Rapid screening for specific glycosylation and pathogen interactions on a 78 species avian egg white glycoprotein microarray

There is an urgent need for discovery of novel antimicrobials and carbohydrate-based anti-adhesive strategies are desirable as they may not promote resistance. Discovery of novel anti-adhesive molecules from natural product libraries will require the use of a high throughput screening platform. Avian egg white (EW) provides nutrition for the embryo and protects against infection, with glycosylation responsible for binding certain pathogens. In this study, a microarray platform of 78 species of avian EWs was developed and profiled for glycosylation using a lectin panel with a wide range of carbohydrate specificities. The dominating linkages of sialic acid in EWs were determined for the first time using the lectins MAA and SNA-I. EW glycosylation similarity among the different orders of birds did not strictly depend on phylogenetic relationship. The interactions of five strains of bacterial pathogens, including Escherichia coli, Staphylococcus aureus and Vibrio cholera, identified a number of EWs as potential anti-adhesives, with some as strain-or species-specific. Of the two bacterial toxins examined, shiga-like toxin 1 subunit B bound to ten EWs with similar glycosylation more intensely than pigeon EW. This study provides a unique platform for high throughput screening of natural products for specific glycosylation and pathogen interactions. This platform may provide a useful platform in the future for discovery of anti-adhesives targeted for strain and species specificity.This work was funded by Science Foundation Ireland (SFI) grant numbers 11/TIDA/I2044 in support of a Technology Innovation Development Award, 08/SRC/B1393 in support of the Alimentary Glycoscience Research Cluster and 07/SK/B1250 for Stokes Professor for Glycosciences (LJ), and the European Union FP7 grant number 260600 in support of the GlycoHIT consortium. The authors thank Prof. James O’Gara and Ms Andrea Flannery for the gift of S. aureus strains and Dr. Aoife Boyd for V. parahaemolyticus. Y.C.L. thanks the late Dr. M. Laskowski, Jr. for generously providing the invaluable egg white collection, which he was gifted over the course of many years by various donors including zoos, research institutes and game preserves. Bird eggs should not be collected from the wild without ethical approval from the relevant national or international governing body.peer-reviewe