Background: Selective pressure drives SARS-CoV-2 evolution, with spike RBD substitutions shaping ACE2 binding and antibody escape. N481K RBD mutation emerged early in Qatar (2020) and later re-emerged globally, reaching near-fixation by 2024–2025, yet its functional significance remained unexplored. Methods: We analyzed the temporal and geographic circulation of N481K across > 17 million SARS-CoV-2 genomes (2020–2025). Structu...

Lactococcus garvieae , Lactococcus petauri and Lactococcus formosensis are etiological agents of piscine lactococcosis, a disease reported in Italy since the early 1990s and linked to significant aquaculture losses. To the best of our knowledge, this study reports the first detection of L. formosensis subsp. formosensis in farmed rainbow trout ( Oncorhynchus mykiss ) in Europe. In 2024, a total of 70 trout were sampled in the...