Category Archives: Antibiotics

Antibacterial Products May Do More Harm Than Good

photo of a dandelion

Strange but True: Antibacterial Products May Do More Harm Than Good by Coco Ballantyne:

Unlike these traditional cleaners, antibacterial products leave surface residues, creating conditions that may foster the development of resistant bacteria, Levy notes. For example, after spraying and wiping an antibacterial cleaner over a kitchen counter, active chemicals linger behind and continue to kill bacteria, but not necessarily all of them.

When a bacterial population is placed under a stressor—such as an antibacterial chemical—a small subpopulation armed with special defense mechanisms can develop. These lineages survive and reproduce as their weaker relatives perish. “What doesn’t kill you makes you stronger” is the governing maxim here, as antibacterial chemicals select for bacteria that endure their presence.

Pretty basic understanding of evolution makes the breeding of very resilient bacteria a fairly obvious result. One thing that might not be as obvious until it is mentioned is that by killing off the “weaker” bacteria you also provide a niche for the more resilient bacteria to multiply and fill the gap left by the bacteria that were not a problem that were killed off. Imagine if, instead of digging out the 3 dandelions you wanted to remove from your yard, you removed all plants from your yard (including those 3 dandelions). I would bet most often that would result in more dandelions not fewer as the dandelions were able to fill in the void of plants in the yard.

In general, however, good, long-term hygiene means using regular soaps rather than new, antibacterial ones, experts say. “The main way to keep from getting sick,” Gustafson says, “is to wash your hands three times a day and don’t touch mucous membranes.”

Tuberculosis Risk

We have posted about the Tuberculosis risks previously: Extensively Drug-resistant Tuberculosis (XDR TB), May 2007 – Deadly TB Strain is Spreading, WHO Warns, Mar 2007 – Tuberculosis Pandemic Threat, Jan 2007 – ‘Virtually untreatable’ TB found, Sep 2006. One USA citizen, while infected with XDR TB, flying to Europe and then to Canada and driving back into the USA has created a huge amount of publicity on this topic in the last week.

The risks are well known, given the extreme mobility in the world today, for TB, and other communicable diseases, becoming more troublesome, costly and deadly – often due to improper antibiotic use. But we continue to avoid giving this risk near the level of attention it seems to deserve. Deaths due to these diseases is likely to be very high in the next 20 years.

In fact there were 1.6 million TB deaths in 2005 (see WHO fact sheet below). Even if you only care about deaths in the USA (I am not advocating such a position, but even for those that hold such a position…) failing to address these issues will greatly increase the odds of large numbers of deaths in the USA (for TB and other diseases that become difficult or impossible to treat with antibiotics).

The current news will do little in my opinion (though it will help raise awareness). It will take a significant number of deaths in the USA, for significant policy changes to be implemented. Luckily scientists and policy makers have been giving these risks thought and so possible actions are already fairly well know. Unfortunately we seem very inclined to ignore problems for those out of sight (either continents away, or in the future) so until the consequences of the current action forces people to confront this issue little has been done (well actually good action is being taken, but much more is left to do).

One huge issue is quarantine. Personally, I try to use as a guide that people have the right to do what doesn’t infringe upon others rights. This allows plenty of room for debate about what level of trade-off is acceptable but I find it a useful guide to shape my thoughts. People don’t have the right to drive drunk and endanger others. People don’t have the right to pollute the air of others by smoking (or polluting the air with dangerous chemicals, CO2…). People don’t have the right to expose others to dangerous communicable diseases. Doctor’s don’t have the right to proscribe antibiotics when not medically justified (creating risks to those in the future)… But how society decides to define the social contract that everyone must agree to (rather that a way I find useful to help me analyze what is reasonable) is in need of some increased clarity in the light of health care issues today.

World Health Organization fact sheet on Tuberculosis:
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Evolution In Action

the way they watched the process was to sequence the whole genome of each bacterial isolate. What they found were a total of 35 mutations, which developed sequentially as the treatment continued (and the levels of resistance rose). Here’s natural selection, operating in real time, under the strongest magnifying glass available. And it’s in the service of a potentially serious problem, since resistant bacteria are no joke. (Reading between the lines of the PNAS abstract, for example, it appears that the patient involved in this study may well not have survived).

