title: Clinical Impact of MALDI-TOF MS Identification and Rapid Susceptibility Testing on Adequate Antimicrobial Treatment in Sepsis with Positive Blood Cultures.
abstract: Shortening the turn-around time (TAT) of positive blood culture (BC) identification (ID) and susceptibility results is essential to optimize antimicrobial treatment in patients with sepsis. We aimed to evaluate the impact on antimicrobial prescription of a modified workflow of positive BCs providing ID and partial susceptibility results for Enterobacteriaceae (EB), Pseudomonas aeruginosa and Staphylococcus aureus on the day of BC positivity detection. This study was divided into a pre-intervention period (P0) with a standard BC workflow followed by 2 intervention periods (P1, P2) with an identical modified workflow. ID was performed with MALDI-TOF MS from blood, on early or on overnight subcultures. According to ID results, rapid phenotypic assays were realized to detect third generation cephalosporin resistant EB/P. aeruginosa or methicillin resistant S. aureus. Results were transmitted to the antimicrobial stewardship team for patient's treatment revision. Times to ID, to susceptibility results and to optimal antimicrobial treatment (OAT) were compared across the three study periods. Overall, 134, 112 and 154 positive BC episodes in P0, P1 and P2 respectively were included in the analysis. Mean time to ID (28.3 hours in P0) was reduced by 65.3% in P1 (10.2 hours) and 61.8% in P2 (10.8 hours). Mean time to complete susceptibility results was reduced by 27.5% in P1 and 27% in P2, with results obtained after 32.4 and 32.6 hours compared to 44.7 hours in P0. Rapid tests allowed partial susceptibility results to be obtained after a mean time of 11.8 hours in P1 and 11.7 hours in P2. Mean time to OAT was decreased to 21.6 hours in P1 and to 17.9 hours in P2 compared to 36.1 hours in P0. Reducing TAT of positive BC with MALDI-TOF MS ID and rapid susceptibility testing accelerated prescription of targeted antimicrobial treatment thereby potentially improving the patients' clinical outcome.
authors.affiliation: Institut de recherche expérimentale et clinique (IREC), pôle de microbiologie (MBLG), Université catholique de Louvain, Brussels, Belgium.|Laboratoire de microbiologie, Cliniques universitaires Saint-Luc - Université catholique de Louvain, Brussels, Belgium.
authors.forename: Alexia
authors.initials: A
authors.lastname: Verroken
authors.affiliation: Laboratoire de microbiologie, Cliniques universitaires Saint-Luc - Université catholique de Louvain, Brussels, Belgium.
authors.forename: Lydwine
authors.initials: L
authors.lastname: Defourny
authors.affiliation: Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Olivier
authors.initials: O
authors.lastname: le Polain de Waroux
authors.affiliation: Département de médecine interne et pathologies infectieuses, Cliniques universitaires Saint-Luc - Université catholique de Louvain, Brussels, Belgium.
authors.forename: Leïla
authors.initials: L
authors.lastname: Belkhir
authors.affiliation: Département des soins intensifs, Cliniques universitaires Saint-Luc - Université catholique de Louvain, Brussels, Belgium.
authors.forename: Pierre-François
authors.initials: PF
authors.lastname: Laterre
authors.affiliation: Institut de recherche expérimentale et clinique (IREC), pôle de microbiologie (MBLG), Université catholique de Louvain, Brussels, Belgium.|Laboratoire de microbiologie, Cliniques universitaires Saint-Luc - Université catholique de Louvain, Brussels, Belgium.
authors.forename: Michel
authors.initials: M
authors.lastname: Delmée
authors.affiliation: National Reference Centre for Monitoring Antimicrobial Resistance in Gram-negative bacteria, CHU UCL Namur, Yvoir, Belgium.
authors.forename: Youri
authors.initials: Y
authors.lastname: Glupczynski
mesh_terms: D000890:Anti-Infective Agents / Q000627:therapeutic use*; D001431:Bacteriological Techniques; D000071997:Blood Culture; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D018805:Sepsis / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013203:Staphylococcal Infections / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000890:Anti-Infective Agents