Superbug Epidemic in US - Now Threatening Canada

Originally posted by soficrow
kallikak

Back to the problem of microbial mutation.

Can you explain in simple language how mutation occurs, at the molecular level? What happens? What are the mechanisms and processes? What molecules are involved? What happens to the molecules?

Thanks.

sofi

Well... as I'm sure you are aware, microbial mutation occurs via a variety of mechanisms, from random changes in specific bases to insertion of large chunks of DNA at various locations within the genome.

However, the major mechanism driving the genetic change relevant to this thread is horizontal transfer of genes. Things like single nucleotide changes are not sufficient to drive the types of evolution that have been observed. What happens is akin to 'bacterial sex.'

Bacteria maintain a structure (pilus) that allows them to transfer DNA between each other, and probably most frighteningly often to other bacteria that aren't even closely related. Even more of a concern is that bacteria can transfer entire plasmids (extrachromosomal DNA that encodes for non-essential functions) that contain resistance for multiple antibiotics.

To make a long story short, a bacterium can become multiply antibiotic resistant more or less in under an hour.

Now the problem is that genes associated with virulence are being transferred on to plasmids and being similarly acquired by resistant bacterium. In theory, bacteria could pick up genes for resistance and virulence in 'sexual' event.

Additionally, the genes appear to be being transferred to strains that are either naturally more readily transferred to healthy hosts, or are more aggressive in their pathology... but this last point is merely speculation.

soficrow... you asked what molecules were involved. Interestingly large sections of DNA from the genome are often transported onto plasmids, so the derivation of plasmid genomes is a chimera of genes from other organisms.

James A. Shapiro at U of Chicago has characterized such behavior as natural genetic engineering, and I believe it's an accurate description.

Cells maintain not only intricate DNA repair systems, but systems that mobilize and translocate large regions of genomic DNA.

What will probably be of interest to you sofi, is the idea that cells also maintain a group of mutator polymerases... these enzymes induce mutation at higher rates than do regular polymerases, and are mobilized at very particular times... generally during what could be described as stress.

That was the long answer...

The short answer is that cells engage a process of natural genetic engineering that selects genes for survival and adaptation from a set of pre-existing genes that have been otherwise spliced out or removed from other bacteria.

Let me know if you have more questions you think I can answer.

Originally posted by Long Lance

...over-reliance on antibiotics, hmmm, feeding kilotons of antibiotics to cattle had nothing to do with the emergence of resistancies

but anyone who warns aganst the industry's madness is considered a doomsayer.

Uh huh. And this is only one of the monsters we created.

From the link above:

"The overprescription of antibiotics, and the use of antibiotics in animal feed, and use of antibiotics in all the cleaning products have created an environment whereby the weaker bacteria are dying off, leaving the stronger bacteria to be even stronger,"

We have antibiotics in everything - domestic animals, chickens are full of them - antibiotics are in our water, rivers...

No one really knows what happens when little teeny tiny bugs meet antibiotics in the wild, or when they mate in drug soup.

Thanks kallikak.

I was looking for simple language and accessible terminology - to 'hook' and inform readers without biology backgrounds. ...It's a hard job.

And oh yeah, I was hoping you'd mention proteins, not just plasmids.

Thanks, tho.

How about meat from aliens?

Antibiotics And Growth Hormones In Meat


"Wild" meat is the best. No antibiotics or growth hormones...

Here's another bit explaining how it all works.

How antibiotic resistant superbugs win out in the wild

The university team discovered that when low levels of antibiotics were introduced – as little as 15% of the level normally needed to kill the ordinary bacteria – the resistant strain became dominant after just a few divisions.

“In places like hospital corridors or wards, or on farms where antibiotics are routinely fed to cows in feedstock to limit infections, there is a constant low level exposure to antibiotics which encourages the resistant strains to succeed, especially if there are already a few resistant bacteria about”, says Dr Fleming and Mr Mc Cay....