The technology involved here is worth thinking about. Even now, this was a rather costly experiment as these things go, and it’s worth a paper in a good journal. But a few years ago, needless to say, it would have been a borderline-insane idea, and a few years before that it would have been flatly impossible. A few years from now it’ll be routine, and a few years after that it probably won’t be done at all, having been superseded by something more elegant that no one’s come up with yet. But for now, we’re entering the age where wildly sequence-intensive experiments, many of which no one even bothered to think about before, will start to run.

Very interesting. He is exactly right that the technology advances continuing at an amazing pace allow for experiments we (at least I) can’t even imagine today to become common in just a few years. And the insights from those experiments will allow us to think of new experiments… Wonderful.

Extensively Drug-resistant Tuberculosis (XDR TB)

Superbug poses dire threat to Africa

The journey to Dr. Moll’s terrifying discovery began in early 2005, when he noticed something peculiar. The staff at his hospital had become accustomed to the marvellous “Lazarus effect” of anti-retroviral treatment for AIDS: seeing desperately sick people quickly start gaining weight and return home or go back to work. But now, in his ward, he had two men in their 30s on ARVs whose HIV infections were suppressed to undetectable levels. Yet their TB, which would normally have cleared up in a matter of weeks, kept getting worse.

He suspected multidrug-resistant TB, or MDR, believed at the time to be as bad as the disease could get. So he collected sputum from 45 patients and sent it off to a lab in Durban for cell culturing. (The only way to tell if a TB strain is drug-resistant is to grow cultures from a patient sample, zap it with the different drugs and see which, if any, fail to kill it.) The process takes six to eight weeks. “In that time, we more or less forgot about it,” Dr. Moll said. One of his two young men died.

But the phone call from the lab, when it eventually came, slammed the issue to the top of their agenda: Of the 45 samples, 10 were indeed drug-resistant. But they weren’t resistant to just one or two of the drugs used against TB. They were resistant to all six medications available for use in Tugela Ferry. In other words, there was nothing to cure that TB at all.

As we have discussed previously, antibiotic resistance is a huge problem today and especially looming in the future. Perhaps we will find new fantanstic cures but the failure to take sensible action puts us at great risk.

Being Bad is Best for Bacteria

That conclusion is based on the first experiments investigating how natural selection influences the transmission of infectious disease. The outcome of those experiments defies old assumptions that pathogens evolve to become less infectious
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The scientists analyzed the patterns of disease transmission and found that strains of bacteria with the greatest damage to their virulence genes were slowest at spreading from one host to another. The strain of pathogen with all of its virulence genes intact spread the fastest. Strains of pathogen lacking the ability to inject any proteins into the host were completely unable to spread between hosts, suggesting that these swapped virulence genes are essential for spread.

Hacking Your Body’s Bacteria

Hacking Your Body’s Bacteria for Better Health by Brandon Keim

In sheer numbers, bacterial cells in the body outnumber our own by a factor of 10, with 50 trillion bacteria living in the digestive system alone, where they’ve remained largely unstudied until the last decade. As scientists learn more about them, they’re beginning to chart the complex symbiosis between the tiny bugs and our health.

“The microbes that live in the human body are quite ancient,” says NYU Medical Center microbiologist Dr. Martin Blaser, a pioneer in gut microbe research. “They’ve been selected (through evolution) because they help us.” And it now appears that our daily antibacterial regimens are disrupting a balance that once protected humans from health problems, especially allergies and malfunctioning immune responses.

Deadly TB Strain is Spreading, WHO Warns

Deadly TB strain is spreading, WHO warns:

Africa’s large AIDS population is at special risk from the particularly virulent strain, known as XDR-TB (extremely drug resistant), which had been documented in 35 countries worldwide, 16 of them in this year. “This is the most urgent thing I have seen in my 15 years of working on tuberculosis,” said Mario Raviglione, director of the STOP TB program at the World Health Organization. He introduced WHO’s TB report, which coincides with the 125th anniversary of the discovery of the microbe that causes TB.
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Some 2 billion people worldwide live with TB, an airborne illness that is normally treatable through inexpensive medication. But if the disease is not diagnosed and treated, it can mutate into drug-resistant strains. In 2005, nearly 9 million people became infected with tuberculosis and 1.6 million died of it, about the same as the year before, which showed that containment efforts were working, Raviglione said. The epidemic is centered primarily in Asia and in Africa, which accounted for 84 percent of the total.

“The good news is that the global incidence may have peaked,” particularly in China, India, and Indonesia, he said. “The bad news is that although the incidence has declined [there] is resistance to most powerful first-line drugs and a form of TB that is resistant to second-line drugs.”

