Super Bacteria? Fighting Resistance Could Be Trickier Than Thought

A process thought to hamper antibiotic resistant bacteria, one of the world's most pressing public health problems, might actually make them stronger, according to a new Portuguese study that could signal a dramatic shift in our understanding of bacterial resistance.

Though much is still unknown about the exact mechanics involved, bacteria become resistant to antibiotics via chromosomal mutations and the incorporation of new genes, sometimes from other bacteria.

Researchers had believed that the acquisition of new genes conferring resistance has come at some cost to the bacteria, making it tougher for them to reproduce and survive.

But the authors of the new Portuguese study found that when already resistant bacterial cells obtain another antibiotic-resistance gene from a small piece of DNA called a plasmid -- a development that has been thought to have some cost to the host -- the cells sometimes divide faster than before.

Francisco Dionisio of the University of Lisbon, one of the study's authors, said the results, which focused on the bacterium E. coli, were unexpected.

"It is as if your PC with a mistake or bug in the operating system began to run faster after receiving a computer virus," Dionisio explained in an email to The Huffington Post.

"This happened 52 percent of the cases studied," he added. "And we expected zero percent!"

Other experts echoed Dionisio's surprise.

"It has always been an understanding that the acquisition of these resistant genes comes at some cost, so that the bacteria that have picked up these extra genes have extra baggage, so to speak," said Dr. Arjun Srinivasan, associate director for healthcare associated infection prevention programs at the Centers for Disease Control. "That this might actually make them more fit and able to divide more quickly is a real change."

But the good news for resistant bacteria isn't good news for public health. The findings suggest that curbing antibiotic resistant bacteria -- already a top public health issue, according to the CDC -- may be even more difficult than previously thought. Dr. Jan Patterson, president elect of the Society for Healthcare Epidemiology of America, called the results "concerning." She added that the results could signal a shift in future research and control efforts.

"The finding brings up that just controlling antibiotic use alone is not going to take care of the problems of emergence and persistence of resistance," Patterson said. "We might have to start looking at other ways to fight bacteria, like inhibiting production of plasmids or inhibiting how bacteria divide."

To her knowledge, Patterson said little or no research has been done in that area. In the meantime, she pointed to methods like hand hygiene as a means of limiting the spread of resistant bacteria, particularly in hospitals, where the number of resistant strains is on the rise.

The CDC has identified improving in-patient antibiotic use as priority. It says that 50 percent of antimicrobial use in hospitals is "inappropriate," meaning antibiotics are used when they are not needed or they are administered the wrong dose. Increasing use of antibiotics increases the prevalence of resistant bacteria in hospitals, a recent CDC report stated.

Other broad areas of focus when it comes to preventing antibiotic resistance include limiting the use of antibiotics in farm animals, including pigs and cows.

"The prophylactic and potentially careless use of antibiotics on such a large scale provides perfect breeding ground for drug-resistant strains," said Gunnar Kaufmann, assistant professor of chemical immunology at The Scripps Research Institute.

Such efforts to curb antibiotic use and increase things like hand washing in hospitals will have to suffice for now, the experts agreed, as the public waits for more research on exactly how antibiotic resistance works to be funded so that it has a better chance of being stopped.

"Medicine is a study in humility," Srinivasan of the CDC added. "We learn every day that something we thought was true is not correct. A study like this simply calls upon us to recognize the fact that we don't know everything we need to know yet. We need more investment in these problems."

RELATED:

Comments

[deckercat]

07:59 AM on 08/01/2011

i read some where that the number of virus caused diseases we've cured is zero. anybody know if this is so?

[Thermoguy]

01:43 AM on 08/01/2011

As part of a science based group that lectures medical academia, we reported through the Canadian Government there was a product that would deal with MRSA and it was non toxic. The frustrating part for our director was they didn't get a response at all when we weren't selling anything, we were just reporting to the authority.

The product was so successful with bacteria, they witnessed bacteria blowing up with an electron microscope and his quote was there wasn't a cell left to divide. Sad but true.

[C Karen Stopford]

09:34 AM on 07/31/2011

What they fail to mention is that the faster cells multiply, the more likely they are to further mutate and therefore create novel, resistant strains. F--- with nature and it will bite you, every time.

[Ozark Homesteader]

11:51 AM on 07/30/2011

I thought that oil of oregano was pretty darn good at killing mutating drug-resistant bacteria. Will it have the same issues?

[mark whitehouse]

05:56 PM on 07/29/2011

the implication here is that gene manipulation enhances bacterial vigour
consider the amount of engineering going on -
this might explain why colds and flu's seem to be getting more virulent

[Dream Job Maven]

02:55 PM on 07/29/2011

Why does the medical industry, and Government Health agencies, always look for a biological remedy to control antibiotic-resistant microbes, and totally ignore the research around non-toxic, water-based organosylane products that can mechanically inhibit their growth, without causing incidious mutations?

It may be worthwhile investigating the few companies that produce such products, e.g., BioShield, GoldShield, SaniShield.

[Shain Eighmey]

09:39 PM on 07/29/2011

1. Non-toxic? I'll be honest, I'm speculating here, but I'm less than convinced that those products are non-toxic when you consider the problems of leeching.

