Co-occurrence of triple carbapenemase genes, bla VIM-2, bla NDM-1, and bla OXA-48 in Enterobacter hormaechei clinical isolates –first report from Croatia

Abstract

Two Enterobacter hormaechei isolates harbouring three carbapenemase genes each, were isolated from two patients from different ICUs at University Hospital Centre Zagreb, Croatia, which is to our knowledge, the first report of triple carbapenemase (bla VIM-2, bla NDM-1, and bla OXA-48 ) co-existence in E. hormachei strains and also among Enterobacterales members in Croatia. Antimicrobial susceptibility testing showed susceptibility only to colistin and amikacin. The production of carbapenemases was phenotypically tested by immunochromatographic assay and confirmed by PCR. Detailed analysis by Whole Genome Sequencing (WGS) of short reads by Illumina and long reads by Oxford Nanopore Technologies (ONT) was additionally performed and showed that both isolates belonged to ST200. They were separated by 98 Single Nucleotide Polymorphisms (SNPs) having variations in the number of bla VIM-2 genes on the chromosome, the number of bla NDM-1 genes on the plasmid, non-identical bla NDM-1 plasmids, different plasmid content in general, and only one isolate carried a 94 kb prophage.