The Utility of Rapid Microbiological and Molecular Techniques in Optimizing Antimicrobial Therapy

Early treatment of bloodstream infections with appropriate, definitive antimicrobial therapy has proven to reduce mortality, length of hospital stay, and healthcare costs. Culture-based testing methods require up to five days for final pathogen identification and susceptibility reporting, forcing use of broad spectrum empiric therapy. Recently, multiple rapid microbiological and molecular testing methods have been developed that reduce the time to identify the pathogen and susceptibility, allowing optimal antimicrobial therapy to be prescribed earlier. Real-time polymerase chain reaction and gene microarray have been described in literature, yet only peptide nucleic acid fluorescent in-situ hybridization has published data justifying its use based on clinical outcomes and cost savings. Target enriched multiplex polymerase chain reaction was developed to identify both the pathogen and multiple genes associated with resistance from blood within 6 hours and this methodology was studied in our hospital to assess effectiveness at optimizing antimicrobials in staphylococcal bloodstream infections.