NDM-2 carbapenemase in Acinetobacter baumannii from Egypt

To analyse the mechanisms responsible for carbapenem resistance in one Acinetobacter baumannii isolate recovered from a patient transferred to Germany from an Egyptian hospital.

PCR and sequencing were used to search for β-lactamase and 16S RNA methylase genes. Multilocus sequence typing was used to determine the sequence type (ST) of the isolate.

Sequencing of the PCR product obtained using primers for bla(NDM-1) revealed a variant of NDM-1 that had a C to G substitution at position 82 resulting in an amino acid substitution of proline to alanine at position 28. This variant was designated NDM-2. Genes encoding extended-spectrum β-lactamases or 16S RNA methylase were not detected. The strain lacked detectable plasmids and bla(NDM-2) was not transferred by conjugation. MLST showed that the isolate belonged to a new ST, ST103.

This work further underlines the spread of NDM carbapenemases in A. baumannii, and the spread of the corresponding gene in the Middle East. It also describes the first variant of NDM-1.