Re: ipes! yo! blimey! good morning, Vietnam! hold the phone! wait! hang on!

[Guest guest]

How do you think this potentially translates to us? penny <usenethod@...> wrote: "They had previously spotted that one type of antibiotic, whichinterferes with DNA production in bacteria, causes release ofradicals. When they used a fluorescent dye that lights up in thepresence of hydroxyl molecules, the researchers were surprised todiscover that the same free radicals appeared if bacteria were treatedwith antibiotics that instead attack the cell wall or

theprotein-making machinery." Could this be part of a death program, rather than the cause of death?I recall a paper I studied about how some protozoan, killed withmetronidazole, shows certain hallmarks of self-destruction, such asDNA cleavage at regular intervals. It seems extremely unlikely thatmetronidazole itself would perform this periodic cleavage, though itdoes cleave DNA.This is from news.nature, by the way.One reason why apoptosis might exist in unicellular microbes (aparadox at first glance), would be to destroy viruses and thuspreserve kin. I'll definitely be scrutinizing this paper ASAP.>> "Antibiotics are known to attack different vital processes in> bacteria. But a study published in Cell1

today has revealed that three> major classes of unrelated drugs use the same ultimate weapon to> finish off the infectious critters. All of them force bacteria to> create killer bursts of oxygen-containing molecules called hydroxyl> free radicals.">

[Guest guest]

Wait!!!! There's more!!!!and i'll throw in a set of kitchen knives...

tony

> >

> > " Antibiotics are known to attack different vital processes in

> > bacteria. But a study published in Cell1 today has revealed that

three

> > major classes of unrelated drugs use the same ultimate weapon to

> > finish off the infectious critters. All of them force bacteria to

> > create killer bursts of oxygen-containing molecules called

hydroxyl

> > free radicals. "

> >

>

[Guest guest]

> How do you think this potentially translates to us?

Well, the actual molecular process of death in abx-treated bacteria

has received precious little scrutiny, perhaps chiefly because it's

not easy to figure out how to start in on it. So this is a quantum

leap for the field, the more so since the field barely exists. To me

it's as exciting as anything that's come out since I got into the

business.

Significantly related is the semi-recent and ongoing work of

Engleberg-Kulka in Israel. Her work seems to deal with a form of

bacterial apoptosis, but there's at least some controversy. The new

work may also represent apoptosis, but it's not clear. Main thing is

to understand the pathways on a nuts and bolts level, but it will

also be very helpful to figure out the cells' " intent " - whether it

is apoptosis.

A big question is how this translates to other bacterial groups.

These new guys studied only E coli & staph aureus, and their stuff

focuses on hydroxyl radicals, which I don't think can be formed

usually in anaerobes. And the molecules Engleberg studies are absent

in obligate parasites like chalmydia and borrelia. For now, I think

this stands as a real sore point. All bacterial taxa respond to abx,

on the whole, in about the same way, despite variations - there needs

to be some way to explain that commonality despite the probable non-

universality of these particular pathways now under study.

But in the end, this could be a door to very new kinds of

antibacterials... or not... but if so, they might sidestep the

phenotypic abx resistence I more or less blame for my predicament

(assuming bacteria are at the root of my situation). Those would be a

long way off, if they do ever come - so it's nothing to get excited

about really... people like me get excited a lot, yet material

advances always remain a lot rarer than exciting possibilities.

[Guest guest]

'

That translation is very interesting because I find established

colonies don't get killed easily. You think by throwing an antibiotic

on top of them they'll melt away- but this isn't so in my

experiences..I think I'm alway's getting my information from the

stopping them growing types of tests- like in a 6 antimcirbial discs

on a petri plate- which also displays strong growth tendencies in the

fields of low antibiotic distribution thru the agar. So established

infections with high numbers of bacteria need a specialised

understanding of what the real antimicrobial challenge truly is.

>

>

>

> > How do you think this potentially translates to us?

