How to combat antibiotic-resistant bacteria

[mistermack]

A quite different phenomena. In the context of, say, golden staph bacteria, it would mean releasing a genetically-engineered strain that, when it shares plasmids, delivers a gene which stops the recipient reproducing.

No it's not the same. It's sort of in the same ball park. But I would have my doubts if GM could really be used on bacteria to engineer a less virulent, or less resistant strain. You would think that those properties were the product of subtle combinations of genes, rather than individual ones.

I've got my doubts about that mosquito project anyway. How do you go about producing billions of mosquitoes with that particular genetic modification? I suppose there is an answer, or they wouldn't be trying it.
If you just released a few, and hoped that the genes would successfully spread, you might find that one in a million female mosquitoes found something unpleasant about these modified males, and wouldn't mate with them. If that trait was inheritable, that would be enough to re-establish a new population, that wouldn't mate with your new males.
Then you're back to square-one.

Out of the two ideas, I think mine would have a better prospect of success, because it's a smaller environment you are working with, and I can't see a mechanism for resistance to the strategy evolving.

I can't see why it wouldn't be very easy to breed strains that are very susceptible to the old antibiotics. You just expose monocultures bred from one individual to a weak concentration of the antibiotics, keeping a few back. The ones that were most affected, you breed from, and start again.

Eventually, you end up finding the most sensitive strains available in the environment, and start again.
More to it than that, of course, but there's no reason it wouldn't be easy.
Selecting for less virulence might take longer and be more involved, but I'm pretty sure the technology will be out there.

In any case, it's not essential to the process. Preferable, but not essential.

[Blind groper]

What would happen if you developed a GM bacterium containing plasmids that both increased fitness (like permitting an extra food to be used), and at the same time destroyed resistance to specific antibiotics. Would not those plasmids be spread around trough the population, and the susceptibility to antibiotics be an evolutionary disadvantage only to those which become pathogenic?

[mistermack]

What would happen if you developed a GM bacterium containing plasmids that both increased fitness (like permitting an extra food to be used), and at the same time destroyed resistance to specific antibiotics. Would not those plasmids be spread around trough the population, and the susceptibility to antibiotics be an evolutionary disadvantage only to those which become pathogenic?

I think it's asking a lot. To artificially improve on the fitness which has built up over billions of years, and do it with a modification that weakens resistance to antibiotic would be some sort of achievement.
Not that I'm in a position to pronounce on it.

[Blind groper]

Mistermack

It has, in fact, been done. Transfer a gene from one bacterium that is able to make use of a particular food, to another, and it makes the second bacterium more fit. It is the combination with a gene for antibiotic vulnerability that I wonder about.

[JimC]

Mistermack

It has, in fact, been done. Transfer a gene from one bacterium that is able to make use of a particular food, to another, and it makes the second bacterium more fit. It is the combination with a gene for antibiotic vulnerability that I wonder about.

I doubt you can speak of "a gene for antibiotic vulnerability". Every example that I've read involves a gene for antibiotic resistance, via expressing a protein that blocks the effects of a particular antibiotic in some way. The wild-type simply lacks that particular gene.

[Blind groper]

To Jim

You may be right, but I am aware that some GM bacteria have been engineered to be ultra vulnerable to certain toxins.

[mistermack]

To Jim

You may be right, but I am aware that some GM bacteria have been engineered to be ultra vulnerable to certain toxins.

Come on groper, give us some links. Don't be such a tease.

[Blind groper]

To mistermack

With the very best of intentions, I am not always able to do so. I subscribe to several science mags, and have done so for more than 20 years. Lots of stuff from those mags is swishing around in my little grey cells, but with no exact link to where it came from. That is why I made the last post vague.

[mistermack]

It's certainly not impossible to improve on what evolution has produced.
It's easier to picture why on higher animals, but I guess the same must apply to bacteria.

There are lots of things a designer could do better, but evolution can't do it, because the possible evolutionary route doesn't exist.

I don't know anywhere near enough about bacteria to say what might or might not be possible. I didn't know that people were already doing that kind of work.

[Tero]

Sorry mm, we here at Science have decided to deny funding for your project.

[mistermack]

Sorry mm, we here at Science have decided to deny funding for your project.

Yeh, yeh, I know what's going on.
The big drug companies have got to you. They don't want to lose their big payouts from developing and selling a continuous stream of new antibiotics.
Shame on you, just because there is less money in bacteria, and they are harder to patent.
You're not invited to my Nobel Prize award ceremony, so there!

[mistermack]

I see our dear leader, Superdave Cameron, was talking about the coming horrorshow, of resistant bacteria today on the news.

Somebody should tell him, it's been solved by a bloke on Rationalia.
He can get in touch if he signs up here.
I'd love to see him start posting.

[Scott1328]

I say we take off and nuke 'em from orbit. It's the only way to be sure.