Selection and characterization of a Vibrio parahaemolyticus OmpU antibody by phage display

Vibrio parahaemolyticus (V. parahaemolyticus) is a well-known food-borne human pathogen that can cause a variety of clinical manifestations after the consumption of raw or undercooked seafoods. The crucial roles of Vibrio OmpU in bacterial pathogenesis have been found in recent studies. In the present study, we screened for single domain antibody fragment (sdAb) candidates that bind to V. parahaemolyticus OmpU by using a sdAb phage display library and isolated several positive phage clones. The UAb28, which was one of the positive clones, was shown high enrichment and affinity. The CDRs of UAb28 are speculated to perform the OmpU binding function by molecular docking. The capable of recognizing OmpU was verified by binding and inhibition assays. The UAb28 might be useful in future studies to develop the potential sdAb-based immunotherapeutics against V. parahaemolyticus infection.