Broad-range PCR/electrospray ionization time-of-flight mass spectrometry for the detection of bacteremia and fungemia in patients with neutropenic fever.
J Clin Microbiol. 2016 Jul 20;
Authors: Desmet S, Maertens J, Bueselinck K, Lagrou K
Infection is an important complication in patients with haematologic malignancies or solid tumours undergoing intensive cytotoxic chemotherapy. In only 20-30% of the febrile neutropenic episodes an infectious agent is detected by conventional cultures. In this prospective study, the performance of broad range PCR/electrospray ionization time-of-flight mass spectrometry (ESI-MS) technology was compared to conventional blood cultures (BC) in a consecutive series of high-risk hematology patients. In 74 patients, BC and a whole blood sample for PCR/ESI-MS (IRIDICA BAC BSI, Abbott, Carlsbad, USA) were collected at the start of each febrile neutropenic episode and, in case of persistent fever, also at day 5. During 100 different febrile episodes, 105 blood samples were collected and analyzed by PCR/ESI-MS. There was evidence of a bloodstream infection (BSI) in 36/105 cases (34%), based in 14 cases on both PCR/ESI-MS and BC positivity, in 17 cases on BC positivity only and in 5 cases on PCR/ESI-MS positivity only. Sensitivity of PCR/ESI-MS was 45%, specificity 93%, and the negative predictive value 80% compared to blood cultures. PCR/ESI-MS detected definite pathogens (Fusobacterium nucleatum, Streptococcus pneumoniae) missed by BC, whereas it missed both gram-negative and gram-positive organisms detected by BC. PCR/ESI-MS testing detected additional microorganisms, but showed a low sensitivity (45%) compared to BC in neutropenic patients. Our results indicate a lower concordance between BC and PCR/ESI-MS in the neutropenic population compared to what has been previously reported in other patient groups with normal white blood cell distribution and a lower sensitivity compared with other PCR-based methods.
PMID: 27440820 [PubMed - as supplied by publisher]