Class D Beta- Lactamases

This class includes:

The OXA group of β-lactamases mainly occur in Acinetobacter species and are divided into two clusters. OXA carbapenemases hydrolyse carbapenems very slowly in vitro, and the high MICs seen for some Acinetobacter hosts (>64 mg/L) may reflect secondary mechanisms. They are sometimes augmented in clinical isolates by additional resistance mechanisms, such as impermeability or efflux