SeptiFast real-time PCR for detection of bloodborne pathogens in patients with severe sepsis or septic shock.

ABSTRACT

Several studies have been performed investigating the role of a real-time multiplex polymerase chain reaction assay LightCycler SeptiFast with inconsistent results. In prospective evaluation of adult patients with severe sepsis or septic shock SeptiFast assay and blood culture results were compared regarding concordance, the impact of SeptiFast assay on antimicrobial therapy adjustment, time to results and the role of SeptiFast assay as a marker of disease severity. 63 blood sample sets were collected from 57 patients. 51 (80.9%) results were concordant negative and 7 (11.1%) concordant posi- tive. In one (1.6%) sample set blood culture was positive and SeptiFast assay negative, in three (4.8%) sample sets with negative blood cultures pathogens were detected by SeptiFast assay and in one (1.6%)patient an additional pathogen was detected by SeptiFast assay. If blood culture is considered as "gold standard", 1 (1.6%) SeptiFast false negative and 4 (6.3%) false positive results were identified (sensitivity 87.5%, specificity 92.6%, negative predictive value 97.8%). Antibiotic treatment was adjusted according to SeptiFast assay in 4 (6.3%) cases. Time to final results was significantly shorter with SeptiFast assay (32 +/- 23 h vs. 97 +/- 28 h, p < 0.0001). Positive SeptiFast assay was not associated with higher mortality, C-reactive protein orprocalcitonin (p = 0.74, p = 0.44 and p = 0.12, respectively). According to our results SeptiFast assay can be used as a valuable add-on to blood culture in diagnostic workup ofpatients with severe sepsis and septic shock but it cannot replace the blood culture.