2. You have the cause and effect relationship of mutations all backwards.

[ijgibson]

02:15 PM on 07/29/2011

Before retirement I used to teach a course to final year Biology undergraduates in the UK on bacterial drug resistance and plasmids. This really isn't new - I retired in 1993 ! In the post Dionisio says the presence of the plasmid caused faster growth - "This happened 52 percent of the cases studied," he added. "And we expected zero percent!". That means that it didn't happen in 48%. Easily within experimental error this actually means the plasmids had no effect on growth !!
A big campaign ran in the UK about inappropriate use of antibiotics in medicine in the '80's. One of the worst ways they were spread was the practice, when filling syringes, of expelling the air from the syringe along with an aerosol of the antibiotic straight into the hospital atmosphere ! As for "when it comes to preventing antibiotic resistance include limiting the use of antibiotics in farm animals, including pigs and cows." Add in chickens and the UK passed a law to ban any of the antibiotics used in human or veterinary practice from animal feeding regimes in the early 80's. Most of this post seemed horribly dated !!

[mark whitehouse]

06:01 PM on 07/29/2011

"no effect on growth!!"???
you should know the slower ones retreat, the faster ones overtake
a change in the "variation -rate" in the culture doesnt average out to "the same"

[ijgibson]

05:41 AM on 07/30/2011

But when ~50% grow faster and 50 % don't - that doesn't suggest to me that there's any significant difference overall ! I'd be much more impressed with the 'new discovery' if 75% grew faster

[spitoon]

12:57 PM on 07/29/2011

Wtf. Any freshman biology student can tell you this. This isn't news.

[Brad T Casali]

09:52 PM on 07/29/2011

Presumably, you're referring to a mutation that confers resistance to a bacterium. This is not new.

However, this study explains how an extra mutation can confer an even greater resistance if a different, antibiotic-resistance mutation is present. This is essentially epistasis which is different than the traditional stuff a 'freshman' biology student learns.

This article is poorly explained and does not accurately reflect what PLOS published.

[spitoon]

03:16 PM on 07/30/2011

Oh, sorry about that.

[NoRhymeOrReason]

12:32 PM on 07/29/2011

Wouldn't it be ironic if the failure of our healthcare system resulted in the reduction in the use of antibiotics, which, in turn, caused humans to rely on and thereby strengthen their own immune systems and thereby rendering the superbugs ineffective?

[edejan]

12:44 PM on 07/29/2011

Our food system is so loaded with antibiotics given to livestock that individual use of antibiotics is probably the lesser part of the problem. I now look for meat with a label indicating that no hormones or antibiotics were fed to the animal.

[Alex Cheng]

01:11 PM on 07/29/2011

TBH, if you think just avoiding consuming animals that were raised without hormones or antibiotics would prevent you from ingesting antibiotics unknowingly, you're wrong. Our drinking water (tap) is loaded with antibiotics and medication from either people flushing expired medication down the toilet or unmetabolized medication that pass through people's bodies.

[Shain Eighmey]

09:41 PM on 07/29/2011

It doesn't work like that unfortunately. They're no less super even if we don't challenge them.

[Youcantstandthetruth]

12:28 PM on 07/29/2011

Don't the baggers want to get rid of the CDC. They view it as wasteful goberment spending.

[nomadrdw]

12:02 PM on 07/29/2011

it will all come down to the profit motive. our farms use more antibiotics than the rest of civilization altogether in the name of profit. small daily doses of antibiotics let them feed the animals food that they are NOT meant to eat, and keeps them gaining weight fast enough to be slaughtered for market before the meds actually kill them because of what they are doing long term.

[jayemjay]

11:53 AM on 07/29/2011

Regarding overuse of antibiotics in factory farms... farming in this brutal, nonsensical way is much more profitable in the short-term, so short-term thinking wins. The future costs to the environment and public health are never factored into the money calculation. In this country money talks and money sets policy. The public is brainwashed into going along on the promise of cheap goods. We are going the way of all collapsed civilizations. Read Jared Diamond's book, "Collapse: How Societies Choose to Fail or Succeed."

[Mark Knudsen]

01:27 PM on 07/29/2011

so all you people know this when are y ou goimg t do somethign besides talk and don't give me this "i dont have any power" you h ave the power just claim it and get on with it..but I have been round this tree with you so many times I'm dizzey the old viking

[jayemjay]

07:32 PM on 07/29/2011

I have cut down on animal product consumption and try to buy locally, where I have some idea of how the animals are farmed. I have joined these two movements to try to do something about corporate influence on government:

http://movetoamend.org/
http://www.rebuildthedream.com/

I also regularly contact my representatives in government and vote. I hope concerned people will do the same and give other suggestions.

[MarinafromMaine]

11:38 AM on 07/29/2011

It is only since the advent of the sale of antimicrobial soaps to the general public that these super-resistant bugs have become rampant. I believe that the use of antimicrobial soaps by the public is partly responsible for the increase in resistant bacteria.

There is no indication that these soaps actually reduce the risk of infection any more than hand-washing with regular soap. However they do induce resistance to bacteria that were previously easily treatable, as well as kill off benign bacteria that compete with harmful bacteria.

Antimicrobial soaps should be banned for use by the general public. If you're using them, you're actually putting yourself, and everybody else, more at risk.

[edejan]

12:45 PM on 07/29/2011

Good point. Thanks! Fanned and faved.

[D-blings]

01:12 PM on 07/29/2011

That's partly it but the main factor is that we feed our children antibiotics as if they are Flintstones vitamins.

[M4dwoman]

11:21 AM on 07/29/2011

We are but one wealthy mad scientist away from a biological disaster. Read Herbert's The White Plague.
Bacterial genes are easy to manipulate, but apparently these simple organisms themselves aren't.

[den1953]

11:19 AM on 07/29/2011

This must explain why Washington is in the state it's in today?

[McGyver1]

11:26 AM on 07/29/2011

That's because American workers used to make things.

Get back to where you once belonged...Beatles.

[den1953]

12:44 PM on 07/29/2011

I suppose that is what is meant by profit over country? F