As dystopian visions go, a world without antibiotics might not sound catastrophic. But unlike, say, a zombie apocalypse, losing the ability to defeat microbes really could kill tens of millions. What’s more, it’s a looming risk.
Already, there are some infections for which we’re reaching the last lines of pharmacological defence. And given how fast bacteria develop resistance, these treatments might not last long.
There is no reason for panic, however—or at least, not quite yet. New antibiotic drug therapies and other anti-bacterial treatments are being developed, some of which have the potential to be more durable than those have served us so well for the past three-quarters of a century.
These include the extraction of potent antibiotic chemicals from other bacteria, the development of bacteria-killing viruses, of new vaccines that allow the body to better fight foreign bugs and of coatings that prevent bacteria from colonising surfaces before they can spread.
Speeding up science
Drug-resistant infections are on the rise—by one count they already kill 700,000 people a year, which, if the trend continues, will rise to 10 million within 30 years.
Drug-resistant infections already kill 700,000 people a year
Fortunately, the antibiotics currently available are sufficient to kill off the vast majority of infections. And, after a hiatus of some three decades, there is once again progress in the discovery of new classes of antibiotics1.
Meanwhile, there’s still enough variety of drugs that combination therapy should prove effective on even the most recalcitrant bugs for a while yet—giving time for new treatments to be refined and produced. One promising source of new antibiotics was fertile ground for previous discoveries too: soil.
Fungi and microbes that populate earth, including bacteria, have evolved toxins to keep other bacterial predators at bay—and these have the potential to become the antibiotics of the future.
Scientists recently discovered a compound called teixobactin, produced by a hitherto unknown soil-inhabiting bacterium. Teixobactin is highly effective against gram-positive bacteria, one of the main bacterial classifications. It also offers the additional benefit of not being toxic to mammalian cells.
Gram-positive bacteria include MRSA, an especially (pernicious and) intractable infectious agent that has been responsible for many hospital infections and subsequent deaths.
But gram-positive bacteria are generally more treatable. On the other hand, gram-negative bacteria have always been tougher to beat, thanks to their double cell walls — as opposed to gram-positive’s single membrane. The bacteria responsible for gonorrhoea is a particularly worrying gram-negative species. It develops resistance very rapidly and, for some strains, medics have nearly run out of effective drugs.
But researchers are working on using those double cell walls, which act as a protective shield against older types of antibiotics, as a means of defeating these bacteria. The walls have channels and gates that allow molecules to flow in and out. By developing compounds that would block these channels, scientists are hoping to find a way of killing the bacteria by essentially suffocating them.
A significant hurdle to discovering solutions directly in the soil is that only one in a million strains of microbe has any prospect of producing a useful antibiotic. Much better possibilities are offered by bacteria that have developed symbiotic relationships with fungi-farming ants. These bacteria, which live on the ants, feed off the fungi in exchange for producing chemicals to ward off enemy strains that could prove harmful to both ants and their harvests.2
Microscopic guided missiles
Another option is to revive an antibiotic therapy that largely predates penicillin-based drugs: the use of bacteriophages that target specific bacteria but leave human cells and other good microbes alone. Bacteria-killing viruses were used to treat infections from the 1920s, but their development lapsed once penicillin went into mass production.
Phage therapy, as it’s known, has remained in clinical use for some time in Russia and Georgia and, more recently, in Poland. It’s particularly useful because it is potentially a one-dose solution to infection—the bacteria-destroying phages will continue to multiply as long as their host is present. One of the problems of phage therapy, however, is that these viruses are highly specialised, potentially making very complex combination therapies necessary to treat some forms of infection.
The best way to deal with disease is to prevent it from happening in the first place
Of course, the best way to deal with disease is to prevent it from happening in the first place. Vaccination against certain bacterial infections that cause meningitis and pneumonia already exist. Larger vaccination programmes could cause the incidence of these infections to halve in small children.3 New vaccines could be targeted at other common infectious agents like strains of E. coli bacteria.
Innovation is unlikely to be a longterm solution unless people break the habit of generations: widespread over- and misuse of antibiotics.
This will be particularly difficult in developing countries. India in particular has seen rapid and widespread evolution of antibiotic resistance. Although Indians are far from the world’s biggest per-capita consumers of antibiotic drugs, they take more than people in most other emerging economies4. Poverty then becomes a major culprit. Poor social healthcare—which leads among other things to insufficient monitoring of the ill and to low immunisation rates—and patients’ frequent desire to save money by only taking enough medication to suppress symptoms rather than a full course helps bacteria to build up resistance.
There are, however, reasons to be hopeful here too. Policymakers are taking the problem increasingly seriously. All 193 member states signed a UN declaration to combat antibiotic resistance in September 2016. And doctors now know to be much more vigilant than they were in the past. Close monitoring of patients and heavily restricting use of last-line antibiotics will ensure bugs don’t survive a course of treatment—and thus can’t pass on resistance to future generations.
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Microbe-killing shards of silicon
As important as antibiotics are, it would be better to defeat bacteria before they have a chance to infect patients. It’s particularly crucial to stamp out microbes in hospitals and nursing homes, where the sick are often already reservoirs of infectious agents ready to take advantage of new hosts’ depressed immune systems.
Hospitals have been breeding grounds for resistant strains like MRSA. Better hygiene has helped, particularly closer monitoring of whether doctors are washing their hands between patients. But keeping bacteria from finding a home on work surfaces and medical instruments remains crucial.
One potential preventative solution is a by-product of solar cell research. Dr Paul Coxon, a material scientist at Cambridge University, discovered that the ultra-black silicon he’d developed to maximise its light retention capabilities was also a very good bactericide. On a nano scale, the silicon’s surface is like a jagged field of knives. Microbes settling on it are rapidly shredded before they have time to develop resistance. The thicker cell walls, which bacteria would need to evolve to survive in such a hostile environment would also tend to stop their necessary biological functions. Medical implements coated with a layer of this microscopically rough silicon could, in theory, reduce the risk of carrying deadly germs deep into patients undergoing surgery.
