PCR/ESI-MS on Whole Blood Detects Bloodstream Pathogens in 25.6% of Sepsis Cases vs 14.6% by Culture
A 16-center study evaluated PCR/electrospray ionization-mass spectrometry on whole blood from 1,460 patients with suspected sepsis, comparing it with conventional blood culture. PCR/ESI-MS was positive in 25.6% of cases versus 14.6% for blood culture, with notably higher detection rates in patients receiving antimicrobial therapy (31% vs 22%). Specificities exceeded 94% for all individual species. The technology shows particular promise for culture-negative sepsis and patients already on antibiotics, though sensitivities varied by organism group.
The original study
Performance of PCR/Electrospray Ionization-Mass Spectrometry on Whole Blood for Detection of Bloodstream Microorganisms in Patients with Suspected Sepsis.
- Authors
- Strålin K, Rothman RE, Özenci V, Barkataki K, Brealey D, Dhiman N, et al.
- Journal
- Journal of clinical microbiology
- Type
- Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't
- PMID
- 32641399
Original abstract
Blood culture (BC) often fails to detect bloodstream microorganisms in sepsis. However, molecular diagnostics hold great potential. The molecular method PCR/electrospray ionization-mass spectrometry (PCR/ESI-MS) can detect DNA from hundreds of different microorganisms in whole blood. The aim of the present study was to evaluate the performance of this method in a multicenter study including 16 teaching hospitals in the United States (n = 13) and Europe (n = 3). First, on testing of 2,754 contrived whole blood samples, with or without spiked microorganisms, PCR/ESI-MS produced 99.1% true-positive and 97.2% true-negative results. Second, among 1,460 patients with suspected sepsis (sepsis-2 definition), BC and PCR/ESI-MS on whole blood were positive in 14.6% and 25.6% of cases, respectively, with the following result combinations: BC positive and PCR/ESI-MS negative, 4.3%; BC positive and PCR/ESI-MS positive, 10.3%; BC negative and PCR/ESI-MS positive, 15.3%; and BC negative and PCR/ESI-MS negative, 70.1%. Compared with BC, PCR/ESI-MS showed the following sensitivities (coagulase-negative staphylococci not included): Gram-positive bacteria, 58%; Gram-negative bacteria, 78%; and Candida species, 83%. The specificities were >94% for all individual species. Patients who had received prior antimicrobial medications (n = 603) had significantly higher PCR/ESI-MS positivity rates than patients without prior antimicrobial treatment-31% versus 22% (P < 0.0001)-with pronounced differences for Gram-negative bacteria and Candida species. In conclusion, PCR/ESI-MS showed excellent performance on contrived samples. On clinical samples, it showed high specificities, moderately high sensitivities for Gram-negative bacteria and Candida species, and elevated positivity rates during antimicrobial treatment. These promising results encourage further development of molecular diagnostics to be used with whole blood for detection of bloodstream microorganisms in sepsis.