Phage Therapy's Positive Attributes

Let's discuss now what makes phages ideal for human therapy and food treatment.

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1. Phages are very specific with what they infect.

They only infect bacterial cells, never your cells! They also only have the ability to usually infect one type of bacteria as well. This means that a phage used to kill off harmful gut bacteria, isn't likely to kill off beneficial bacteria. We can also easily make cocktails of different phages to ensure that the harmful bacteria are completely destroyed.

• Current antibiotics do not differentiate between harmful and beneficial bacteria. Phages do.

2. Phages don't harmfully interact with your cells.

Unlike some antibiotics, you won't experience any negative affects directly from exposure to a bacteriophage. For one, they are already ubiquitous to the environment. Studies have also shown that phages do not illicit an immune response, meaning that allergies are not likely. Also, they are able to traverse to nearly every part of the body quickly and easily.

• Current antibiotics can cause allergic reactions and other negative responses Phages likely won't.

3.After doing their job, phages disappear.

They don't linger around in your body. Since they require their specific host bacteria to replicate, once that type of bacteria is gone, they can no longer replicate. Studies show that phages leave the system in a little over 24 hours.

4.Phages are "nearly" living organisms and will evolve to surpass bacterial resistances.

As bacteria grow to be resistant to a phage, that phage will evovle around the resistance. A classical predator-prey relationship. Cocktails of phage will likely be used, so this is not a huge concern.

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So let's imagine some ideal ways that phages can be used in combating bacterial illness.

1. Topical application of a bacteriophage salve onto skin lesions.

Everything from pimples and acne, to diabetic foot ulcers and Staph infections could be treated this way. This is perhaps the best use of phages for therapy.

2. Inhalation of a phage cocktail to fight lung infections.

Pneumonia and tuberculosis could be treated despite increasing antibiotic resistance.

3. Injection of phages into the bloodstream to combat systemic bacterial infections.

4.Ingestion of phages into the GI tract to combat things like cholera, E. coli, etc.

5. Phage treated food supplies to protect us from E. coli laden spinach, or Listeria infected hotdogs.

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Next time, we'll discuss the downside to the uses of phages in therapy.

Phage Therapy

Phage therapy is the use of bacteriophages (usually purely lytic) to treat pathogenic bacterial infections. Phages are viruses that invade only bacterial cells and, in the case of lytic phages, cause the bacterium to burst and die, thus releasing more phages. Phage therapy is a potential alternative to antibiotics, being developed for clinical use in the 21st century by many research groups in Europe and the US. After having been extensively used and developed mainly in former Soviet Union countries for about 90 years, phage therapy is now becoming more available in other countries such as USA for a variety of bacterial infections.Phage therapy has many applications in human medicine as well as dentistry, veterinary science and agriculture.

An important benefit of phage therapy is that bacteriophages are usually more specific than common drugs, so one can be chosen to be harmless to not only the host organism (YOU), but also other beneficial bacteria, such as gut flora, reducing chance for opportunistic infections. They also have no known side effects as opposed to drugs, and do not appear to stress the liver or immune system. Because they replicate inside the pathogen, a single, small dose is usually sufficient.

Phages are currently being used therapeutically to treat bacterial infections that do not respond well to conventional antibiotics. They tend to be more successful where there is a biofilm covered by a polysaccharide layer, that antibiotics typically cannot penetrate.

The origins of phage therapy can be traced to the origins of the discovery of phages themselves. Felix d'Herelle discovered and implemented phages as therapeutic agents back in the 1920s. His story is fantastic and should be known by all microbiologists. Read more about him here Felix d`Herelle and the Origins of Molecular Biology

Intro to Bacteriophages

So, Tim studies bacteriophages...well, what the heck are they anyway. Here's a very brief introduction as to what they are and do. There may be some links around the site that will tell you more.

A bacteriophage (from 'bacteria' and the Greek "phagein", meaning 'to eat') is any one of a number of virus-like agents that infect only bacteria. The term is commonly used in its shortened form, phage.

Typically, bacteriophages consist of an outer protein hull enclosing genetic material. The genetic material can be dsRNA, ssDNA, or dsDNA between 5 and 500 kilo base pairs long with either circular or linear arrangement. Bacteriophages are much smaller than the bacteria they destroy - usually between 20 and 200 nm in size.

Phages are estimated to be the most widely distributed and diverse entities in the biosphere, numbering 10^31 virions. Phages are ubiquitous and can be found in all reservoirs populated by bacterial hosts, such as soil or the intestine of animals. One of the densest natural sources for phages and other viruses is sea water, where up to 10^9 virions per milliliter have been found at the surface, and up to 70% of marine bacteria may be infected by phages. They are also found in drinking water and in some foods, including fermented vegetables and meats e.g. pickles, salami, where they serve the function of controlling any growth of bacteria.

Phages are very specific to bacteria, and thus are more accurate and potent than antibiotics. They have been used for over 60 years as an alternative to antibiotics in the former Soviet Union and Eastern Europe. They also have no known side effects, as opposed to drug therapy. They are now seen as a hope against multi drug resistant strains of many bacteria.