Antibiotics in an anti-science age

This is another repost originally written for the old blog in 2007.

Over the next few years or decades, traditional antibiotics will largely be replaced by bacteriophages. Like everything in biology and medicine, this is ultimately down to evolution. Pathogenic bacteria are alive: they reproduce, with slight imperfections, and are therefore subject to selection. Because antibiotics are a potentially fatal environmental variable, they make an incredibly strong selection pressure. Some individuals within a population of bacteria will, by chance, have some ability to break down or pump out the antibiotic. Some of those might be lucky enough to survive the first dose of the antibiotic, and will then proliferate, generating new variations, and the process repeats with the next dose. Bacteria have another powerful weapon against antibiotics: horizontal gene transfer. Individual bacteria, not only within a species, but also of the most distantly related species, can come together and swap useful genes, such as those that break down or pump out harmful foreign chemicals. Antibiotics have only been widely used in the past century, during which time we have discovered a hand full of antibiotic classes. Some of these work on many or most types of bacteria (broad spectrum), but most are limited in their targets. As bacteria evolve resistance to one antibiotic, the drug companies provide an alternative: a slight variation on the theme. But because the replacement antibiotics are so similar to those for which the bacteria already have resistance, they do not last very long before they too succumb. Hence we have dozens of *cillin antibiotics, most of which are consigned to history.

Phages are viruses which take over bacteria, commandeer their systems of DNA replication and gene expression in order to replicate, and eventually destroy them. Because phages are themselves imperfect replicators, they too can evolve. Phage reproduction involves such huge copy numbers that the phages can generate more variation than their hosts, and therefore evolve quicker and always win the evolutionary arms war with them. Chemical and phage based antibiotics were conceived of and first developed at around the same time, and both were successfully put into use, but for whatever reason, the chemicals won the battle and the phages were largely forgotten. At least, that’s the story in the west. The former Soviet countries continued to use phages; millions of people were successfully and safely treated with them, and a lot of research was done. So, widespread use of phages as an antibiotic in western medicine does not need to be a distant prospect. Pharmaceutical, biotech, and public labs have several products ready, in various stages of approval for use. As the antibiotic resistance problem reaches crisis and becomes an ever greater political issue, the will and money to advance the use of phages grows.

But we must not be complacent. At present, the issue has not been widely picked up by the mainstream media, but it has the potential to be a story of great interest to them. We are living in an era where scientific advances are under assault from a diverse range of parties, for reasons that are often so bizarre as to catch scientists by surprise. Never underestimate the ability of newspapers, consumers, and vested interests to create doubt and controversy where none should exist. And phages have a whole menu of issues to get the journalists salivating. There is the obvious fact that these are viruses, of which the public are only acquainted with the nastiest varieties. There is the potential factor of genetic engineering, which in the UK has the somewhat surreal public image of being all about creating Gothic monsters from vegetables (whether this is expected to be by accident or done deliberately is not always clear). And then there’s the fact that these were developed by communists, who no doubt “used them on their own people”! The Americans will have to add evolution to the equation. But then, while phages may be viruses, at least they’re natural, rather than chemicals — modern synonyms for “good” and “bad” respectively. And we also have the issue of multi-drug resistant diseases — notably MRSA, C. difficile, and increasingly, Tuberculosis — which are favourite topics of the media. At the moment, from the point of view of a tabloid hack, this story has the appearance of a cat with buttered toast strapped to its back. So, lets get the scientific word in first, before anybody can turn this into another genetic engineering or stem cell research story.

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