
Superbugs Capable of Resisting the Strongest Drugs Found in Hospitals - caracaleo
http://refer.ly/superbugs-capable-of-resisting-the-strongest-drugs-are-spreading-through-us-hospitals/c/922bb802867c11e2bfbf22000a1db8fa
======
DanBC
The BBC programme "Horizon - defeating the superbugs" showed an experiment of
bugs developing resistance to antibiotics.

They had a large tray (about a metre by three metres?) divided into several
sections. At each end was regular gel food. Then in slices the gel had anti-
biotics dissolved in it in higher concentrations. In the middle they could not
dissolve any more anti-biotic, they had reached the solubility level. (This
would have been toxic for people). The bacteria had no problem evolving to
this level.

(<http://www.bbc.co.uk/programmes/b01ms5c6>)

Unfortunately, it's not available on BBC iPlayer anymore.

I ahem 'found' this clip on YouTube. (<http://youtu.be/2w38Ry1WHh0>)

------
jfoutz
I wanted to make a glib comment about overuse of antibiotics in farm animals.
Reading a little deeper, that 50% mortality rate is really scary. I guess,
those are people already in the hospital, so their immune system is already
taking a hit, but wow. 50%.

------
ChuckMcM
It is reassuring to me that while these "superbugs" are still outside of
people they are 100% susceptible to being destroyed by soap and scrubbing.

~~~
DanBC
For some values of "destroyed", including "not destroyed, just dislodged".

Obviously, washing hands with soap and water is important and helps reduce
infection. This CDC article has some information about some of the
difficulties with this. (EG: Why don't surgeons shower before surgery?) When
is clean too clean?
(<http://wwwnc.cdc.gov/eid/article/7/2/70-0225_article.htm>)

~~~
ChuckMcM
Generally soap destroys bacteria through acid-base reactions with the amino
acids in the bacteria. As a science experiment we took bacterial colonies we
had grown and exposed them to both an anti-microbial solution and a plain
soap. The anti-microbial solution causes the bacteria to die, and the soap
causes them to explode.

However, in heath care institutions it is impractical to use soap repeatedly
due to damage it causes to your skin (for the same reason it damages bacterial
cells, it is indiscriminate). Similarly with ultraviolet light sanitizers
which also work by destroying the cell material and are equally harmful to
your skin and bacteria.

There is an interesting investigation going on into encapsulation, basically
having health care professionals change gloves all the time which doesn't kill
the microbes on their hands but gives them fresh 'skin' each glove change.

~~~
tomkinstinch
> Generally soap destroys bacteria through acid-base reactions with the amino
> acids in the bacteria.

I'd like to learn more about what you mean by this, since everything from my
biology training has taught me that the mechanism of action of detergents is
primarily disruption of the lipid membrane of bacteria--ie. causing lysis and
release of cellular contents into solution[1]. The disruption is due to the
amphiphilic nature of detergent molecules (they are attracted to both polar
water molecules and to the non-polar lipid molecules in cell membranes,
ripping the lipids away with agitation of the solution). Amphiphiles are not
acid base so much as partially charge-polarized and capable of hydrogen
bonding, and partially charge/hydrogen bond neutral. Attaching to lipids and
water simultaneously is thermodynamically favorable for them.

It's true that bacterial S-layers are proteinaceous and provide some
protection, but detergents are still effective via the above mechanism (though
often more so in concert with EDTA, urea, or other agents).

Some bacteria (ex. _Streptococcus pneumoniae_ , _Klebsiella pneumoniae_ , some
strains of _E. coli_ ) have a capsule that would provide resistance to
detergents, but it is generally a structure made of polysaccharides, not amino
acids (ie. polypeptide). _Bacillus anthracis_ does have a polypeptide capsule
that would serve as a barrier to detergents, but it's an unusual
characteristic.

This is not to say that high or low pH (base or acid) cannot destroy bacteria,
but it is not the primary mechanism of action of soap or most so called anti-
microbial products. "Explode" is not quite the right word for soap (it would
be for hypo-osmotic lysis buffer). It really tears holes in the cell membrane.

Some anti-microbial soaps do contain agents that inhibit bacteria through a
mechanism other than lysis. Triclosan is in the anti-microbial soap commonly
found in hospitals, and it inhibits fatty acid synthesis--preventing bacteria
from forming cell membranes. It's typically combined with a detergent though.

Ultraviolet light sanitizers (254 nm light) knock some bonds loose in DNA,
causing thymine dimers to form. This doesn't quite destroy them, but it does
prevent them from replicating and can inhibit production of harmful gene
products by throwing a wrench in transcription.

You're right about soap overuse being damaging to skin, and glove changes are
important. One of the most simple changes I've heard suggested is a switch
back to brass doorknobs, since the copper kills bacteria via the oligodynamic
effect (still not very well understood).

1\.
[http://www.piercenet.com/browse.cfm?fldID=5558F7E4-5056-8A76...](http://www.piercenet.com/browse.cfm?fldID=5558F7E4-5056-8A76-4E55-4F3977738B63)

~~~
ChuckMcM
Nice!

Ok, so the acid-base explanation was the one we came up with after observing
what soap did to our bacteria under a microscope. The bacteria lost cellular
cohesion and became a sort of soup. In the case of anti-microbial soap the
bacteria simply ceased replicating (which we interpreted as them being dead).

Our test soap was SafeGuard brand (regular soap) and an antibacterial blend of
SoftSoap brand.

If you don't mind I'd like to borrow some of your explanatory text to augment
and/or replace some of the material in that experiment for other home
schooling parents.

------
lutusp
> The emergence of deadly, bacteria resistant hospital superbugs is on the
> rise according to the CDC.

Given this crisis produced by natural selection, it's amazing to think that
only 39% of Americans believe in evolution:

[http://www.gallup.com/poll/114544/darwin-birthday-believe-
ev...](http://www.gallup.com/poll/114544/darwin-birthday-believe-
evolution.aspx)

~~~
cobrausn
I'd say that number is probably higher - I know a number of people who believe
evolution happens but think that humanity didn't evolve from monkeys. Because
we are special, or something. I generally don't query further.

~~~
aethertap
I like to point out, when faced with that argument, that they are right! We
didn't evolve from monkeys, we evolved _with_ them from a common ancestor!
That doesn't seem to help though...

~~~
lutusp
> We didn't evolve from monkeys, we evolved with them from a common ancestor!

Yes, and (snicker, snicker) we therefore evolved from a creature that was
"lower" than a monkey. :)

------
killerpopiller
well, I am not sure, why it is on hackernews, but it growing resistances of
bacterias to antibiotics are indeed a huge problem.

If you think about giving birth to your next child in a hospital, think twice
about that. Multi resistant bacterias, like methicillin-resistant
Staphylococcus aureus are a danger.

A friend of mine and his newborn just had such complications to endure.

New research shows that 4% of hospital patients get infected anually in
Germany and another 4% dies from those complications.

~~~
tptacek
Yes, definitely have that C section performed at home. You definitely won't
need the services of a NICU available, either.

------
tel
While it's bad enough already, note that since bacteria can "hot swap" genetic
information it's the CR property itself which is surviving and spreading. This
is a pretty fascinating example of evolution at the sub-individual level.

