RATA: A novel class A carbapenemase with broad geographic distribution and potential for global spread

Carbapenem resistance is a global health issue, primarily due to carbapenemase production. A new carbapenemase, RATA, was discovered in Riemerella anatipestifer isolates, which shares a 52% amino acid sequence identity with other β-lactamases. RATA hydrolyzes penicillins, cephalosporins, monobactams, cephamycins, and carbapenems and can be inhibited by β-lactamase inhibitors. Bioinformatic analysis revealed 46 blaRATA-like genes encoding 27 variants, primarily from marine environments. blaRATA orthologue genes were found on Flavobacteriaceae chromosomes, sharing similar GC content. The study suggests RATA is a new chromosome-encoded class A carbapenemase.