>

> Well, the actual molecular process of death in abx-treated bacteria

> has received precious little scrutiny, perhaps chiefly because it's

> not easy to figure out how to start in on it. So this is a quantum

> leap for the field, the more so since the field barely exists. To

me

> it's as exciting as anything that's come out since I got into the

> business.

>

> Significantly related is the semi-recent and ongoing work of

> Engleberg-Kulka in Israel. Her work seems to deal with a form of

> bacterial apoptosis, but there's at least some controversy. The new

> work may also represent apoptosis, but it's not clear. Main thing

is

> to understand the pathways on a nuts and bolts level, but it will

> also be very helpful to figure out the cells' " intent " - whether it

> is apoptosis.

>

> A big question is how this translates to other bacterial groups.

> These new guys studied only E coli & staph aureus, and their stuff

> focuses on hydroxyl radicals, which I don't think can be formed

> usually in anaerobes. And the molecules Engleberg studies are

absent

> in obligate parasites like chalmydia and borrelia. For now, I think

> this stands as a real sore point. All bacterial taxa respond to

abx,

> on the whole, in about the same way, despite variations - there

needs

> to be some way to explain that commonality despite the probable non-

> universality of these particular pathways now under study.

>

> But in the end, this could be a door to very new kinds of

> antibacterials... or not... but if so, they might sidestep the

> phenotypic abx resistence I more or less blame for my predicament

> (assuming bacteria are at the root of my situation). Those would be

a

> long way off, if they do ever come - so it's nothing to get excited

> about really... people like me get excited a lot, yet material

> advances always remain a lot rarer than exciting possibilities.

>

[Guest guest]

> '

> That translation is very interesting because I find established

> colonies don't get killed easily. You think by throwing an antibiotic

> on top of them they'll melt away- but this isn't so in my

> experiences..I think I'm alway's getting my information from the

> stopping them growing types of tests- like in a 6 antimcirbial discs

> on a petri plate- which also displays strong growth tendencies in the

> fields of low antibiotic distribution thru the agar. So established

> infections with high numbers of bacteria need a specialised

> understanding of what the real antimicrobial challenge truly is.

PS (prescript) to Bob... my previous message came thruough fine, I

just didn't reply for a long time.

I'm not sure that for most bacterial species you can clear the goo

once it's grown, even if you do lyse (break) the cells. I have read an

assertion that there is a ton of exopolysaccharides excreted from

cells when they grow on solid agar, and I am pretty sure that

polysaccharide absorbs a lot of visible light, and is thus visible.

Try putting something quite toxic and generally destructive on the

agar-grown cells, like 2% hydrogen peroxide... the visible " goo " may

remain unchanged. Of course, something really aggressive like a drop

of 6% sodium hypochlorite (bleach) might impact the goo, but perhaps

because it might actually degrade the polysaccharides in addition to

killing and presumably lysing the cells.

Liquid broth *does* clear up when the cells are lysed - I've been able

to confirm that from a few papers. I don't think much

exopolysaccharide is produced when they grow in liquid. Even so, I

don't understand exactly why lysis with say penicillin clears the

fluid. I don't know much about the absorbtion and scattering of light.

Anyway, Kim has remarked in a paper that if you take a cloudy

broth of bacteria and bomb in with penicillin, it clears right up. He

finds this amusing because back in the day there was a party that

thought penicillin was merely bacteriostatic. Apparently they missed

this experiment.

[Guest guest]

I have bombarded them with hydrogen peroxide and bleach, and

believe me they don't just clear up and disintegrate.

The problem in my humble oopinion is that bacteria are extremely

tough critters which manufacture toxic substances in industrial

chemical factories and many other industries, so to think they'll go

down to bleach, when they themselves manufacture acids, does sort of

make sense to me and that you need to be putting pressure on them-

especially when they are in a vulnerable situation, possably when

dividing...

