Short Incubation of Positive Blood Cultures on Solid Media for Species Identification by MALDI-TOF MS: Which Agar Is the Fastest?
Neele J. Froböse, Evgeny A. Idelevich, Frieder Schaumburg
Abstract
When blood cultures are flagged as positive, they are incubated on solid media to produce enough biomass of the bacterium for identification and susceptibility testing. Rapid turnaround times for laboratory results could save lives, and we wanted to assess which solid medium is best to shorten the time to species identification using MALDI-TOF mass spectrometry. For that purpose, we used positive blood cultures from routine diagnostics and compared Columbia blood agar (CBA), Chocolate agar (Choc), and MacConkey agar (MAC, for Gram-negative rods). We found that MAC performed best for Gram-negative rods and CBA was quickest for Gram-positive cocci. However, Choc may represent a compromise if fastidious species should be covered.