Administering too low a level of antibiotics can cause a much more dangerous and long lasting infection by encouraging a resistant strain of bacteria to emerge. It is also important that the patient finishes their course of antibiotics so that infectious bugs are completely eliminated from the body. Disinfectant resistant bacteria are also emerging with increased use, and the scientists think this may be contributing to the problem through cross resistance.

Also - antibiotic soaps and lotions play a huge role in creating resistant bacteria. Plus, everyone who gets an antibiotic hit - animals and people - pees the extra out into our waste systems and waterways.

Which might help explain where the new virulent E. coli mutations came from, and why they now can infect plants...




PS. Very funny Hellmut. ...Good thread tho.



[edit on 4-1-2007 by soficrow]

Originally posted by soficrow
Thanks kallikak.

I was looking for simple language and accessible terminology - to 'hook' and inform readers without biology backgrounds. ...It's a hard job.

Hmmm.... simple language can be tough in molecular bio....

In any given population of bacteria a certain percentage will be resistant to antibiotics. Antibiotic resistance exists naturally as a consequence of the existence of antibiotics. In any case, use of antibiotics selects for those genes that encode antibiotic resistant proteins (antibiotics act generally on proteins). Use of antibiotics increases the presence of antibiotic resistance genes.

Through a process resembling sex, antibiotic resistance genes, virulence genes, and other genes can be transferred not only between bacterial species of the same type, but of between relatively unrelated bacterial species. Multiple genes may be transferred via any single 'sexual' event, further increasing the rate at which new traits 'evolve.'

And oh yeah, I was hoping you'd mention proteins, not just plasmids.

Sorry... I mentioned them above... though I know it wasn't in the context you were hoping. In any case... I don't exactly see the protein products as being entirely relevant to the horizontal transfer of resistance genes, unless you're talking about the apparatus that does the transferring. In any case, it sounds like you have a different perspective on proteins than I do, and I'd be interested in hearing it.

Originally posted by soficrow
Also - antibiotic resistant soaps and lotions play a huge role in creating resistant bacteria.

Don't even get me started on this stuff... BTW... triclosan has been found to accumulate in the tissues of higher mammals.

The ironic thing is that bacteria and exposing your kids to stuff... at least within reason, is better for them than sheltering them from it. Let 'em eat dirt.

Plus, everyone who gets an antibiotic hit - animals and people - pees the extra out into our waste systems and waterways.

Thing again is the vast majority of people who receive antibiotics shouldn't their immune system will deal with the problem... it might take a little longer, but in the interest of public health it's worth it.

I haven't had antibiotics in like 7 years.... and that was when I had surgery that included an allograft.

Which might help explain where the new virulent E. coli mutations came from, and why they now can infect plants...

I don't think anyone knows this yet... the hemmorhagic E. coli O157:H7 is unlike anything we've ever seen bacteria wise... scary indeed... I'd be interested to hear anything you might have with respect to the pathology of this bug.


[edit on 4-1-2007 by kallikak]

Originally posted by kallikak

Antibiotic resistance exists naturally as a consequence of the existence of antibiotics.

But surely you agree that we're doing a LOT wrong in our society - and forcing antibiotic resistance to develop?

Specifically - using human antibiotics in agricultural industries, marketing antibiotic cosmetics, etc. All at low level doses that select for resistance and virulence.

As posted above:

How antibiotic resistant superbugs win out in the wild

The university team discovered that when low levels of antibiotics were introduced – as little as 15% of the level normally needed to kill the ordinary bacteria – the resistant strain became dominant after just a few divisions.

“In places like hospital corridors or wards, or on farms where antibiotics are routinely fed to cows in feedstock to limit infections, there is a constant low level exposure to antibiotics which encourages the resistant strains to succeed, especially if there are already a few resistant bacteria about”, says Dr Fleming and Mr Mc Cay. “Our results suggest that hospitals need to re-evaluate the minimum levels of treatments they think will stop infections, and include data on the way bacteria are selected and survive as well”.

