Modeling bacteriophage attachment using adsorption efficiency

Typically, models of bacteriophage adsorption consider the process in two steps: reversible and irreversible attachment. In this study, a recently introduced one-step adsorption model, the adsorption efficiency model, is used to describe the adsorption of T-series bacteriophages to Escherichia coli. The adsorption efficiency model simplifies phage attachment to a single step: irreversible binding. The adsorption efficiency (ɛ) is used to account for unadsorbed phages. The model accurately describes T-series phage adsorption (T2, T4, T5, T6, and T7) under a variety of conditions. In addition, the model is compared to a commonly used two-step adsorption model, the sequential model. Experimental data support the assumptions of the adsorption efficiency model and suggest that the reversible first step of T-series phage adsorption is equivalent to irreversible attachment under the conditions tested. The adsorption efficiency model was not appropriate for a phage λ strain lacking side tail fibers. However, the model did agree with data previously published for a strain of phage λ possessing side tail fibers, as is the case of all T-series strains tested. This suggests that the adsorption efficiency model applies to phages containing side tail fibers

► Demonstrates robustness of adsorption efficiency model.
► Shows the applicability of adsorption efficiency model to different phages.
► Gives experimental support for assuming reversible step in adsorption is negligible.
► Demonstrates better fit of model compared to common sequential adsorption model.
► Shows limits to model, e.g. it does not apply to phages without side tail fibers adsorption.