„It is time to close the book on infectious diseases, and declare the war against pestilence won“. Today we know that this statement, most likely incorrectly attributed to a previous US Surgeon General, is anything but true. More than ever, the medical community is in search of new antibiotics because their excessive use – also in veterinary medicine and as growth promotor – has resulted in widespread antibiotic resistance in bacteria that cause severe infections. The normal way used up to now to modify existing substances has become more and more difficult and, therefore, new strategies are desperately needed.
A largely unexploited source for new compounds is the environment where abundant bacteria produce numerous substances as defense against each other. However, as up to 99% of these organisms are uncultured in vitro, a new device (iChip, see picture) for culturing these bacteria in their natural environment has received wide attention. A sample of soil is diluted to an extent that, after loading the iChip, each of the numerous channels contains approximately one single bacterial cell. The iChips are then covered with semi-permeable membranes allowing for diffusion of nutrients and growth factors, and placed back in the soil. Once colonies are produced by this procedure, a considerable fraction of previously uncultured isolates is able to grow in vitro and can then be screened for antimicrobial activity. One of the newly detected substances is Teixobactin with activity against critical bacteria by a mechanism against which resistance is expected to develop very slowly – if at all.
Prof. Dr Martin Altwegg, Scientific Board Member