Antibiotics Too Often Prescribed for Sinus Woes

This is not one of the more amazing articles, rather one more in the long line of those reporting on the overuse of anti-biotics: Antibiotics Too Often Prescribed for Sinus Woes:

But it’s hard to preach that wisdom to someone with a drippy, hurting sinus who wants immediate relief, Leopold acknowledged. Because more effective drugs are lacking, “patients are desperate, physicians are desperate, and it is not a happy situation,” he said.

I guess I am just out of touch but why do physicians think it is ok to practice bad medicine because people will whine if they try to practice sensible medicine? These stories often tell of doctors that can’t say no to patients even if it means going against what is the best medical advice. Is it any wonder that helath costs continue to escalate, now totaling 16% of GDP, with such practices accepted? How hard is it to say, yeah great you want x drug, that is not medically advisable and is only available by prescription because it is not advisable for people to decide they need it but rather physicians are suppose to make that decision.

And so the physician often makes the practical choice of giving what the patient wants, with a chance of relief, over the more abstract issue of antibiotic resistance, he said.

I understand this reality. I just find it very sad that that professionals sacrifice the future to today’s ignorance and short sightedness. I wish physicians would not reward those demanding they get what they want today since they are simultaneously condemning others to suffer the consequences of such decisions.

But I also want us to stop spending our grandchildren’s money today. Still the politicians act just like the physicians choosing to give the voters what they want today and let someone else deal with the consequences later. Current USA federal deficit: $8,841,291,672,873 (see live debt clock), $29,349 for every citizen of the USA. It seems pretty obvious the same willingness to sacrifice the future for an easier life today is at the root of the actions by both doctors and politicians. Thankfully some are trying to counter this behavior, by both parties, to varying success.

Attacking Bacterial Walls

Bacterial Walls Come Tumbling Down:

Penicillin and many newer antibiotics work by blocking a piece of the machinery bacteria use to construct their durable outer walls. Without these tough, protective coatings, bacteria die. The enzymatic machinery (known as PBP2) studied by Strynadka’s group has two main parts: One end assembles long sugar fibers; the other end stitches them together with bits of protein to form a sturdy interlocking mesh shell.
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“This enzyme is an awesome target for antibiotics,” said Strynadka. “We have a totally new understanding of how the enzyme works and how a very good animal antibiotic inhibits the enzyme.” Although moenomycin is poorly absorbed by the human body, the new understanding of exactly how it interferes with bacterial enzyme function should help scientists design modified versions that are more suitable for use in people.

Understanding the structure of this enzyme should also speed up screening and design of new antibiotics, which are in constant demand as microbes continually evolve new ways to evade the drugs that researchers design to thwart them. The time it takes for bacteria to develop resistance to new antibiotics has been as short as one year for penicillin V and as long as 30 years for vancomycin.

FDA May Make Decision That Will Speed Antibiotic Drug Resistance

FDA Rules Override Warnings About Drug:

The government is on track to approve a new antibiotic to treat a pneumonia-like disease in cattle, despite warnings from health groups and a majority of the agency’s own expert advisers that the decision will be dangerous for people. The drug, called cefquinome, belongs to a class of highly potent antibiotics that are among medicine’s last defenses against several serious human infections. No drug from that class has been approved in the United States for use in animals.

This is why it is so important for government decisions that require scientific knowledge be made by knowledgeable scientists.

But Sundlof said that under FDA rules, those decisions must be left up to veterinarians unless there is clear evidence that wider use is causing harm.

“That is our policy” is not a good excuse for endangering public health. The dangers of anti-biotic resistance are obvious, well known, we see the results of bad decisions in the past creating havoc today and still government wants to act as though the inevitable consequences of their actions are somehow out of their hands. A policy that will lead to the deaths of many people should be fought. If you want to claim this policy will not do that, then make that argument. Don’t claim some policy prohibits you from saving lives.

Democratic/Republican forms of government give politicians oversight over bureaucracy to guide decisions for the public good. When politicians don’t understand basic science (in this day and age – when decisions require that understanding) that can lead to very dangerous policies. You would think that adults would be able to understand that just because consequences will be delayed a few years that doesn’t mean you should allow special interests to get what they want today. But the deficit (nearly $8,800,000,000,000 for the federal government now) provides a visible sign how much they care about future consequences of their actions. Combine that with little scientific understanding and that is not a prescription for good decisions.
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