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  • Antibiotics: behind the scenes, they enable much of modern medicine.

  • We use them to cure infectious diseases,

  • but also to safely facilitate everything from surgery to chemotherapy

  • to organ transplants.

  • Without antibiotics,

  • even routine medical procedures can lead to life-threatening infections.

  • And were at risk of losing them.

  • Antibiotics are chemicals that prevent the growth of bacteria.

  • Unfortunately, some bacteria have become resistant

  • to all currently available antibiotics.

  • At the same time, weve stopped discovering new ones.

  • Still, there’s hope that we can get ahead of the problem.

  • But first, how did we get into this situation?

  • The first widely used antibiotic was penicillin,

  • discovered in 1928 by Alexander Fleming.

  • In his 1945 Nobel Prize acceptance speech,

  • Fleming warned that bacterial resistance had the potential to ruin

  • the miracle of antibiotics.

  • He was right: in the 1940s and 50s,

  • resistant bacteria already began to appear.

  • From then until the 1980s,

  • pharmaceutical companies countered the problem of resistance

  • by discovering many new antibiotics.

  • At first this was a highly successfuland highly profitableenterprise.

  • Over time, a couple things changed.

  • Newly discovered antibiotics were often only effective

  • for a narrow spectrum of infections,

  • whereas the first ones had been broadly applicable.

  • This isn’t a problem in itself,

  • but it does mean that fewer doses of these drugs could be sold

  • making them less profitable.

  • In the early days, antibiotics were heavily overprescribed,

  • including for viral infections they had no effect on.

  • Scrutiny around prescriptions increased, which is good, but also lowered sales.

  • At the same time, companies began to develop more drugs

  • that are taken over a patient’s lifetime,

  • like blood pressure and cholesterol medications,

  • and later anti-depressants and anti-anxiety medications.

  • Because they are taken indefinitely, these drugs more profitable.

  • By the mid-1980s, no new chemical classes of antibiotics were discovered.

  • But bacteria continued to acquire resistance and pass it along

  • by sharing genetic information between individual bacteria

  • and even across species.

  • Now bacteria that are resistant to many antibiotics are common,

  • and increasingly some strains are resistant to all our current drugs.

  • So, what can we do about this?

  • We need to control the use of existing antibiotics, create new ones,

  • combat resistance to new and existing drugs,

  • and find new ways to fight bacterial infections.

  • The largest consumer of antibiotics is agriculture,

  • which uses antibiotics not only to treat infections

  • but to promote the growth of food animals.

  • Using large volumes of antibiotics

  • increases the bacteria’s exposure to the antibiotics

  • and therefore their opportunity to develop resistance.

  • Many bacteria that are common in animals, like salmonella, can also infect humans,

  • and drug-resistant versions can pass to us through the food chain

  • and spread through international trade and travel networks.

  • In terms of finding new antibiotics,

  • nature offers the most promising new compounds.

  • Organisms like other microbes and fungi have evolved over millions of years

  • to live in competitive environments

  • meaning they often contain antibiotic compounds

  • to give them a survival advantage over certain bacteria.

  • We can also package antibiotics with molecules that inhibit resistance.

  • One way bacteria develop resistance is through proteins of their own

  • that degrade the drug.

  • By packaging the antibiotic with molecules that block the degraders,

  • the antibiotic can do its job.

  • Phages, viruses that attack bacteria but don’t affect humans,

  • are one promising new avenue to combat bacterial infections.

  • Developing vaccines for common infections, meanwhile,

  • can help prevent disease in the first place.

  • The biggest challenge to all these approaches is funding,

  • which is woefully inadequate across the globe.

  • Antibiotics are so unprofitable that many large pharmaceutical companies

  • have stopped trying to develop them.

  • Meanwhile, smaller companies that successfully bring new antibiotics

  • to market often still go bankrupt, like the American start up Achaogen.

  • New therapeutic techniques like phages and vaccines

  • face the same fundamental problem as traditional antibiotics:

  • if theyre working well, theyre used just once,

  • which makes it difficult to make money.

  • And to successfully counteract resistance in the long term,

  • well need to use new antibiotics sparingly

  • lowering the profits for their creators even further.

  • One possible solution is to shift profits away from the volume of antibiotics sold.

  • For example, the United Kingdom is testing a model

  • where healthcare providers purchase antibiotic subscriptions.

  • While governments are looking for ways to incentivize antibiotic development,

  • these programs are still in the early stages.

  • Countries around the world will need to do much more

  • but with enough investment in antibiotic development

  • and controlled use of our current drugs,

  • we can still get ahead of resistance.

Antibiotics: behind the scenes, they enable much of modern medicine.

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抗生物質耐性の危機を解決するには?- ジェリー・ライト (How can we solve the antibiotic resistance crisis? - Gerry Wright)

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    Seraya に公開 2021 年 01 月 14 日
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