Genetic analysis of carbapenem resistant Acinetobacter baumannii isolates associated with the war in Ukraine

Question

The worldwide spread and increase of multidrug-resistant Gramnegative bacteria represents a serious threat to public health. However, the prevalence of resistance mechanisms may differ between different regions or countries. In case of Ukraine, high AMR proportions in Gram-negative bacterial isolates have been reported in 2021, including carbapenem resistant Acinetobacter spp. (73%) and carbapenem resistant Klebsiella pneumoniae (64%)1. Recently, an increase in NDM-1 and NDM-1/OXA-48-producing K. pneumoniae in Germany was observed that derived at least partially from patients with prior exposure in Ukraine2.

Here, we report genetic surveillance of carbapenem resistant A. baumannii isolates in Germany from patients with prior exposure in Ukraine.

Methods

Carbapenemase detection was performed at the German National Refence Laboratory for multidrug-resistant Gram-negative bacteria (NRC) by modified Hodge test, combined disk test with EDTA and PCR for carbapenemase genes. Whole-cell DNA was subjected to WGS on an Illumina MiSeq platform with 2 x 300 bp paired end reads and subsequent genome assembly and typing was conducted using Ridom SeqSphere.

Results

In total, 58 A. baumannii isolates from patients with prior exposure in Ukraine were sequenced. Most of the isolates produced the carbapenemases OXA-23 or OXA-72. The most prevalent sequence types (STs) were ST2 for OXA-23 positive isolates and ST78 for OXA-72 positive isolates. Comparison via core genome MLST (cgMLST) revealed several clusters distributed all over Germany.

Conclusions

We report genetic analysis of carbapenemase producing A. baumannii isolates from patients with prior exposure in Ukraine. The distribution of closely related isolates all over Germany suggests that transmission may have occurred during hospitalization in Ukraine or transfer to Germany.