RAPID DETECTION OF ANTIMICROBIAL ACTIVITY USING FLOW-CYTOMETRY

Different antibiotic classes vary considerably in their modes of actio n and hence in their effects on the bacterial cell. Flow cytometry was used to analyse E. coli cells treated with five antibiotics differing in their modes of action, The ratio of protein content, as measured b y fluorescence, to forward light scatter (i.e., FL1:FSC) provided a si mple and reliable way of detecting within 2 h of treatment antimicrobi al activity at a 0.5 minimum inhibitory concentration, This ability to detect antimicrobial activity rapidly offers considerable advantages in drug research for the rapid detection of novel antimicrobials and m ay, with further development, find a use in the clinic for rapid susce ptibility testing as an aid to the selection of therapy. (C) 1995 Wile y-Liss, Inc.