Phylogenetic predictions of carbapenemase activity from the Guiana extended-spectrum (GES) family of β-lactamases.

Objectives: We investigated the amino acid substitutions in the GES family of ESBLs that were most likely to be involved in the evolution of carbapenemase activity.
Methods: To identify the substitutions that are functionally important, we analysed the evolutionary history of the GES β-lactamases using an alignment and phylogeny to identify sites in GES that show evidence of positive selection and the selected phenotypes.
Results and Conclusions: Data indicate that the substitutions G170S and G243A are associated with carbapenemase activity. The substitutions Q43E, E104K and T237A are most likely associated with ESBL activity.
(© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)