective against pathogenic bacteria that have evolved resistance to them, Bacteriophages could provide an altogether different technology for tackling bacteria pathogenic to humans, their livestock and their plants. So what are Bacteriophages? – They are naturally occurring viruses which prey on bacteria alone.

Anti-biotics work by disrupting bacterial metabolism, but also have side-effects so that some people are allergic to them. By contrast, bacteriophages are a magic bullet which only attack the bacterium and they are quite specific to one bacterial species alone. A further problem with anti-biotics is that they can also disrupt the “good” bacteria which are a normal, and indeed essential part of the human gut flora.  Bacteriophages will not do this.

Even more important is the fact that it’s possible to breed new kinds of bacteriophages in a few weeks with relatively low-cost research, compared with producing new anti-biotics with high-cost research taking several years to a decade.  Essentially, by using bacteriophages we can keep up with the evolution of bacterial resistance, whereas with antibiotics we inevitably lag behind.

It appears that the Russians have spent more time, effort and money on ‘phage research than the west has ever done.  Alan suggests that it is the resistance of drug companies to a technology that is relatively cheap and which would ultimately spell the end of an era of prescribing large amounts of expensive anti-biotics, that are holding back the development in the west. See more from Alan Mason here.

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6 Responses to Bacteriophage

  1. Phil Krause says:

    I think this is the T7 phage. It was one of the first things to have its entire genome sequenced back in the early eighties. I like it because it looks like a lunar lander. Incredible that something like this could form naturally. It attacks the bacteria E-coli that thrive in our intestines. Here is a short utube video link showing its short life, http://www.youtube.com/watch?v=UjVcn5Mmz-U&feature=youtube_gdata_player
    At 37degrees it only lives for 17 minutes; it finds a host, injects its genetic material into it where it controls the hosts genetic machinery to reproduce another 100 T7 viruses which erupt from the cell killing it while they have all have 17 minutes to find new hosts.

  2. Naan Glozi says:

    That’s interesting, I watched the video but like many of these sorts of things, they have some things right but very often some things wrong. To start with, E-coli live in the intestines, like you said but in the video they show red blood cells. A normal healthy human should never have blood in his intestines and E-coli shouldn’t and probably couldn’t live (for very long) anywhere in the blood system.
    However, the things they normally get wrong, the relative scale of things, they got pretty much spot on in this clip. The diameter of a red blood cell is about 7 μm long by about 2 μm thick. An E-coli bacteria is about 2 μm long by about 0.5 μm thick, so the length of the E-coli is about the same thickness of the red blood cell, this looked about right. The T7 phage has a head diameter of about 0.05 μm and a tail of about 0.03 μm long which also looked about right. Red blood cells do not contain a nucleus which is unusual for our cells, but as a rule of thumb, a nucleated cell (eukaryote) is normally about 10 times larger than a bacteria (prokaryote) which is about 10 times larger than a virus.

    • Deskarati says:

      These scales are mind blowing Naan. Do you have any thoughts on Alan’s idea of using phages as a replacement to antibiotics once we all become resistant, in the not too distant future?

  3. Naan Glozi says:

    They are already being used. Frederick Twort discovered bacteriophages in 1915. Research into them have continued since although limited because they couldn’t be seen until the invention of the electron microscope in the 1940’s. However, since the invention and widespread use of antibiotics during the Second World War, research has diminished except for in former Soviet countries. The only countries where treatment is currently approved is in Russia and Georgia, although in 2006 the United States Food and Drug Administration approved spraying meat with phages for killing food poisoning bacteria (listeria). Although this initially raised concerns since without mandatory labelling consumers will not be aware that meat and poultry products have been treated with the spray. The negative public perception of viruses may also play a role in the reluctance to embrace phage therapy.
    Bacteria can evolve different receptors either before or during treatment; this can prevent the phages from completely eradicating the bacteria. Just as bacteria can evolve resistance, viruses can evolve to overcome resistance; however, the ability to evolve also raises serious safety questions.
    Bacteriophages are much more specific than antibiotics, so they can hypothetically be chosen to be indirectly harmless not only to the host organism (human, animal, or plant), but also to other beneficial bacteria, such as gut flora, reducing the chances of opportunistic infections. They would have a high therapeutic index, that is, phage therapy would be expected to give rise to few side effects. Because phages replicate in vivo, a smaller effective dose can be used. On the other hand, this specificity is also a disadvantage: a phage will only kill a bacterium if it is a match to the specific strain. Consequently phage mixtures are often applied to improve the chances of success, or samples can be taken and an appropriate phage identified and grown.
    Some evidence shows the ability of phages to travel to a required site—including the brain, where the blood brain barrier can be crossed—and multiply in the presence of an appropriate bacterial host, to combat infections such as meningitis. However the patient’s immune system can, in some cases, mount an immune response to the phage (2 out of 44 patients in a Polish trial.
    Phages can usually be freeze-dried and turned into pills without materially impacting efficiency. Temperature stability up to 55 °C and shelf lives of 14 months have been shown for some types of phages in pill form. Oral administration works better when an antacid is included, as this increases the number of phages surviving passage through the stomach. Application in liquid form is possible, stored preferably in refrigerated vials.
    In addition, due to the specificity of individual phages, for a high chance of success, a mixture of phages is often applied. This means that ‘banks’ containing many different phages must be kept and regularly updated with new phages.

    • Deskarati says:

      Very enlightening Naan. It’s good to know that there is some light at the end of the tunnel if antibiotic resistance keeps increasing. But whether we are moving fast enough in this area is still a question.

  4. Phil Krause says:

    Wow! It seems Alfi was right all along, just a century to late. You should have brought him some of those bacteriophage pills back from Georgia Jim.

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