h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I'd like to recommend this http://www.h2g2.com/A460324 , my entry on Bacteriophages.

Your comments and suggestions would be appreciated.

Thank you.
Sal

Hi,

A very interesting read!

There are a few typos, but the subs can pick them up.

A few points I would like to make:

Bacteriophages are not the completely safe friends you make them out to be - phage DNA/RNA can be incorporated into the genomes of many things: the target bacteria, and in some cases the host (ie the patient). This can lead to many things - disease, tumour formation, etc. Obviously not always, as our own genetic blueprint is riddled with ancient viral DNA

Using phages in an unprotected environment (ie outside the lab) is also fraught with danger - if you get two phages in one host, they can partake in 'viral sex', mixing and matching their DNA/RNA to prodice new strains, which can theoretically be dangerous - imagine if you had a virulent strain of bacteriophage doing its good work on a nasty chest infection, and it turned out that the chest infection had only caught hold because a viral infection (such as rhinovirus or picornavirus) had enabled it to. There you have a very infectious human virus mingling with a very potent bacteriophage. If the virus was to take on board some of the phages killer characteristics, you have a very nasty situation on your hands. This is just a hypothetical situation, btw, but one that shouldn't be ignored.

Also, it may be worth mentioning that bacteriophages can be genetically engineered to act as a vehicle for introducing genes into bacteria deliberately (much in the same way that plasmids are used), to produce GM bacteria that can produce complex substances such as proteins for medicine.

Hope that is of some use!

- Adam

Thank you, yes that's useful. I was aware that the bacteriophage group that splices its DNA into the host DNA was a little rascal for mixing genetic material and that's one reason it isn't used on patients. Also knew that viruses in general were a bit that way inclined.

Sorry to be a pest, I'm usually a careful proof-reader but I can't see the typos - staring at a screen and white pages for ages'll probably do that for you. You couldn't say what they are, could you?

I'll go forth and edit now. Don't want to lull anyone into a false sense of security.

Sal

I can't find any typos now! Probably just my eyes - I'm very tired you know - thankfully it is Friday!

We're both obviously spending too long with our eyes glued to a screen.

I've just been having a nightmare trying to do some editing. I've put in a new conclusion and done a bit of tweaking but every time I click the [update entry] button, the same old entry is displayed. Humph! Maybe it just takes a long time for the system to show the changes. I don't know.

Anyway, the new conclusion is far more cautious. If you would care to cast your tired eyes over it (when they're able to focus - in your own good time) and give me any comments or suggestions you may have, I would be ever so grateful.

I've got a little bit more tweaking to do. I'm going to mention how phages, unlike antibiotics, are more precise in their ability to target a villain so they don't kill the beneficial bacteria like the ones that help with digestion.

Thank you.
Sal

That's riveting reading. Who'd have thought bacteria could fall victim to disease.

I had a vague idea of what viruses are but I have a much clearer idea now. Also, I just thought of bacteria as the stuff that needs to be wiped off kitchen work tops and loos. I agree with Dr Mungbean that if bacteriophages can be used as tools in genetics, it would be good to say so in the article, if only briefly in the interests of completeness.

Thanks Doc and Shorn. I've made a few alterations and additions. Now I'm doing a bit more research on the use of phages as tools for genetic modification. Any further suggestions will be appreciated.

Sal

Well, now I know a whole lot more than I did about viruses, Sal! It's very readable and fascinating.
I don't know enough to comment on anything else but I spotted one typo I think. Under "An infection on your infection" - 1st para, 5th line; types "of" bacteria?

Two question occurred to me. First, in the way that bacteria become resistant to antibiotics could they become resistant to bacteriophages too? And second, these are naturally occurring aren't they, so they already exist in Dr.Mungbean's unprotected environment. Or does the use of these viruses in medicine entail some way of treating them that doesn't happen naturally? Or have I missed the point entirely? .
Wz.

Thanks Wazungu. I'll get on that typo. Maybe that was what the Doc's tired eyes alighted on first time round but were too knackered to see on further inspection.

In answer to your questions:

1) Yes, bacteria become resistant to phages just as they do to antibiotics. You could pretty well anticipate that because it's how evolution works. The data seem to indicate though, that the mutations bacteria have to undergo to gain resistance to phages can also saddle them with disadvantages. In addition, a mutation may only give protection from one phage and, like us, bacteria suffer from a lot of different diseases - different phages.

2) Yes again. They are naturally occurring and they get up to all sorts of gene-juggling mischief left to their own devices. That's one reason that the lysogenic phages (the ones that splice their DNA into the DNA of their host) aren't used in phage therapy. They can give their host bacterium an advantage - at least to start with, by protecting it from other phages (the sort used in phage therapy for example). Then when they eventually cut loose and kill their host, sometimes they cut out their DNA carelessly so they take some of the bacterial DNA with them. Then the host's DNA gets replicated along with the phage. That way genes are transferred between bacteria which could be helpful to the bacteria and bad news for us.

