Good health is a key factor of our life and we live with an increasing life expectancy. Despite technological and medical progression, life threatening infections are returning as a serious threat even in well developed countries like Denmark and the societal costs of infectious diseases are considerable. Over the next decades our society will go through changes that greatly affect our sensitivity to microbial pathogens where the most pronounced will be the increase in elderly, immuno-compromised and hospitalized people. Such citizens are susceptible to chronic infections caused by well known bacteria such as Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. In Denmark, ~100.000 hospitalized patients acquire infections, often in connection with the use of medical devises such as arteriovenous shunts, pacemakers, urinary and other types of catheters, orthopedic devices and mechanical heart valves with an estimated 200-300 annual fatalities. Skin ulcers that develop into chronic wounds are also a significant and partly neglected problem, which affects patients with impaired blood circulation in particular diabetes patients. It is assumed that ~ 50.000 patients suffer from wounds that require special treatment and medical attention because of bacterial infections. This is an important socioeconomic burden, which includes patient suffering, lost employment and reduced life quality. The problem is growing in pace with the increasing emergence of multidrug-resistant bacteria.