Administering too low a level of antibiotics can cause a much more dangerous and long lasting infection by encouraging a resistant strain of bacteria to emerge. It is also important that the patient finishes their course of antibiotics so that infectious bugs are completely eliminated from the body. Disinfectant resistant bacteria are also emerging with increased use, and the scientists think this may be contributing to the problem through cross resistance.

BTW - phages would mutate along with resistant bacteria. What do you think of going back to phages?

And oh yeah, I was hoping you'd mention proteins, not just plasmids.

Sorry... I mentioned them above... though I know it wasn't in the context you were hoping. In any case... I don't exactly see the protein products as being entirely relevant ... unless you're talking about the apparatus that does the transferring.

Exactly.

As you say, antibiotics target proteins - and they work by ...??? Doing what, precisely?


btw - I suspect prions are the primary mechanism required for the evolutionary process. So "prion pollution" can be seen as forcing evolution, as well as directing it.


.

Originally posted by soficrow
But surely you agree that we're doing a LOT wrong in our society - and forcing antibiotic resistance to develop?

Well... for the most part... but I am just being nitpicky. If you change the word develop to spread, I'll be in complete agreement.

Specifically - using human antibiotics in agricultural industries, marketing antibiotic cosmetics, etc. All at low level doses that select for resistance and virulence.

Yes... each one of these in its own way is contributing to the problem.

One thing that I've been meaning to mention and keep forgetting, but now seems as good a place as any... each person, each animal, etc. that receives a dose of antibiotic si effectively acting as a mini selective ecosystem. Sensitive strains are killed of, resistant strains remain behind. Resistant strains can then spread resistance to bacteria in the body that were formerly not resistant. In hospitals this is a huge problem... you have large amounts of antibiotics being used, with large amounts of resistant infection. In fact this is perfect man-made environment to breed antibiotic resistance.

To tell you the truth if someone said to me they wanted me to develop resistant bacteria, and assuming I had no moral code, and there were no laws against such things, the ideal scenario would be to combine a whole bunch of marginally compromised individuals, IOW immune-compromised due to age, illness, etc. Infect those people with bacteria that are resistant, then apply antibiotics over extended periods.

BTW - phages would mutate along with resistant bacteria. What do you think of going back to phages?

I think it's the sanest possible option in an insane medical community. I'm a HUGE proponent of phage therapy.... was hopeful that our own phage trials would have worked out better.

I think there are some problems that may need to be overcome... specifically related to delivery. Phages, being much larger than antibiotics will induce an immune response. Raw phages may be effective for a treatment or two, but once the immune system begins to recognize them, they'll be quickly destroyed.

I must admit though... I am not sure how much variation must exist to necessitate a new immune response. Perhaps different phage strains are adequate, but perhaps not. I would imagine that the issue of delivery is not viewed as an insurmountable obstacle though.

Exactly.

As you say, antibiotics target proteins - and they work by ...??? Doing what, precisely?

Depends on the antibiotic. Beta-lactams like penicillin and related drugs function by inhibiting cell wall synthesis. They act as a 'false substrate' and inhibit a class of enzymes known as transpeptidases. This action by itself is really only bacteriostatic... it doesn't kill existing bugs... just prevents effective replication... and is only active against rapidly dividing species. The cephalosporins function in a similar manner.

Aminoglycoside drugs, including things like streptomycin, spectinomycin, etc. function by inhibiting protein synthesis at the ribosome

Quinolones prevent DNA synthesis by binding to DNA Gyrase, preventing unwinding.

Rifampicin and other related drugs inhibit RNA polymerases and thus prevent transcription... so mechanisms of resistance are quite diverse.

btw - I suspect prions are the primary mechanism required for the evolutionary process. So "prion pollution" can be seen as forcing evolution, as well as directing it.

Prions? Really? Hmmm...

