The use of bacteriophages, viruses that specifically
infect bacteria,
as antibiotics has become an area of great interest in recent years
as the effectiveness of conventional antibiotics recedes. The detection
of phage interactions with specific bacteria in a rapid and quantitative
way is key for identifying phages of interest for novel antimicrobials.
Outer membrane vesicles (OMVs) derived from Gram-negative bacteria
can be used to make supported lipid bilayers (SLBs) and thereforein vitromembrane models that contain naturally occurring
components of the bacterial outer membrane. In this study, we employedEscherichia coliOMV derived SLBs and use both fluorescent
imaging and mechanical sensing techniques to show their interactions
with T4 phage. We also integrate these bilayers with microelectrode
arrays (MEAs) functionalized with the conducting polymer PEDOT:PSS
and show that the pore forming interactions of the phages with the
SLBs can be monitored using electrical impedance spectroscopy. To
highlight our ability to detect specific phage interactions, we also
generate SLBs using OMVs derived fromCitrobacter rodentium, which is resistant to T4 phage infection, and identify their lack
of interaction with the phage. The work presented here shows how interactions
occurring between the phages and these complex SLB systems can be
monitored using a range of experimental techniques. We believe this
approach can be used to identify phages that work against bacterial
strains of interest, as well as more generally to monitor any pore
forming structure (such as defensins) interacting with bacterial outer
membranes, and thus aid in the development of next generation antimicrobials.