Z. apocalypsus
Squirming and writhing in unthinking hordes
That cannot be dented with bullets or swords –
They’ll find us and kill us and shred our remains,
They’re after our bodies and after our brains.
They’ll mess with our minds worse than Dali or Escher,
Our stomachs will turn and our bowels feel the pressure,
I sense in my gut that they’re here in the flesh –
Oh my…
Escherichia coli !
I feel a little bit guilty about the last line, as apparently the stresses should fall on the RIC and the CO, whereas I would prefer them to fall on the I and the LI (that is, the next sallybles along). But honestly, whoever actually ever says the name in full anyway ? So I reckon my stresses are every bit as valid.
E. coli, incidentally, is a natural part of our gut bacteria without which we would probably be dead. That is, until it turns bad…
On a completely different note, this seems like a good place to discuss horizontal gene transfer. This is where a (usually) bacterium grows a sex pilus which attached it to another of its species (or sometimes a completely different species) and exchanges genes, which may include a fancy new antibiotic resistance gene it happens to have mutated. My question is: why would it do that ? If its environment is suddenly flooded with penicillin, it’s surely to that one bacterium’s benefit to be the only survivor.
I cannot find a definite explanation online, but I do note that, for the most common method, the DNA that builds the pilus is a self-contained plasmid (that is, a part of the genome outside-of and independent-of the nucleus). It seems that the primary genes sent across are the very genes to want to poke its neighbours, and the other genes transferred are an accidental by-product. Therefore, the solution I tentatively propose is that, just like the mitochondria in our own cells, it started life as a parasite that over time has found it more advantageous to pay its host back for the netrients and shelter.
The plasmid would seem to be less far along this particular evolutionary journey in that it is not so intergrated into its host as to lose its own identity (as shown by their ability to pass between species) – basically they are freeloaders who don’t, I suggest, cause any problems for their hosts, and sometimes quite by chance cause an advantage. And of course, there’s no guarantee that it ever will be further subsumed, particularly as it seems to be spreading itself around just fine as it is. (Oh, and yes, I did just spell ‘intergrate’ with two Rs, and I just did so again…)
But I could be totally wrong. I just wish that a few of the articles marvelling at the outcome would give a thought to how we got here.
Rhyming Couplets 