I suspect that non-random mutation driven by extracellular input is the mechanism for evolution. Indeed, I believe that not only the molecular evidence, but the fossil and other geologic evidence also suggests this.

I would be interested to hear your hypothesis about how protein misfolding is somehow retrotranslated back into the genome. It's interesting given that prions aren't necc. mutants.

Originally posted by kallikak

Originally posted by soficrow
But surely you agree that we're doing a LOT wrong in our society - and forcing antibiotic resistance to develop?

Well... for the most part... but I am just being nitpicky. If you change the word develop to spread, I'll be in complete agreement.

??? Nitpicky? ???

Factory farms routinely administer low level antibiotics to prevent acute disease. Which encourages resistant strains to emerge. Ie., develop.

Administering too low a level of antibiotics can cause a much more dangerous and long lasting infection by encouraging a resistant strain of bacteria to emerge.

sp and format

[edit on 5-1-2007 by soficrow]

Originally posted by soficrow
??? Nitpicky? ???

Factory farms routinely administer low level antibiotics to prevent acute disease. Which encourages resistant strains to emerge. Ie., develop.

Yes, just being nitpicky. It's nothing to get upset about.

Develop, in my mind doesn't properly encompass what's actually happening with antibiotic resistance. The genes don't need to be developed, they just need to be acquired. Genes for things like antibiotic resistance, and now even virulence, are generally acquired from other resistant bacteria... IOW, antibiotic resistance spreads from one antibiotic individual to some portion of the population.

Though like I said, it's really just me being nitpicky, and it's honestly nothing to get upset about. In the end we both reach the same conclusion, so the word choice is of little consequence. However... I am employed in a technical writing capacity, and it makes me a stickler for word choice. Sorry.



[edit on 5-1-2007 by kallikak]

Originally posted by kallikak

I am employed in a technical writing capacity, and it makes me a stickler for word choice. Sorry.

Reminds me of the Babel story in the Bible.

Language used to keep people apart, and ignorant. Not to mention as a tool of distraction and deflection.

Nasty little trap that can be.






ed to add comment


[edit on 5-1-2007 by soficrow]

Here is an informative article on ca-MRSA - and other bugs - from Macleans Magazine.

A recent edition of the Canadian Medical Association Journal (CMAJ) carried an unusually grim warning. A "pathogen combining virulence, resistance and an ability to disseminate at large," it cautioned, is poised "to emerge in force" in Canada.

Also, it causes pus-filled sores, lung abscesses and the occasional case of flesh-eating disease.

The bacterium is generally found inside the nose or on the skin of otherwise healthy people. An infection first appears as a red, tender area, then swells into a boil. When it's not treated properly, the abscesses spread and can grow to the size of "a grapefruit," one of the study's authors said.

From there, fever and other flu-like symptoms appear. In some cases, patients develop bleeding in the lungs.

The writer is rather self-consciously skeptical, but he does provide something of a contextual overview - even addressing H5N1, West Nile, and c. difficile.

ATS is not cited as a source.

Decided to check the news for updates. Found this:

Superbug 'apocalypse' warning

An expert in infection control warns today of a looming healthcare apocalypse as MRSA and other superbugs spread and the world runs out of antibiotics to treat those infected.

Richard James, director of a new national research centre dedicated to the fight against spread of infections, launched at the University of Nottingham yesterday, says there is an impending crisis on the horizon.

"We are facing a future where there will be no antibiotics and hospital will be the last place to be if you want to avoid picking up a dangerous bacterial infection - in effect, cut your finger on Monday and you'll be dead by Friday if there's nothing to prevent it," he says. "Quite frankly, the impending crisis on the horizon can be called the 'post-antibiotic apocalypse'."

More news - less sensational, but also alarming:

Medic warns of MRSA super bug danger to people rearing pigs
Brussels, Jan 6, IRNA

A Belgian doctor of microbiology and infectious diseases is warning of the danger to people rearing and handling pigs.