>

>

> > '

> > That translation is very interesting because I find established

> > colonies don't get killed easily. You think by throwing an

antibiotic

> > on top of them they'll melt away- but this isn't so in my

> > experiences..I think I'm alway's getting my information from the

> > stopping them growing types of tests- like in a 6 antimcirbial

discs

> > on a petri plate- which also displays strong growth tendencies in

the

> > fields of low antibiotic distribution thru the agar. So

established

> > infections with high numbers of bacteria need a specialised

> > understanding of what the real antimicrobial challenge truly is.

>

>

> PS (prescript) to Bob... my previous message came thruough fine, I

> just didn't reply for a long time.

>

>

> I'm not sure that for most bacterial species you can clear the goo

> once it's grown, even if you do lyse (break) the cells. I have read

an

> assertion that there is a ton of exopolysaccharides excreted from

> cells when they grow on solid agar, and I am pretty sure that

> polysaccharide absorbs a lot of visible light, and is thus visible.

>

> Try putting something quite toxic and generally destructive on the

> agar-grown cells, like 2% hydrogen peroxide... the visible " goo " may

> remain unchanged. Of course, something really aggressive like a drop

> of 6% sodium hypochlorite (bleach) might impact the goo, but perhaps

> because it might actually degrade the polysaccharides in addition to

> killing and presumably lysing the cells.

>

> Liquid broth *does* clear up when the cells are lysed - I've been

able

> to confirm that from a few papers. I don't think much

> exopolysaccharide is produced when they grow in liquid. Even so, I

> don't understand exactly why lysis with say penicillin clears the

> fluid. I don't know much about the absorbtion and scattering of

light.

>

> Anyway, Kim has remarked in a paper that if you take a cloudy

> broth of bacteria and bomb in with penicillin, it clears right up.

He

> finds this amusing because back in the day there was a party that

> thought penicillin was merely bacteriostatic. Apparently they missed

> this experiment.

>

[Guest guest]

> I have bombarded them with hydrogen peroxide and bleach, and

> believe me they don't just clear up and disintegrate.

> The problem in my humble oopinion is that bacteria are extremely

> tough critters which manufacture toxic substances in industrial

> chemical factories and many other industries, so to think they'll go

> down to bleach, when they themselves manufacture acids, does sort of

> make sense to me and that you need to be putting pressure on them-

> especially when they are in a vulnerable situation, possably when

> dividing...

Yeah, I've been shown a paper suggesting that even the body's own

LL-37 kills bacteria primarily while they are dividing. This is a

surprise since most people think LL-37 probably forms a hole in the

membrane, which you'd think ought to kill them regardless... I mean

it's kind of like shooting an animal.

I'm not certain that 6% bleach or 2% H2O2 kills every form of every

bacterial species fully 100% (in fact I don't think they do), but they

certainly blow the living hell out of most stuff. I'm guessing that if

you drop a strong bleach solution on some bacterial goo and the goo

doesn't change, it's just the exopolysaccharides that are left (ie,

biofilm material), not living cells. Put plenty of bleach on the

entire plate and let it sit 45 minutes - then get a sterile loop and

see if you can subculture anything from the bleached plate onto a new

plate. Actually, that's not the greatest experiment, since along with

the cells you will transfer a bit of bleach, which could keep them

from growing even if they are still alive. I'm not sure how to get

around that problem without a centrifuge. Perhaps the bleach could be

neutralized with a reducing agent like N-acetyl cysteine, but I don't

really know how.

[Guest guest]

Remember that bacteria are manufacturing some pretty nasty and very

industrial types of agents and bleach is often mild in comparison.

There's also no drama for bacteria to live in stomach acid and go

thru like there's nothing there. There environemnts over eons have

made some species quite hardy.

tony

>

>

> > I have bombarded them with hydrogen peroxide and bleach, and

> > believe me they don't just clear up and disintegrate.

