| Introduction. Sepsis is a severe systemic inflammatory response to infection and is associated with high mortality. Blood culture (BC) serves as the clinically accepted pathogen detection method for septicemia. It is recommended that BC's are collected before initiating antimicrobial therapy to avoid false negative results, but this may be unsafe in high-risk patient groups. Therefore, different pathogen detection modalities are needed. Nucleic acid amplification testing (NAAT) may serve as a potential adjunct to cultures under these circumstances.;Experimental design. This study focuses on discovering the clinical advantages of NAAT. A multiplex PCR-based pathogen detection system was used in trauma surgery and burn surgery patients. Fifty patients were tested by PCR, and results compared to BC. Serial PCR testing was used to determine the presence of pathogen DNA during antimicrobial therapy. Non-blood cultures were also compared to PCR results. Based on NAAT results, clinical referees identified the clinical significance of discrepant results and adequacy of antimicrobial therapy.;Results. Twenty four (48%) patient samples were PCR+. Eight were PCR+/BC+ for the same pathogen. Discrepant values included: 12 PCR+/BC- (single pathogen), 4 PCR+/BC- (multi-pathogens), 2 PCR-/BC+ (single pathogen), 2 PCR-IBC+ (multi-pathogens), and 2 PCR-/BC+ for a pathogen not found on our test. Paired wound culture's agreed more frequently with PCR. PCR detected clinically significant pathogens such as Enterobacter species, Klebsiella species, and Staphylococcus aureus earlier than BC. Serial PCR samples were PCR+IBC- for patients with existing antimicrobials therapy. Antimicrobial therapy was adequate only 58% of the time.;Conclusions. PCR rapidly detected more pathogens and often times detected pathogens which BC missed. Successive serial PCR results were frequently positive versus negative BC's; possibly due to inhibition by antimicrobial therapy. Some PCR+/BC- results were coupled to positive non-BC's. This may indicate PCR's potential to detect early pathogen invasion from non-hematologous sources and/or its ability to detect bloodstream infections that are not detectable by BC. PCR+/BC- results could suggest bacteremia and/or DNAemia during antimicrobial therapy. Therefore, PCR may have value in discovering microbial colonization, seeding, infection, or destroyed pathogens during treatment for guiding antimicrobial therapy. |
