Hypervirulent Klebsiella pneumoniae (hvKP) can cause severe infections even in healthy individuals. Currently, no data are available on the frequency of hvKP-induced bloodstream infections (BSI) in Hungary. Our investigation revealed that of the 157 K . pneumoniae isolated from BSI in 2020–2022 at a university hospital in Hungary, three (2%) carried the hypervirulence-associated rmpA and iutAiucABCD genes. The complete genomes of these three hvKP isolates were sequenced. They were unrelated and belonged to ST5, ST86, and ST6771, a single-locus variant of ST893, i.e., to internationally known hvKP clones. In the K. pneumoniae ST86 and ST6771 isolates, the rmpA/A2 , aerobactin, and salmochelin siderophore genes were located on virulence plasmids highly similar to those of K. pneumoniae ST23 and ST86 isolated in Asia, while the K. pneumoniae ST5 isolate harboured rmpA , iroBCDN , and yersiniabactin locus on a chromosomally integrated ICE Kp1 element. Comparison of the core genome MLST of the three Hungarian hvKP isolates to genomes belonging to the same ST/CC deposited in the Bigsdb database of the Pasteur Institute revealed that, although no direct epidemiological link could be established, KP48326 K. pneumoniae ST86, isolated in Pécs, clustered with a Greek isolate (ID-48733). The emergence of K. pneumoniae belonging to known hypervirulent clones in Hungary, albeit sporadic, is alarming and underscores the importance of continued whole-genome-based epidemiological surveillance. IMPORTANCE: This study represents the first investigation of the prevalence of hypervirulent K. pneumoniae (hvKP) in bloodstream infections in Hungary, conducted at the University Hospital of Pécs. Our findings emphasize the need to accurately identify hvKP strains, integrating both phenotypic and genotypic screening. Whole genome sequencing revealed genetic diversity among the Hungarian hvKP isolates, confirming the emergence of globally disseminating hvKP clones—ST86, CC893, and ST5—in Hungary. The localization of hypervirulence-related genes on mobile genetic elements, e.g., on virulence plasmids or on ICE Kp1 similar to those found in hvKP isolates from different continents, underscores the significant role of horizontal gene transfer in the spread of hvKP. Overall, the study enhances our understanding of hvKP epidemiology and underscores the importance of continued molecular surveillance and control measures to mitigate the threat of hvKP infections in Hungary.

Background: Carbapenem-resistant Escherichia coli (CREC) producing OXA-48-like carbapenemase was first detected in Hungary in 2022. The aim of the present study was to characterize such strains isolated in 2022–2025 in Baranya County, Hungary. Methods: Antibiotic susceptibility and the whole-genome sequence (WGS) of E. coli isolates, identified as OXA-48-like carbapenemase producers using the CARBA-5 NG test, were established. The transferability of bla_OXA-48-like plasmids was tested by conjugation. Results: Of the 6722 non-repeat E. coli isolates, 6 produced an OXA-48-like carbapenemase. They exhibited variable resistance to ertapenem and were susceptible to imipenem and meropenem. WGS revealed that all OXA-48-like producer E. coli belonged to high-risk clones: two clonally related OXA-181-producer E. coli ST405 were isolated in Hospital A, three OXA-244-producing E. coli ST38 (two identical via cgMLST from Hospital B), and an OXA-48-producing E. coli ST69. The bla_OXA-48 and bla_OXA-244 genes were chromosomally located, while bla_OXA-181 was on a non-conjugative IncFIB-IncFIC plasmid. So far, the bla_OXA-181-bearing plasmid of this incompatibility type has only been described in Ghana, but all bla_OXA-48-like gene-carrying transposons in this study have already been identified in Europe and other continents. The E. coli ST38 isolates, showing close association based on core genome SNP distances to European and Qatari strains, belonged to Cluster A and harbored bla_CTX-M-27. All but the E. coli ST69 isolate had cephalosporinase gene(s). Conclusions: This study describes small-scale intra-hospital transfers of OXA-48-like carbapenemase-producer E. coli. Interestingly, E. coli ST405 of Hungary carried bla_OXA-181 on an IncFIB-IncFIC plasmid, which has only been reported from Africa so far.