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Bacteria are a problem in Hospitals. They cause infection,
infection often kills. Bacteria, rather inconveniently,
acquire antibiotic resistance. This is frequently achieved
through horizontal gene transfer... plasmids conveying
antibiotic resistance genes, and other advantageous
features,
may be taken up by bacteria allowing them to
flourish in an environment that they otherwise would not.
I propose swamping the environment with things that ARE
plasmids but also useless. They should code for
metabolically expensive proteins (fluorescent ones, so you
can find them?), useless peptides, or proteins that
inactivate existing antibiotic resistance mechanisms.
After a while, bacteria will adapt. They'll stop bothering to
acquire extrachromosomal DNA as it's now
disadvantageous in their environment. Who knows? they
may start secreting nucleases or something as a defense.
Either way, we're left with a much less lethal bunch of
bacteria.
O, and it goes without saying that the plasmids are not replication competent... that would just be re-inventing
the wheel-virus.
Blame everything on cats
http://www.bbc.co.uk/news/health-19474612
[Phrontistery, Sep 07 2012]
Achilles strain
The_20Achilles_20Strain
[bungston, Sep 15 2012]
[link]
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Plasmid-mediated gene transfer is usually driven by the plasmid itself. So you will need donor bacteria. And you will need the plasmid to be replicating in that bacterium, or it won't be there.
Now, using the gift of GM, it's possible to set things up so that the plasmid won't replicate vegetatively in other cells, and may be deleterious in recipient bacteria. But - you can't expect every cell to be a recipient. For example, non-growing cells are typically refractory. Conversely, at high growth (and dilution) rates, transfer alone is insufficient to maintain the infection.
If you did it constantly, you might well get mutants which were refractory to the transfer system you used. But there are a variety of transfer systems, performing in a range of different environments. So what you might then expect is the evolution or introduction of new resistance plasmids which avoided the block you'd introduced. |
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The real issue is that such systems will be under 100% efficacious, and for it to be a success you would need it to be 100%. That is - you're trying to stop evolution of multiply-resistant bacteria, and the only way to do that is make all pathogens refractory to plasmid transfer. Once a resistant strain has arisen, the proposed system does nothing to stop it. |
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I suppose you could still use such a system to detect presence of certain strains (perhaps with fluorescence), although there are generally other better ways of doing that. |
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If what you do is basically just dump a bunch of deleterious genes around the place, then yes, naturally competent cells would be selected against. But you'd be supplying a nice food source for the others. |
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That is of course apart from legal issues, which I won't consider here. |
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I'm not saying it's a bad idea to try and do things with plasmids vs antibiotic resistance, just that you need to think about how such strategies will play out. |
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it doesn't need to be 100%. Just 100% - the 99.9%
that Domestos kills. |
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How about coating the floor with a high Ca2+
solution then pulsing the entire hospital to 42C every
hour? |
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very small vertical partitions, to prevent the horizontal gene transfer. |
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The proportion of cells that take up DNA, whether
naturally, by transformation in a tube, or by
electroporation is absolutely vanishingly small.
(Next time you do a cloning experiment, work out
how many copies of your plasmid you put in, and
how many transformed colonies you get out.) |
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//it doesn't need to be 100%. Just 100% - the 99.9% that Domestos kills.// |
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Because you're trying to prevent production of a new strain with altered plasmids. Once such a strain has arisen, it can be selected for by antibiotics and take over regardless of your proposed system.
There will be lots of sources of bacteria which are outside your control - patients coming from different hospitals, visitors with community infections etc. |
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//The proportion of cells that take up DNA, whether naturally, by transformation in a tube, or by electroporation is absolutely vanishingly small.// |
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Conjugation on the other hand can be quite efficient - 0.1 per donor or more in a typical mating experiment. |
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//Fox Bacteria with crappy DNA// |
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So, like if Glenn Beck and Gretchen Carlson had a baby... |
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Or Mulder and Scully <surprised no one else hadn't mentioned this before..wanders away whistling the X-files theme tune> |
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Read another way, the title seems like a triple
redundancy, or a double tautology, or something. |
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Yes. read upside down, it looks more like "And yepac niw alretcap " something. |
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Read from behind the screen it says "Satan is my master". |
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A salvage to this system is to fox bacteria with dan
that is not crap but that gives an evolutionary
advantage. This advantage comes along with an
achilles heel you can use against them. A silimiar
scheme is linked.
One problem with this is that I am not sure how
stable plasmids are. You could (probably would)
have the advantageous dna and the achilles heel on
the same plasmid, but then lose the heel along the
way. |
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The achilles heel could be a reverse of the "Roundup
Ready" system--make the germs fitter, but weak to a
substance that doesn't greatly affect the
evolution/development of other strains, and then
apply the killer as needed. There's a risk of course of
breeding "superbugs" that way. |
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