Antibiotic resistance (AR) is a worldwide problem which, according to many, is reaching crisis proportions. A recent government report stated that there are 'few public health issues of greater importance than antimicrobial resistance in terms of impact on society. This problem is not restricted to the UK. It concerns the entire world and requires action at local, national and global level'.1
Since their introduction in the 1940s, antibiotics have saved millions of lives worldwide by curing bacterial infections that had previously often proved fatal. However, soon after their earliest trials it became evident that some bacteria were naturally resistant to these agents. Even Alexander Fleming stated, 'The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant'.2
Throughout their evolution bacteria have adapted to substances in their environment that could be harmful, leading to changes in their genetic makeup and internal chemistry to avoid these potentially fatal substances. However, human pathogenic bacteria have been under increasing selective pressures from synthetic antimicrobial substances to which they are repeatedly exposed, often at sublethal concentrations, allowing them to become resistant and continue to thrive.