Phylogenetic network of infectious bronchitis virus: exploring the impact of migratory birds on viral clustering, evolution, and recombination.

Infectious bronchitis virus (IBV) presents a major threat to global poultry production, necessitating a thorough understanding of its evolutionary relationships for effective control measures. This study presents a novel distance-based Minimum Span Clustering (MSClustering) method to cluster 311 IBV strains, with a comparison of its results to the established IBV classification. Phylogenetic network and recombination analyses were employed to investigate IBV evolutionary relationships and transmission pathways. The phylogenetic network revealed distinct clusters reflecting relationships between IBV strains. Importantly, these network patterns, combined with recombination event analysis, suggest an unrecognized role for migratory birds in IBV dissemination, highlighting potential transmission pathways beyond established poultry trade routes. These findings contribute to advancing our understanding of IBV evolution and support the development of targeted strategies for controlling viral outbreaks in poultry populations. While statistical limitations may affect threshold estimation for smaller networks, our MSClustering method significantly accelerates processing speeds-approximately 100,000 times faster than PhyML when analyzing the dataset-enabling comprehensive-scale phylogenetic analysis of viruses.