some more information..
Kudos to the nice comments above!!
I thought since I am at a genetics conference I would add a few more parameters...
1) infection of humans
We simply cannot know this for sure. HOWEVER there is some very well researched biochemistry that suggests this is not likely....
Phages insert DNA into bacterial cells, and this is the method of "infection". The reason this works is because bacteria to a very large extent depend upon horizontal gene transfer i.e. DNA from other lysed bacteria will be taken up by bacteria. This is one trait that is exploited by humans for synthetic biology called "competence", by I digress...
Eukaryotics cells (including humans, of course!) if they see naked DNA will chew it up very fast. Naked DNA is a Bad Thing (tm), so a rogue phage that managed to get its DNA into a human cell, would have no "mechanism" for it to be integrated into the human genome; this is how viruses that "matter" work....
This is the intermission where I point out that MOST phages are DNA based, but not all...
Back to the main feature.
If you want to know how HARD it is for a virus to infect a human cell, look no further than the retroviruses....
This includes HIV...
The viruses are RNA (this is the bit that comes when you take DNA and set a polymerase on it, called transcription). So , you may ask, "how does this get past the human/euk surveillance". Well remember when we said that DNA is pounced upon? Well RNA is too (The enzymes Rnases are exceedingly good at their jobs as any lab person will tell you), only RNA in humans can be very long but also has evolved to be mobile (mRNA is messenger RNA), so mobile RNA is sort of "allowed".
But the tricky Retroviruses have an enzyme called "reverse transcriptase" which turns RNA back into DNA...and the worse thing is it uses the cell machinery!! Bang. We have a problem...
Biology is fascinating....
I must say when I first read this I wondered "how are they going to patent this?". Unless they have come up with a really clever piece of design software...
OK Beer, 'cos that's what this week is about ;-)
P.