Potential Clinical Usefulness of the Polymerase Chain Reaction Test to Detect Pathogens Causing Sepsis

Abstract

Objective: A real-time polymerase chain reaction (PCR) test is expected for early and precise detection of pathogens in blood. In this study, we compared the ability of the PCR test and blood culture to detect pathogens in the blood of patients with sepsis. Methods:Patients who were diagnosed as or suspected of having sepsis were included in this prospective observational study. A whole blood sample for PCR test was obtained serially simultaneously with the blood culture sample, and the results were compared. Results:We obtained 93 samples from 26 patients; 69 samples were obtained during the septic condition, and 24 samples were from the non-septic condition. Origins of sepsis were pneumonia in 9 patients, necrotizing fasciitis in 5 patients, and other causes in 12 patients. In the septic condition, rates of positive results were 29.0% for the PCR test and 23.2% for blood culture. Sample contamination occurred in 1 PCR test sample and 5 blood culture samples. In positive PCR samples, 16 of 20 samples were obtained during sepsis after beginning administration of broadspectrum antibiotics, whereas 5 of 12 samples, except for contaminated samples, were positive in blood culture. Conclusion:In sepsis, the PCR test detected more bacteria than did blood culture even after administration of empirical antibiotics, which might contribute to precise diagnosis of the bacteremic cause of sepsis.