The problem isn't that they know for sure that under a particular set of circumstances a disastrous (from our point of view) genetic mutation will occur because a phage will do some genetic jiggery-pokery with another virus of bacterium. The point is that not enough research has been carried out to know exactly how safe phage therapy is yet. Viruses and bacteria do a lot of gene swapping and scientists have only started looking closely at the phenomenon relatively recently. There's still a lot to learn.

Hope that made sense.
Sal

It does.

Righty-ho. I've plonked this one in the laps of the Powers in the Towers. They think it is a groovy article, and have accepted it into the edited guide! You will hear from them by email when it is up. Good work!

Here is the official bit to close this thread:

"Thanks for your recommendation. You'll be glad to know that we think this
entry is great, and it has now gone into the Editorial Process for future
inclusion in the Edited Guide. When it does get into the Edited Guide, we
will email to let you know, but please bear in mind it can take a while for
entries to go through the sub-editing system. Thanks for writing for the guide!"

Editorial Note: This thread has been moved out of the Peer Review forum because this entry has now been recommended for the Edited Guide.

Congratulations!

I thank you from the bottom of my little amphibian heart!

Good entry, worth being edited indeed! It almost made me feel I was back in the microbiology lab throwing lawn cultures of E coli onto plates, counting plaques and all that other interesting stuff. I thought I'd mention that if you're interested in making this Guide a better reference place for molecular biology etc, there is some work going on to explain DNA (the molecule, not the author :-)) at http://www.h2g2.com/F29208?thread=32452. On numerous occasions I have actually promised to contribute -- hmmm, sadly I haven't delivered anything yet. *slumps in a corner, sulks* Anyway, enjoyed reading your bit! Best regards, SG V

Excellent entry!!

Thanks Santragenius V and One-eye (I'll keep the funny business to a minimum - while you're watching).

Had a look at the DNA article Santragenius. It looks as though it's going to be very interesting. I guess all the folks who are working on it are a bit strapped for time because it seems to be taking a long while to finish it.

I'll put a link to it in my bacteriophage entry, where I first mention DNA and RNA. Are you suggesting I should get involved in the DNA article? If so, I have to say that I'm no expert on DNA. The people who are collaborating on that piece all seem eminently well qualified to do the job - MAs and PhDs - all shining stars compared to dull little me. My small, humble talent is reading through material that seems complicated and full of jargon, sifting out the meaning in it and rendering it into plain English. If that would be useful to you and your compadres let me know how I can help.

Sal

Hiya

IMHO, "reading through material that seems complicated and full of jargon, sifting out the meaning in it and rendering it into plain English", as you so neatly out it, is no small feat, indeed! I know a couple of people who would or should... give up half of their right upper extremity -- that's what you surely and correctly would rename "their right arm" to the benefit of lot of people -- to be able to do....

As to you participating or not - I just thought you might find it interesting to do so, given the (for a lot of people quite, hmmm, different) topic of your entry.

And yes, we are all so very busy that we simply just don't can find the time to get that entry wrapped up.

Or we're exceedingly lazy. OK, OK - at least I am. My primary excuse (as I do seem to remember having put on that not too updated My Space of mine) is that I do try to have a life.

Maybe I should opt for being a phage in my next life. Doesn't seem too complicated once you get your recombinases sorted, I think...

Anyway, that's it (and this is getting severely off topic - sorry)..

B/R,

SG V

Hi Santragenius V

That's kind of you. You're right - I'd call an arm an arm. Can't see the point of making anything seem more complicated than it actually is. Some things just are complicated but if they're not, why do some people go to all the trouble to make them seem so? I'm on the side of "The Campaign for Plain English".

I can't wait to read the DNA entry when it's finished and I'd certainly have a go at doing the article myself sooner or later if someone else didn't. Thing is though, I'd have to research it pretty well from scratch whereas you and the other people who are currently involved in the project are probably experts (judging from your qualifications). The only way I could help such knowledgeable folk would probably be in a sort of secretarial capacity.

Back on topic. Yes, I thought bacteriophages would make a different and interesting topic for The Guide. Glad you thought so too.

Sal

Good to see Bacteriopages on the front page! Well done

(and my first one's pending -- it's rather cool, isn't it?)

All the best,

SG V

Thanks Santragenius V. It's all good news. My "Prion" article has just been recommended today, as well. I'll nip over and have a look at your pending article this evening and share in your satisfaction!

Sal