Wednesday, 27 July 2016

Resistance is futile: the ongoing war against super bugs

As I'm currently three days into an irritating cough (aren't they all?) accompanied by a sore throat, I've just taken a soothing lozenge. The packet states the lozenges contain a combination of two antibacterial agents which aim to help kill the bacteria causing the infection. However, the packet also notes - in a somewhat smaller font size - that there is no clinical proof an antibacterial agent will reduce the severity or duration of the infection. Could this be because common colds and influenza are caused by viruses not bacteria? I don't suppose the pharmaceutical industry could possibly be duping an ignorant public in the name of profit margins?

Working in a hot desking environment, I frequently remind colleagues not to overdue usage of anti-bacterial sprays on their desk, keyboards, mouse and telephone. Not that I'm exactly certain how damaging the company-supplied sprays are, environmentally-speaking: for all I know, they may be good enough to destroy all the 'bad' bacteria, but I'd rather be safe than sorry. Instead, I recommend the method I use at work, namely washing my hands before eating. Simple, and hopefully less likely to encourage super bugs.

It seems to me that basic hygiene is preferable to the chemical war on microbes, since (a) some are beneficial, including for building immunity; and (b) some strains may survive the cull and lead to a desk biota high in resistant bacteria: after all, isn't that just Darwinian natural selection being given an unintentional boost? Unfortunately, there has been a large increase in sick leave since we moved from conventional offices to hot-desking. Therefore something is clearly going wrong, regardless of approach!

The best well-known of the super bugs has to be Methicillin-resistant Staphylococcus aureus (MRSA), beloved of news journalists but very few others. Although the resistance was first recognised around 1960, the past twenty-five years or so has seen a plethora of scientific reports describing outbreaks separated from healthcare environments. Therefore popular news articles about super bugs in hospitals - and the over-use of antibiotics that have aided their increase in range - only started hitting the headlines after the bacteria had already spread to other types of locale.

This latter community-associated or CA-MRSA is therefore at least as great a risk as the hospital variant, often affecting younger people. MRSA naturally occurs in several percent of the population anyway, so it would be difficult to totally eradicate by any foreseeable method. Many common antibiotics are already useless against MRSA, which can be spread by direct skin contact as well as via objects - such as computer keyboards and mice I might add, to anyone considering converting their offices to hot desking. In addition, the far less well-known methicillin-sensitive Staphylococcus aureus (MSSA) is also on the increase.

Another key reason for the increase of resistant microbes is thanks to the use of antibiotics on farmed animals. Whilst it might seem sensible for densely-packed livestock to be inoculated - frankly I don't mind paying more for free range rather than battery-farmed eggs, but I realise that isn't an option for many - the discovery in the 1940s that antibiotics can be used to promote growth imply profit is yet again the key factor here. Far from being a simple precautionary measure against the spread of infection, livestock and poultry has been given pharmaceuticals in order to maximise produce without an associated increase in feeding costs.

In 1969 the Swann report on the Use of Antibiotics in Animal Husbandry and Veterinary Medicine recommended a cease on their use as growth promoters. After a long period of inertia, the European Union eventually banned such usage for eight antibiotics, four in 1989 and a further four in 2006. Unfortunately many other nations, including the USA, are still pumping enormous amounts of pharmaceuticals into farm animals.

I've found very little in the way of research projects that seek to lessen this dependency. Possibly the method containing the least disruption would be to develop drugs that have similar effects on animal growth but aren't required as human medicine. Perhaps the pharmaceutical giants just aren't finding antibiotic development profitable enough anymore; after all, if medical practice wants to prevent the spread of resistant bacteria it needs to minimise use of antibiotics.

The effects agricultural usage is having is wide-ranging, from pathogens crossing from livestock to humans and back again, to infections spreading to pets and even into wild animals such as flies and rodents. However, the USA seems to have made little effort to follow the EU, with about 80% of the antibiotics sold there being used on farm livestock. Yet another MRSA variant, CC398, has been gaining ground, particularly in pigs and can transfer to humans in the form LA-MRSA. What price a cheap bacon sandwich?

It isn't as if the American scientific establishment hasn't been amassing data to support the case for stopping the practice, which over the past half century or so has led to other, less well-known strains such as Campylobacter coli gaining immunity, Despite high levels of infected produce, large-scale recalls and perhaps over 100,000 deaths per annum in the USA alone (farm workers and food processors can pick up strains, not just the end consumer), commerce appears to be winning over common sense.

It isn't completely bad news: research by the University of Southampton indicates that copper might become useable as an inhibitor (which seems strange - I thought silver might be the metal of choice, considering its anti-bacterial properties - guess that proves I'm not a research chemist, then!) In addition, some of the main fast food chains have started to cut down on buying produce from antibiotic-pumped livestock. But is this too little much too late? With most pharmaceutical production in the hands of a few giant multi-nationals, the human race is largely beholden to a very small number of executives. My suggestion would be...err...just don't get ill? Or work in a hot desking environment. Or leave your home, ever...hmm...