Monday, 21 September 2020

Viruses to the Rescue?

Antibiotics are chemicals (often produced by natural organisms- like the first one, Penicillin) that can attack a spectrum of bacteria (the natural ones facilitate the producer's ability to compete with bacteria for 'substrate'i.e. food). Antibiotics transformed the medical treatment of infections, that formerly resulted in amputation and/or death. These agents, however, are very expensive, as well as time-consuming, to develop and have been massively overused. Sometimes, they are given at the patient's insistence for a viral infection (they don't work on viruses, such as the causal agent of influenza). Doctors have also been known to prescribe them as a 'test' to see if the infection is viral. They are also much used by farmers as growth enhancers for animals (thus increasing their profits). The trouble is that wherever an antibiotic is employed, it exerts a powerful selection pressure on the rapidly-reproducing (about every 20 minutes) bacteria. The only bacteria that breed in the next generation, after treatment, are those that survived the antibiotic. This gives rise to the so-called 'superbugs' (more properly labelled 'antibiotic resistent bacteria'). These strains of bacteria (commonly found in some hospitals and care homes, where antibiotics are commonly and repeatedly utilised), can cause infections that are resistant to any of the currently available antibiotics. These 'untreatable infections' can lead to the deaths of the patients (the World Health Organisation estimates that, without alternative treatments being developed, by 2050 more than 10 million people, infected with a superbug, will die each year). Some people are advocating a return to the use of bacteriophages to treat bacterial infections ( https://www.theguardian.com/global-development/2020/sep/21/phages-the-tiny-viruses-that-could-help-beat-superbugs ). Bacteriophages are tiny viruses that are sometimes described as 'predators' (I would argue that 'parasites') of bacteria. Each phage is only effective against a limited number of bacterial species (in the same way that parasites have a limited range of hosts). Phages are, however, much cheaper and quicker to develop than an antibiotic (they can be formulated in nations with less developed medical/pharmaceutical systems). They also don't appear to have any side-effects on patients. It seems that phages could become an effective alternative treatment for people infected with a superbug strain (such as Methicillin Resistant Staphylococcus aureus).

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Seeing the Changes 2104

Funnel fungi ( Clitocybe spp) at Bynea.