Ekwu M Ameh1, Sean Tyrrel1, Jim A Harris2, Mark Pawlett3, Elena V Orlova4, Athanasios Ignatiou4, Andreas Nocker1,5. 1. Cranfield Water Science Institute, School of Environment, Energy and Agrifood, Cranfield University, Cranfield, Bedfordshire, United Kingdom. 2. Cranfield Institute for Resilient Futures, School of Environment, Energy and Agrifood, Cranfield University, Cranfield, Bedfordshire, United Kingdom. 3. Cranfield Soil and Agrifood Institute, School of Environment, Energy and Agrifood, Cranfield University, Cranfield, Bedfordshire, United Kingdom. 4. Department of Biological Sciences, Institute for Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom. 5. Applied Microbiology, IWW Water Centre, Mülheim an der Ruhr, Germany.
Abstract
Background: Although bacteriophages see a revival for specifically removing undesired bacteria, there is still much uncertainty about how to achieve the most rapid and long-lasting clearance. Materials and Methods: This study investigated the lysis kinetics of three distinct environmental coliphages, reproducibly forming different plaque sizes (big, medium, and small). Lysis performance by individual phages was compared with the one obtained after simultaneous or sequential addition of all three phages. Kinetics was monitored by density absorbance or by flow cytometry, with the latter having the advantage of providing higher sensitivity. Results: Plaque size happened to correlate with lysis kinetics in liquid suspensions, with phages producing big (phage B), medium (phage M), and small (phage S) plaques showing maximal bacterial clearance under the chosen conditions within ∼6, 12, and 18 h, respectively. Use of a phage cocktail (all three phages added simultaneously) resulted in slower initial lysis compared with the fastest lysing phage with the greatest plaque size alone, but it showed longer efficacy in suppression. When adding phages sequentially, overall lysis kinetics could be influenced by administering phages at different time points. The lowest bacterial concentration after 36 h was obtained when administering phages in the sequence S, M, and B although this combination initially took the longest to achieve bacterial clearance. Conclusions: Results support that timing and order of phage addition can modulate strength and duration of bacterial suppression and, thus, influence the overall success of phage treatment. Copyright 2020, Mary Ann Liebert, Inc., publishers.
Background: Although bacteriophages see a revival for specifically removing undesired bacteria, there is still much uncertainty about how to achieve the most rapid and long-lasting clearance. Materials and Methods: This study investigated the lysis kinetics of three distinct environmental coliphages, reproducibly forming different plaque sizes (big, medium, and small). Lysis performance by individual phages was compared with the one obtained after simultaneous or sequential addition of all three phages. Kinetics was monitored by density absorbance or by flow cytometry, with the latter having the advantage of providing higher sensitivity. Results: Plaque size happened to correlate with lysis kinetics in liquid suspensions, with phages producing big (phage B), medium (phage M), and small (phage S) plaques showing maximal bacterial clearance under the chosen conditions within ∼6, 12, and 18 h, respectively. Use of a phage cocktail (all three phages added simultaneously) resulted in slower initial lysis compared with the fastest lysing phage with the greatest plaque size alone, but it showed longer efficacy in suppression. When adding phages sequentially, overall lysis kinetics could be influenced by administering phages at different time points. The lowest bacterial concentration after 36 h was obtained when administering phages in the sequence S, M, and B although this combination initially took the longest to achieve bacterial clearance. Conclusions: Results support that timing and order of phage addition can modulate strength and duration of bacterial suppression and, thus, influence the overall success of phage treatment. Copyright 2020, Mary Ann Liebert, Inc., publishers.
Authors: Remco Kort; Andreas Nocker; Alie de Kat Angelino-Bart; Sjaak van Veen; Herman Verheij; Frank Schuren; Roy Montijn Journal: BMC Biotechnol Date: 2010-06-18 Impact factor: 2.563