> > The problem in my humble oopinion is that bacteria are extremely

> > tough critters which manufacture toxic substances in industrial

> > chemical factories and many other industries, so to think they'll

go

> > down to bleach, when they themselves manufacture acids, does sort

of

> > make sense to me and that you need to be putting pressure on them-

> > especially when they are in a vulnerable situation, possably

when

> > dividing...

>

>

> Yeah, I've been shown a paper suggesting that even the body's own

> LL-37 kills bacteria primarily while they are dividing. This is a

> surprise since most people think LL-37 probably forms a hole in the

> membrane, which you'd think ought to kill them regardless... I mean

> it's kind of like shooting an animal.

>

> I'm not certain that 6% bleach or 2% H2O2 kills every form of every

> bacterial species fully 100% (in fact I don't think they do), but

they

> certainly blow the living hell out of most stuff. I'm guessing that

if

> you drop a strong bleach solution on some bacterial goo and the goo

> doesn't change, it's just the exopolysaccharides that are left (ie,

> biofilm material), not living cells. Put plenty of bleach on the

> entire plate and let it sit 45 minutes - then get a sterile loop and

> see if you can subculture anything from the bleached plate onto a

new

> plate. Actually, that's not the greatest experiment, since along

with

> the cells you will transfer a bit of bleach, which could keep them

> from growing even if they are still alive. I'm not sure how to get

> around that problem without a centrifuge. Perhaps the bleach could

be

> neutralized with a reducing agent like N-acetyl cysteine, but I

don't

> really know how.

>

[Guest guest]

>

> Remember that bacteria are manufacturing some pretty nasty and very

> industrial types of agents and bleach is often mild in comparison.

Like what? I haven't heard of this. Certainly some can produce acids,

but very weak and/or dilute acids are still called acids. Basically

anything south of pH 7 can be termed acidic, but even a humble can of

Coke has a pH around 2.5, close to that of the stomach. So an " acid "

can be up to 10,000 times milder than cola.

> There's also no drama for bacteria to live in stomach acid and go

> thru like there's nothing there. There environemnts over eons have

> made some species quite hardy.

> tony

I'm not certain about this, but my impression from a class on gut

pathogens was that most taxa experienced a big die-off in the

stomach... whether 90% or 99.99%, I don't know. Anyway, the pH of the

stomach is supposed to be one reason no one believed H pylori could

really live in the stomach. And I haven't heard of any other species

infecting the stomach. Some of those that pass thru the stomach may be

shshielded inside food particles.

[Guest guest]

Cyclon b, the stuff used in the german gas chambers is an egs of

bacterial industrial compounds- as one that comes to mind. The other

egs I can recall is bacteria thrown into a toxic site to clean it

up..So you go to some toxic dump and thorw bacteria in to clean it up-

the bacteria can obviously handl;e the toxic site and consume and

neutralise the crap in the area.

Vats with certain bacteria are a frequent observation in many russian

chemical plants creating all sorts of substances used in many

applications..

tony

>

>

> >

> > Remember that bacteria are manufacturing some pretty nasty and

very

> > industrial types of agents and bleach is often mild in

comparison.

>

> Like what? I haven't heard of this. Certainly some can produce

acids,

> but very weak and/or dilute acids are still called acids. Basically

> anything south of pH 7 can be termed acidic, but even a humble can

of

> Coke has a pH around 2.5, close to that of the stomach. So

an " acid "

> can be up to 10,000 times milder than cola.

>

>

> > There's also no drama for bacteria to live in stomach acid and go

> > thru like there's nothing there. There environemnts over eons

have

> > made some species quite hardy.

> > tony

>

> I'm not certain about this, but my impression from a class on gut

> pathogens was that most taxa experienced a big die-off in the

> stomach... whether 90% or 99.99%, I don't know. Anyway, the pH of

the

> stomach is supposed to be one reason no one believed H pylori could

> really live in the stomach. And I haven't heard of any other

species

> infecting the stomach. Some of those that pass thru the stomach may

be

> shshielded inside food particles.

>