Facing SARS-CoV-2 emergence on the animal health perspective: The role of the World Organisation for Animal Health in preparedness and official reporting of disease occurrence.

AIMS: Current data suggest that SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) emerged from an animal source. However, to date, there is insufficient scientific evidence to identify the source of SARS-CoV-2 or to explain the original route of transmission to humans. A wide range of mammalian species have been shown to be susceptible to the virus through experimental infection, and in natural environments when in contact with infected humans. The main objective of this work was to provide a summary of the official data shared by countries on SARS-CoV-2 in animals with the World Organisation for Animal Health (WOAH), to highlight the role of WOAH as an international organization in coordinating scientific information actions and to discuss the implications and impact of these activities. METHODS AND RESULTS: Between January 2020 and December 2022, 36 countries in Europe, the Americas, Asia and Africa officially reported SARS-CoV-2 identification in 26 animal species. Affected countries were generally responsive in confirming the pathogen (median of 5 days after onset) and reporting to WOAH (median of 7 days after confirmation). CONCLUSIONS: During the pandemic, WOAH, supported by its network of experts, played a crucial role in collecting, analysing and disseminating veterinary scientific information, acting as the reference organization on these issues, thus avoiding misinformation and disinformation. Future perspectives to avoid new emerging threats are discussed.

New Leishmania donovani nucleoside hydrolase inhibitors from Brazilian flora.

This study presents new inhibitors of the nucleoside hydrolase from Leishmania donovani (LdNH) with in vitro leishmanicidal activity. Biological screening of 214 Brazilian plant extracts was performed to select plants with enzyme inhibitory activity. Two plants were selected for their results, and for their lack of prior phytochemical description: Leandra amplexicaulis DC. (Melastomataceae) and Urvillea rufescens Cambess (Sapindaceae). Three flavonoids were isolated by bioguided fractionation of the hydroethanolic extracts: kaempferol 3-O-α-l-rhamnopyranoside (1) and kaempferol 3-O-ß-d-xylopyranosyl-(1→2)-α-l-rhamnopyranoside (2) from L. amplexicaulis, as well as tricetin-4'-O-methyl flavone (3) from U. rufescens. These flavonoids showed inhibitory activities (IC50) of 197.4 µM (1), 74.7 µM (2) and 1.1 µM (3) on the LdNH. Their binding mode was proposed based on molecular docking with LdNH and by NMR Saturation Transfer Difference studies. Kinetic studies demonstrate that the most potent inhibitor (3) acts by uncompetitive inhibition. This study reports for the first time the inhibition of LdNH by naturally sourced flavonoids.