The Evolution of Bacteria

In our battle to outwit bacteria are we fighting an impossible war?

Bacteria have been around for some 3 billion years and over that time nothing has adapted to its surroundings quite like it. Bacteria's ability to adapt and evolve creates interesting challenges for humans.

As bacteria increasingly develop resistance to antibiotics our medical system is under increasing pressure to develop new and more powerful antibiotics and vaccines, which, of course, will also help create new and more powerful bacteria.

This article from the BBC is worth reading.

“Sensible prescribing is part of the answer but we also need new antibiotics – it's not one of the most attractive areas for pharmaceutical companies as people don't take them for very long, unlike treatments for heart disease or cancer,” says Dr David Livermore, an infections expert at the Health Protection Agency.

“It is a war of attrition. There have been points where we have been advancing, and points when we have had to beat a retreat.

“If we were having this conversation 20 years ago for instance we would be celebrating the vaccine for bacterial meningitis. Really it is vaccines – rather than antibiotics – which hold the key to the big victories.”

In part is the ability to keep people alive for longer which has enabled some bugs to find a chink in our armour. The elderly and the sick, particularly those in hospital, have proved an attractive target for new strains.

Clostridium difficile is a bacteria which particularly hits elderly people who have already been treated with antibiotics, treatment which has killed off the “good” bacteria that protects the intestines.

Indeed relatively few bacteria cause disease. For the most part the ones that live within us are doing helpful tasks such as consuming dead skin, or even producing vitamins in the gut.

It is a give and take relationship – the same cannot be said for viruses such as swine flu.

A virus has no cell of its own and so needs to enter a living organism, usually via the skin or internal surfaces such as gut, respiratory system or genitourinary tracts.

Once inside they quickly reproduce, and are well-located to make a quick exit to the outside world. In the case of swine flu we sneeze into our hand before shaking another's, and the virus is effectively spread.

Influenza is seen as the most wily of viruses, constantly adapting to thwart our attempts to combat it.

But experts stress the globalisation which makes foreign infectious diseases no more than a plane ride away is also the key to controlling and even curing them – bringing for instance the best scientific minds together, and securing the supply of drugs.

“We have to keep this particular virus in perspective – it so far appears to be mild and self-limiting,” says Dr Primrose Freestone, lecturer in clinical microbiology at the University of Leicester.

“But more generally I think we can be upbeat. We will always be at war with microbes. Their genetic promiscuity is impressive, but we are learning more about them all the time. They are versatile and enduring – but so are we.”

Full Article.