DYNAMICS OF BACTERIOPHAGE-HOST INTERACTIONS
P. E. Sørensen (patricia.sorensen@ugent.be)
1,2, A. Garmyn
1, H. Ingmer
3, and P. Butaye
1,21 Ghent University, Belgium, 2 Ross University School of Veterinary Medicine, St. Kitts, 3 University of Copenhagen, Denmark
Background
As an alternative or supplement to antibiotics, bacteriophages (phages) can be used as therapeutics (phage therapy, PT) to treat bacterial infections1,2. Understanding the phage-bacterium interactions and population dynamics is essential for successful PT application3. Here, we investigated the growth dynamics ofE. coli-infecting phages (coliphages) and avian pathogenicEscherichia coli(APEC), an important bacterial pathogen affecting poultry worldwide.
Methods
Phage-host growth dynamics of 18 lytic coliphages and 10 APEC strains (with serotype O1, O2, or O78) were assessed altering the parameters: phage species, APEC strain, and multiplicity of infection (MOI) using microtiter plate-based assays4.
Conclusion
This study provides new insights into the phage-host interaction dynamics. These findings constitute initial steps in developing PT against pathogenic E. coli.
However, in order to fully understand the complexity of the phage-host interaction dynamics, the underlying mechanisms behind these different interactions need to be deciphered.
This project has received funding from the EuropeanUnion’sHorizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement no. 765147
Results
Results showed 11 distinct growth patterns (Fig. 1), including
• A fully resistant pattern, representing the normal bacterial growth curve.
• A fully susceptible pattern showing no bacterial growth.
• Nine in-between patterns, characterized by lower killing, delayed killing or variable killing of the bacterial cells.
A comparison of the patterns reveals that phage, bacterial host, and MOI affect the phage-host interactions. This may influence the pharmacodynamics of a PT.
References: 1Huff W E et al., (2004). Poult Sci. 83(12). 2Wernicki A et al., (2017). Virol J. 14(1). 3Casey E et al., (2018). Viruses. 10(4). 4Xie Y et al,. (2018). Viruses. 10(4) 0,0
0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0
OD600
Time of incubation (min)
Coliphage-host growth dynamics
AM642 (MOI 1) AM621 (MOI 10) AM644 (MOI 0.1) AM644 (MOI 1) AM631 (MOI 1) AM644 (MOI 0.1) AM631 (MOI 1) AM639 (MOI 1) AM631 (MOI 10) AM650 (MOI 0.1) AM650 (MOI 1)
GD 1 (R) GD 2 GD 3 GD 4 GD 5 GD 6 GD 7 GD 8 GD 9 GD 10 GD 11 (S)
Fig. 1 | Grow th dynamics (GD) of coliphage and A PEC. R = Fully resistant pattern w ith phage- resistant APEC. S = Fully susceptible pattern w ith phage-susceptible APEC.
