The evolutionary history of the metallo-beta-lactamases (MBLs)
In a new publication, CARe scientists present an updated phylogeny of the MBLs showing that the majority of the today clinically relevant MBLs were mobilized from bacteria of the phylum Proteobacteria.
Metallo-beta-lactamases (MBLs) are enzymes that confer resistance to almost all available beta-lactam antibiotics, including carbapenems – a class of last-resort drugs used for life-threatening infections. The number of different forms of MBLs encountered in pathogenic bacteria is constantly increasing, but none of the common variants have a known origin from where it was mobilized and transferred. In a new publication, the CARe members Fanny Berglund, Anna Johnning, Joakim Larsson and Erik Kristiansson present an updated phylogeny of the MBLs showing that the majority of the today clinically relevant MBLs were mobilized from bacteria of the phylum Proteobacteria. In addition, several new variants of the MBLs were discovered, and many of these had variations in their active sites that could potentially alter their biochemical properties. The updated phylogeny shows that the MBLs can be further divided into subgroups that reflect the taxonomy of the host species and the variations in their active sites, enabling a more precise categorization where new genes could directly be put into a more detailed taxonomic and evolutionary context.