Multiplex PCR To Diagnose Bloodstream Infections in Patients Admitted from the Emergency Department with Sepsis

Abstract

Sepsis is caused by a heterogeneous group of infectious etiologies. Early diagnosis and the provision of appropriate antimicrobial therapy correlate with positive clinical outcomes. Current microbiological techniques are limited in their diagnostic capacities and timeliness. Multiplex PCR has the potential to rapidly identify bloodstream infections and fill this diagnostic gap. We identified patients from two large academic hospital emergency departments with suspected sepsis. The results of a multiplex PCR that could detect 25 bacterial and fungal pathogens were compared to those of blood culture. The results were analyzed with respect to the likelihood of infection, sepsis severity, the site of infection, and the effect of prior antibiotic therapy. We enrolled 306 subjects with suspected sepsis. Of these, 43 were later determined not to have infectious etiologies. Of the remaining 263 subjects, 70% had sepsis, 16% had severe sepsis, and 14% had septic shock. The majority had a definite infection (41.5%) or a probable infection (30.7%). Blood culture and PCR performed similarly with samples from patients with clinically defined infections (areas under the receiver operating characteristic curves, 0.64 and 0.60, respectively). However, blood culture identified more cases of septicemia than PCR among patients with an identified infectious etiology (66 and 46, respectively; P ‫؍‬ 0.0004). The two tests performed similarly when the results were stratified by sepsis severity or infection site. Blood culture tended to detect infections more frequently among patients who had previously received antibiotics (P ‫؍‬ 0.06). Conversely, PCR identified an additional 24 organisms that blood culture failed to detect. Real-time multiplex PCR has the potential to serve as an adjunct to conventional blood culture, adding diagnostic yield and shortening the time to pathogen identification.

Diagnostic performance and therapeutic impact of LightCycler SeptiFast assay in patients with suspected sepsis

“…Our study showed good concordance rate between SF and BC results, which is comparable with other studies [10,14,17,18]. The majority of non-concordant results consisted of SF positive but BC negative results.…”

“…In this regard, Tsalik et al recently determined in a cohort of patients presenting in emergency rooms that the presence of DNA in blood as detected by SF is indeed an indicator of infection [14].…”

“…It is a relatively rapid molecular method allowing detection of sepsis pathogens in approximately 6 h. There are several studies to date about diagnostic feasibility and potential clinical utility of SF [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Fewer studies have evaluated this assay in routine clinical practice regarding impact on therapy [25,26].…”

“…The assay can be performed in less than 6 h and it identifi es 25 most important pathogens causing bloodstream infections (Table 2). A number of studies have evaluated the SeptiFast assay in different patient populations [13][14][15][16]. However, few studies have addressed the clinical impact of the use of SeptiFast.…”

Comparison of three different commercial PCR assays for the detection of pathogens in critically ill sepsis patients

“…These results stand in contrast to the results of our study, where the blood cultures showed a higher pathogen detection rate. Other recent research is in line with our results: studies investigating patients with suspected sepsis in the emergency department [21], patients with malignancies and sepsis [22], critically ill neutropenia patients [23] and etiological diag- nosis of community-onset bloodstream infections [24]. The other two PCR assays (SepsiTest® and VYOO®) are less well studied in respect to sepsis.…”