There has been a general over-prescription and misuse of antibiotics which has led to antibiotic resistance and the rise of ‘super bugs’ like C difficile and MRSA.

Too many visits to the doctor end with a prescription for an antibiotic. That may be perfectly valid for a severe bacterial infection, but coughs and colds, for example, are usually caused by viruses, which cannot be treated with antibiotics. Nevertheless, nearly a half of children with common colds are treated with antibiotics.

Inappropriate use of antibiotics is an ultimately self-defeating activity, as antibiotic use inevitably induces antibiotic resistance – an example of natural selection in action.

Inevitable resistance

Bacteria have a shorter life cycle than ours, and DNA that is somewhat less stable, so they continually and rapidly produce variants on a genetic theme.

So if an antibiotic is given improperly (for example at too low a dose, or too infrequently) or the course is not finished by the patient, those bacteria which were slightly more resistant to the antibiotic survive in larger numbers.

Among their descendants, those with the strongest resistance survive preferentially; and within a surprisingly short period of time, full-blown resistance can emerge.

Leading bacteriologists now believe that the world may run out of effective antibiotics by 2010, with a gap of five years or more before new drugs can be developed.

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