Rapid microbial identification and antimicrobial susceptibility testing to drive better patient care: an evolving scenario

Antimicrobial chemotherapy for septic patients begins with empirical therapy and can be subsequently revised when the results of microbiological testing become available. In recent years, a number of novel technologies for the microbiological diagnosis of sepsis have been developed that return results in a shorter timeframe compared with conventional diagnostic approaches. These novel technologies aid antimicrobial stewardship when treating septic patients by reducing the time to appropriate antimicrobial chemotherapy. Advantages and limitations of these technologies should be well understood upon their introduction in the diagnostic workflow. Increasingly popular DNA-based technologies primarily focus on the rapid identification of pathogens, but information on antimicrobial susceptibility is lacking or limited to a few clinically relevant resistance markers. Thus, DNA-based molecular techniques can complement conventional technologies but cannot replace them. On the other hand, a novel technology that provides both rapid identification of bacterial pathogens and a rapid phenotypic antibiogram with MIC values, and which starts from positive blood cultures, is a very promising approach for fast diagnosis of sepsis. To fully leverage the advantages offered by novel diagnostic technologies for sepsis requires a careful introduction into the laboratory workflow, following an evaluation by a health technology assessment approach. It may also require some reshaping of the workflow (e.g. to process the positive blood cultures on a 24/7 schedule) and of the laboratory organization (e.g. by creating a laboratory subsection for fast diagnosis of sepsis).