Phage Susceptibility Assay

Along with over a decade of rich experience in providing excellent customer services for phage therapy, Creative Biolabs has won a good reputation among our worldwide customers for successfully accomplishing numerous challenging projects. Equipped with world-leading technology platforms and professional scientific staff, now we can provide novel phage susceptibility assays for our clients all over the world.

Introduction of Phage Susceptibility

Phage therapy is a strong alternative to antibiotics and has served as a promising solution for persistent and resistant bacterial infections. The choice of antimicrobial agents often depends on the susceptibility profile of the pathogen. In the past decades, antimicrobial susceptibility testing has substantially evolved to ensure reliability and reproducibility in clinical treatment. Phage susceptibility test will enable rapid identification of patient-specific treatments for challenging bacterial infections, especially those with antimicrobial resistance (AMR) or with biofilms.

For clinical use, the bacterial pathogens isolated from the patients would be used for the bacteriophage susceptibility test. In spot testing, the effective phage is added to the bacterial lawn of the target host strain for cultivation. Phage lysis of the target strain will appear as visible lysis plaques on the agar surface.

Fig.1 Drops of bacteriophages 44AHJD and K were incubated with Staphylococcus aureus, lysing the cells and producing regions of lysis. (O'Connell, et al., 2021)

Phage Susceptibility Assay

In a clinical context, Kirby-Bauer or disk diffusion test is a classic phage susceptibility test assay. According to the agar-based phage susceptibility assay, the most active phages against bacterial targets can be identified. Traditionally, culture-based approaches account for susceptibility through direct visual detection of plaques. To better study phage plaque growth kinetics and accelerate diagnosis in phage therapy, the novel wide-field lensless imaging method has been developed. Under the selective pressure of bacteriophages, bacterial clones can form microcolonies within plaques and be imaged via lensless imaging. Experimental data suggest that lensless imaging can be used as an effective tool to detect possible resistance of phages to bacterial strains. What's more, surface plasmon resonance imaging (SPRi) and phase imaging are also candidates for rapid phage susceptibility assay in the broth phase.

Fig.2 A schematic illustration of the SPRi prism and phase imaging microscope. (O'Connell, et al., 2022)

Creative Biolabs offers the most advanced and comprehensive phage susceptibility assays. We work to amplify your success in a highly collaborative manner. If you are interested in our services, please do not hesitate to contact us for detailed information.

References:

1. O'Connell, L.; et al. Ultrafast and multiplexed bacteriophage susceptibility testing by surface plasmon resonance and phase imaging of immobilized phage Microarrays. Chemosensors. 2022, 10(5): 192.
2. Neguţ, A.C.; et al. Experimental approach for bacteriophage susceptibility testing of planktonic and sessile bacterial populations–Study protocol. Germs. 2014, 4(4): 92.
3. O'Connell, L.; et al. Optical bacteriophage susceptibility testing by SPR (surface plasmon resonance). Plasmonics in Biology and Medicine XVIII. SPIE, 2021, 11661: 36-47.