Fighting Infection with Phages

Fighting Infection with Phages

Modern medicine faces a serious problem. Thanks in part to overuse and misuse of antibiotics,
many bacteria are gaining resistance to our most common cures. Researchers are probing possible alternatives
to antibiotics, including phages. Dr. Shayla Hesse: “So, bacteriophages, or we like to call them
phages for short, are naturally-occurring viruses that infect and kill bacteria. Their basic structure consists of a head,
a sheath, and tail fibers. The tail fibers are what mediate attachment
to the bacterial cell. The DNA stored in the head will then travel
down the sheath, and be injected inside the cell. Once inside the cell, the phage will hijack
the cellular machinery to make many copies of itself. Lastly, the newly-assembled phages burst forth
from the bacterium, which resets their phage life cycle and kills the bacterium in the process. Someday, healthcare providers may be able
to treat MRSA and other stubborn bacterial infections using a mixture of phages, or a
“phage cocktail.” Dr. Randall Kincaid: “The process would be first to identify what the pathogen is that’s causing the infection, so the bacterium is isolated, and characterized,
and then there’s a need to select a phage in a process known as screening of phage,
that are either present in a repository or in a so-called phage library, that allows
for many of the phages to be evaluated for effectiveness against that isolated bacterium.” Phages were first discovered over a hundred
years ago, by a French Canadian named Felix d’Herelle. They initially gained popularity in eastern Europe. However, Western countries largely abandoned
phages in favor of antibiotics, which were better-understood, and easier to produce in
large quantities. Now, with bacteria like these gaining resistance
to antibiotics, phage research is gaining momentum in the United States once again. NIAID recently partnered with other government
agencies to host a phage workshop, where researchers from NIH, FDA, the commercial sector, and
academia gathered to discuss recent progress. NIAID also conducts and supports research
on phages. “The research that I’m working on now is
aimed at answering the question of what makes a good phage for phage therapy. There’s a diversity of phages out there,
and how do we choose, or engineer, the best phages for use for therapeutic purposes.” Through research on phages, and other efforts,
NIAID is committed to outpacing antimicrobial resistance.


  1. May i ask what happens to theoraticly, perfectly designed phages that are injected to destroy Bacteria XY after all Bacteria XY have been "destroyed"/"blown up"? Does the phage virus remain in the body or does it die together with the declining Bacteria XY population in the body ?

    Since antibiotics act like a bomb for bacteria ( from my amateur understanding ) meaning they also destroy good bacteria, would it be plausable to assume that phages that remain in the body will start to nourish on other bacteria that is not wanted ?

    Thanks for the great video!

  2. If you live in bacteria 50 or 60 percent youre screwed they dont use phages at least its rare but you can find them everywhere even in youre body but sometimes there are tooooo much bacterias more then the phages so phages need time and you have to hope that the phages end it before youll die + maybe its a bacteria phage is not targetet to.

    My english is bad sooooo yeah dont blame me for bad wrighting.
    (Im not born in us or uk thats why you dont blame me).

  3. When I was studying microbiology, I was speaking to my professor about this very application. The problem we discussed was that this sort of treatment is usually only valid for the first treatment. You could never use the phage a second time if the patient becomes reinfected because the body would develop an immune response to the phage, as it is a foreign invader. Is this still an issue, and if so, how do you combat it??

  4. I had this idea at some other point, but have no background in medicine. Glad to see it wasn't such a crazy idea after all. The possibilities of using the greatest strength of a virus are truly something worth exploring. Things like fixing genetic defects, adding immunities, and maybe even physical enhancement could be possible with the right minds working on it.

  5. Dear Niaid thanks for the great video! I was wondering if you could grant me permission to use this video or another animation you may have showing the infection cycle.. We are a new startup company and we will attend an exhibition event in September so sth like that could be great to communicate what are phages actually able to do. Thanks in advance.

  6. I am a little late, but if anyone can answer this I would appreciate it. Could phages be responsible for curing or causing the remission of diseases in situations where alternative or homeopathic cures are thought to be responsible? From what I understand, the phages used to cure various diseases are found in nature, identified, and selectively reproduced in a lab setting in order to make enough of that particular phage for theraputic purposes. Does this mean if somebody with a particular disease comes across the a phage that kills that bacteria in the wild it would have no observable effect? At what threshold does a phage stand a chance of killing the bacteria? From everything I have been able to find, it seems like even a few phages could use a host bacteria to reproduce on a massive scale because they take over the bacteria and force it to produce more phages until the bacteria bursts.

  7. Phage therapy was popular long ago and was never stopped in Georgia Russia and should of been continued here as soon as anti-biotic resistant bacteria First showed up! No need to waste money on research just use it!

  8. Thank you for this great video but my question is could phages treat intracellular infections like mycobacteria given that phages can't go inside human cells which don't have receptors for these viruses

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