The warning by Dr. Bart Gordts of Sint-Jan Hospital in Bruges follows a case in which an abattoir worker in the Flanders region was infected with MRSA (methicillin-resistant Staphylococcus aureus) a multi-drug resistant bacteria the so-called super bug.

Today more and more pigs are carriers of MRSA bacteria, it noted.

***

MRSA lawsuits ten times higher than previously thought

New released figures show a rise in the number of MRSA-related compensation claims, raising questions as to whether the threat of litigation can be used as a policy instrument to pressure the NHS on infection control.

The NHS Litigation Authority has revised the number of cases involving healthcare-associated infections covering the period of April 2002 to March 2006 from seven to 68. It has also revealed that £5m was paid out in damages and £3m in costs during this time.

News of the payouts was welcomed by injury lawyers who are now using health and safety laws to hold the NHS accountable on MRSA. This is made possible because Control of Substances Harmful to Health (COSHH) regulations, that require employers to control exposure to hazardous substances to prevent ill health, also cover biological agents such as bacteria and other micro-organisms.

Maybe if enough lawsuits are threatened, the truth will be forced into the open. Then, we can start cleaning up our world.

:sigh:

Well, it would be nice.

Heterosexual transmission of community-acquired MRSA

Evidence has emerged of heterosexual transmission of community-acquired MRSA (methicillin-resistant Staphylococcus aureus. In the February 1st edition of Clinical Infectious Diseases investigators from New York provide detailed information on three heterosexual couples where there was evidence of sexual transmission of MRSA and also provide details of a prospective, community-based study involving individuals who had been diagnosed with community-acquired MRSA that found that the pubic region was the site of infection in 3% of cases.

And we haven't even mentioned c. difficile.

Whitewave was explaining in another thread about how viruses can hitchhike on bacteria. I already knew prions hithhike on viruses. ...So put them all together, it's a heck of a virulent soup.

...Superbugs that can be transmitted sexually, via ingestion, and they're airborne too - they're in bodily fluids, therfore in soil and water - and can be inherited too...

Sound familiar?

You read about this and wonder how to prepare, but it really doesn't hit home until it hits home.

Last February my 21 year old healthy son came over and told me he thought he'd pulled a muscle in his ribs. He went to the doctor and got some painkillers. That was on Friday. By Sunday he was in intensive care and had been diagnosed with MRSA. He was in congestive heart failure with fluid building up around his lungs and heart. They were hoping antibiotics would win the war but by Wednesday they had him in surgery and had to remove a part of his lung that had abcessed.

He's fine and healthy as ever now, but MRSA damn near killed him in just a few days time.

This is some extremely serious stuff we're discussing here, I know first hand.

Good thread

Thanks for sharing mrwupy.

I am sorry to hear about your son's experience - but very glad to know he's healthy now.

I know 3 people who got ca-MRSA - one was in a coma for weeks, and nearly lost her leg; one was on an antibiotic cocktail for almost a year. Fortunately, they all recovered too.

But unfortunately, many cases are NOT treatable. CA-MRSA kills. And we are running out of antibiotics that work against this and other superbugs.

Critics accuse the British doctor I quoted above as being "alarmist," but no - he's just telling the truth.

Better that we be informed, imo. Then we can prepare, and have a better chance of defending ourselves.

What are the symptoms of this? Does anyone know or have a link?

Also, why is it an epidemic, when I know of no one who has it?

Originally posted by ben91069
What are the symptoms of this? Does anyone know or have a link?

The links above list symptoms. Feel free to click on any one - more if you like. Or Google it.

Also, why is it an epidemic, when I know of no one who has it?

Hmmm.

Not quite sure how to answer that. Could you rephrase, please?

FYI - Community-acquired MRSA epidemics are reported in sports team members, military recruits, and children using daycare centres.

More information here:

Superbug "MRSA" Now Transmitted Sexually