Bakteriel biofilm og antibiotisk resistens

Some 50 years ago, in the golden age of antibiotic discovery, bacterial infections were predominantly acute. However, major societal changes such as aging populations, growing hospitalization rates, and the use of medical devices as essential components of modern-day medical treatment, increasingly expose citizens to chronic infections. Chronic infections are often caused by bacteria in the form of biofilms. This contrasts with acute infections that typically involve bacteria in a free-living (planktonic) form. Chronic infections are usually associated with modern medical procedures, e.g. artificial hips, knees, heart valves, stents, catheters, vascular prostheses, pacemakers, etc., and with distinct disease states such as non-healing wounds, COPD, cystic fibrosis, and urinary tract infections. Traditionally, physicians have focused on diagnosing and fighting the infecting pathogen with a combination of classic cultivation methods and subsequent selection of a single antibiotic treatment; an approach now rendered ineffective by the emerging chronic infections, rapid development and spread of new resistance mechanisms and a lack of novel antibiotic discoveries. A major shortcoming of previous antibiotic discovery is that it aimed at growth inhibition of bacteria present in an unshielded state. However, biofilms predominantly consist of shielded cells in a non-growing state. Furthermore, when new resistance mechanisms emerge, they spread readily by cell-to-cell contact in densely packed biofilms. Since actively growing and unshielded planktonic bacteria are easier to kill, our strategy localizes the biofilm infection, dismantles the biofilm, and kills the liberated bacteria.