How do I identify pathologic organisms in the 21st century

Abstract: Classical diagnostics in infectious disease have relied on cultures for pathogen identification for over a century. When a causative pathogen is cultured and antimicrobial susceptibility tests are performed, the physician can change any empirically started antibiotics into directed therapy. While antibiotics are life-saving in critically ill patients with sepsis, we are increasingly aware of the potential harmful side effects of empiric antibiotic treatment and are confronted with the threat of widespread antimicrobial resistance. Therefore, it is essential not only to identify the causative pathogen within a few hours but also to acquire rapid information on antimicrobial susceptibility. Emerging technologies for molecular diagnostics led to the development of rapid diagnostic tests including hybridization, nucleic acid amplification and post-amplification methods, and more novel techniques based on nuclear magnetic resonance techniques. The ideal yet to be developed test should be performed on easily available samples (such as blood or urine) and be applicable to a low volume (to be of use in neonatal care also). It should combine its results with information regarding the immune status of the host, potentially obtained from the same all-inclusive bedside test. It is of upmost importance to evaluate the incorporation of the novel test in every day clinical care and to study its effects on long-term patient related outcomes. These early-21st century diagnostics form the beginning of a century with potential to develop ultra-rapid tests to steer targeted therapy for pathogen elimination and patient-based immunomodulatory support.