Routine use of a real-time polymerase chain reaction method for detection of bloodstream infections in neutropaenic patients ☆ , ☆☆ Michela Paolucci a , Marta Stanzani b , Fraia Melchionda c , Giulia Tolomelli b , Gastone Castellani d , Maria Paola Landini a , Stefania Varani a , Russell E. Lewis e , Vittorio Sambri a, ⁎ a Unit of Microbiology, Department of Specialistic, Diagnostic and Experimental Medicine, University of Bologna, 40138 Bologna, Italy b Institute of Hematology “Lorenzo e Ariosto Seràgnoli” Sant'Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy c Paediatric Oncology and Hematology Unit “Lalla” Seràgnoli, University of Bologna, 40138 Bologna, Italy d Physics Department, Bologna University, 40127 Bologna, Italy e Texas Medical Center, University of Houston College of Pharmacy, Houston, TX 77030, USA abstract article info Article history: Received 24 July 2012 Received in revised form 2 October 2012 Accepted 14 October 2012 Available online 22 November 2012 Keywords: Bloodstream infection Neutropaenia Blood culture PCR Haematologic cancer patient Antibiotic therapy We examined the performance of a real-time polymerase chain reaction (PCR) test (SeptiFast) for early detection of bloodstream infection in febrile neutropaenic patients. Blood samples from 201 patients were screened for pathogens by blood culture and by PCR on the first day of fever. PCR results were available earlier (median 3 days for bacteria, 5 days fungal pathogens; P ≤ 0.01). The sensitivity (0.74) and specificity (0.96) of the PCR test were acceptable for Gram negatives when culture was considered the gold standard, but sensitivity of the test was poorer for Gram-positive organisms (0.39). The PCR assay also led to 22.9% of invalid results. SeptiFast speeds the microbiological diagnosis of bloodstream infection in neutropaenic patients. However, the frequent failure of instrumental control procedures, the relatively poor sensitivity of the test, and the lack of phenotypic data on antimicrobial susceptibility associated with its high costs suggest that this assay cannot replace the blood cultures. © 2013 Elsevier Inc. All rights reserved. 1. Introduction Neutropaenia is a major risk factor for bloodstream infections (BSIs) in patients with haematological cancer. Fever develops in 65% of cancer patients receiving fluoroquinolone prophylaxis during the neutropaenic period, but a microbiologically documented diagnosis is made in only 22% of these cases (bacteraemia 18%) (Bucaneve et al., 2005). Bloodstream infections are routinely diagnosed with blood cultures taken at the onset of fever (Hughes, 2005; Penack et al., 2006). However, one disadvantage of this method is the turn- around time of 2–6 days before the results are available (Bucaneve et al., 2005). Additionally, the sensitivity of blood culture is reduced in neutropaenic patients with haematologic malignancies because they often receive prophylactic antibiotics and are at risk for infec- tions caused by cell-wall deficient bacteria and filamentous fungi, which are rarely detected by blood culture (Carrigan et al., 2004; Woo et al., 2001). The detection of microbial DNA in blood by polymerase chain reaction (PCR) is a promising approach for diagnosing BSIs (Mancini et al., 2008). A common limitation in the assessment of novel molecular methods is the absence of a gold standard for detection of BSIs. In neutropaenic cancer patients in particular, the interpretation of PCR results is limited by negative blood culture results due to antibiotic treatment (Peters et al., 2004). Consequently, some authors have recommended that positive PCR results for blood culture–negative febrile episodes be interpreted based on corresponding clinical features of the infection rather than on purely microbiological results (Nakamura et al., 2010; Peters et al., 2004). Previously, we assessed the clinical utility of a commercially available multiplex real-time PCR assay (LightCycler SeptiFast Test M GRADE ; Roche Diagnostics, Mannheim, Germany) for the microbio- logical diagnosis of BSIs in 100 severely immunocompromised patients (Varani et al., 2009). Since then, we have routinely used this procedure along with standard blood culture, evaluating in total 201 neutropaenic patients over the past 2 years. Based on this experience and on our analysis, we have identified advantages and limitations of this technology for diagnosis of infections in neutro- paenic patients. Diagnostic Microbiology and Infectious Disease 75 (2013) 130–134 ☆ Funding: This work was supported by RFO 2009-2010 from the University of Bologna (to VS, MPL and SV); the Italian Ministry of Education, University, and Research MIUR (PRIN 2007, MPL, VS, SV, GC). ☆☆ Transparency declarations: none to declare. ⁎ Corresponding author. Tel.: +39-051-6363013. E-mail address: vittorio.sambri@unibo.it (V. Sambri). 0732-8893/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.diagmicrobio.2012.10.012 Contents lists available at SciVerse ScienceDirect Diagnostic Microbiology and Infectious Disease journal homepage: www.elsevier.com/locate/diagmicrobio