OXA-24-like carbapenemase genes among carbapenem-resistant Acinetobacter baumannii isolates from a clinical hospital centre in Zagreb, Croatia

Recently, in the University Hospital Centre Zagreb (UHCZ), Croatia emergence of carbapenem-resistant A. baumannii isolates was noticed. The aim of this study was to investigate strain relatedness and carbapenemase encoding genes in carbapenem-resistant isolates.So far, the genes encoding OXA-24-like enzyme were confined to isolates from Spain and Portugal, and recently one isolate was also reported from Czech Republic. Here we report the occurrence of a major cluster of A. baumannii strains in our hospital in Zagreb in which carbapenem-resistance was associated with OXA-24-like carbapenemase genes. This cluster did not correspond to any of European clones I-III. Nevertheless, we found strains belonging to European clone I, but they were not carbapenem-resistant.