The Rise of OXA-48-like Carbapenemase-Producing E. coli in Hungary: Genomic Insights and Clinical Implications

OXA-48–like carbapenemase–producing Escherichia coli have emerged in Baranya County, Hungary, posing an immediate threat to acute-care settings. Hospitals should treat these isolates as a new local risk because they narrow available therapy options and have demonstrated potential for in-hospital spread.

Whole-genome sequencing of the Baranya County surveillance cohort (2022–2025; n=6 OXA-48–like producers identified from 6,722 non-repeat E. coli isolates) shows the producers cluster in recognized high-risk clones: two clonally related OXA-181–producing E. coli ST405, three OXA-244–producing E. coli ST38 (two identical by cgMLST), and one OXA-48–producing E. coli ST69. Notably, the molecular data link these phenotypes to an OXA-48-like carbapenemase genotype across the group and identify three distinct sequence types (ST405, ST38, ST69). The presence of high-risk clones in surveillance increases the probability of clustered outbreaks and delivers a clear genomic signal of concern.

Clinical and molecular epidemiology support intra-hospital transmission: two ST405 cases clustered in Hospital A and three ST38 cases clustered in Hospital B, with two ST38 isolates identical by cgMLST and close core-genome SNP distances to related European strains—findings consistent with recent transmission within wards and narrow temporal windows. The temporal and ward overlap of these cases provides concrete operational signals (identical cgMLST and low SNP divergence) rather than speculative links, supporting documented small-scale nosocomial spread within the participating hospitals.

Genetic localization data show blaOXA-48–like genes on both chromosomal loci and mobile elements: blaOXA-48 and blaOXA-244 were chromosomally integrated while blaOXA-181 was carried on a non-conjugative IncFIB–IncFIC plasmid. Several isolates co-harbored extended-spectrum β-lactamase genes such as blaCTX-M-27. Conjugation assays reported non-transferability of the IncFIB–IncFIC blaOXA-181 plasmid in this series, and transposon structures previously described in Europe were identified around the blaOXA-48–like loci. The combination of chromosomal integration and plasmid carriage broadens dissemination pathways and complicates containment strategies.

Enhanced genomic surveillance combined with tightened infection control measures is warranted to detect further introductions, limit intra-hospital spread, and track plasmid-mediated dissemination paths.

Key Takeaways:

• OXA-48–like E. coli have been identified in high-risk clones (ST405, ST38, ST69) in Baranya County. Who’s affected? Acute-care wards and vulnerable inpatients. Next steps: prioritize targeted surveillance and rapid molecular detection.
• Genomic clustering indicates intra-hospital spread (two ST405 cases in Hospital A; three ST38 cases in Hospital B, two identical by cgMLST). Who’s affected? Infection prevention teams and cohorting decisions. Next steps: review ward-level screening and contact tracing protocols.
• blaOXA-48–like genes appear on both chromosome and plasmid (non-conjugative IncFIB–IncFIC for blaOXA-181) and co-occur with ESBL genes. Who’s affected? Antimicrobial stewardship and regional surveillance networks. Next steps: expand genomic surveillance and monitor plasmid dynamics.