DENVER — Using matrix-assisted laser desorption ionization time-of-flight mass spectrometry, or MALDI-TOF, decreased the time necessary to identify the organism causing bloodstream infections and may improve time to appropriate antibiotic treatment, according to data presented here at the 2013 Interscience Conference on Antimicrobial Agents and Chemotherapy.
MALDI-TOF has recently transitioned from the research setting into clinical laboratories, and data on the clinical effect of its use are now emerging, according to Katherine Bond, MD, of St. Vincent’s Hospital in Melbourne, Australia.
“The initial studies of MALDI-TOF evaluated its efficacy, but now we are looking to see if that translates into a clinical benefit,” Bond told Infectious Disease News. “It is widely known that earlier use of appropriate antibiotics for the management of bloodstream infections is likely to reduce patient mortality, and our study showed that MALDI-TOF significantly reduced the time to identification of the causative organism by a median of 10 hours, 45 minutes.”
Bond and colleagues conducted a retrospective review to evaluate the time to identification of the causative agent of a bloodstream infection using MALDI-TOF compared with standard processing of positive blood cultures. In the standard period, there were 68 episodes evaluated, and during the intervention period in which MALDI-TOF was used, there were 53 episodes evaluated.
The median time to identification of organism was 27 hours, 37 minutes among the episodes that used standard processing vs. 16 hours, 52 minutes among the episodes in which MALDI-TOF was used. The proportion of patients who were on appropriate antimicrobial therapy at 24 hours was not different. However, among a subgroup of 18 patients with a spectral score of more than 2, all were on appropriate therapy.
“The clinical impact of MALDI-TOF will likely depend on several factors, including the threshold spectral score used for correct identification and the number of isolates successfully identified by technique,” Bond said. “It could also be affected by the degree to which local epidemiological resistance patterns can be inferred from species identification and by local prescribing practices.”
Katherine Bond, MD, can be reached at email@example.com.
For more information:
Bond K. #D-114. Presented at: ICAAC 2013; Sept. 10-13, 2013; Denver.
Disclosure: Bond reports no relevant financial disclosures.