As a result of the increased numbers of bacteria
carrying ESBL genes, the clinical use of carbapenem antibiotics
has increased over the past decade. In turn, this
has been associated with increasing numbers of clinical
isolates carrying β‑lactamases with carbapenem-hydrolysing
activity (known as carbapenemases)119–121. Carbapenemases
mainly include members of the class A, B
and D β‑lactamases119–121. The hallmark of these enzymes
is the ability to inactivate a broad range of β‑lactams,
including carbapenems and extended-spectrum
cephalosporins. Although first identified on the chromosomes
of single species, many carbapenemases are
now plasmid-mediated and have been reported in
Enterobacteriaceae,