{ "abstract": "Carbapenem-resistant Klebsiella pneumoniae (CRKP) is the pathogen driving the deterioration of the European antimicrobial resistance landscape, and the burden falls disproportionately on Romania and South-Eastern Europe. The objective of this review was to synthesise evidence published between 2020 and 2025 on the epidemiology, molecular characteristics, clinical impact, and pandemic-era trajectory of CRKP healthcare-associated infections across South-Eastern Europe, including Romania. This retrospective, qualitative narrative review combined the international literature with a deliberately multilingual search of national-language sources in Romanian, Bulgarian, Greek, Croatian, Slovenian, and Serbian, including congress abstract books, doctoral theses, national reference-laboratory reports, and agency surveillance series that are absent from PubMed. Three findings emerge. First, the region is not epidemiologically uniform: estimated incidence of carbapenem-resistant K. pneumoniae bloodstream infection in 2024 ranged from 0.62 per 100,000 population in Slovenia to 20.31 in Romania, against a European Union/European Economic Area (EU/EEA) figure of 3.46, and the steepest relative rise between 2019 and 2024 was recorded in Bulgaria (+374.1%). Second, a distinctive molecular signature has consolidated in the northern half of the region: co-production of a metallo-β-lactamase with an OXA-48-like enzyme (OXA-48, a class D, oxacillinase-type carbapenemase), reported in 44.4-61.2% of characterised Romanian isolates across independent centres, which removes ceftazidime-avibactam from the therapeutic repertoire and leaves aztreonam-avibactam and cefiderocol as the principal remaining options. Third, the pandemic did not produce a single regional signal but a consistent sequence-a transient interruption of upward trends during 2020, a marked acceleration from 2021, and persistence of the elevated level after 2022-with national-language surveillance from Croatia and Slovenia showing that the direction of the apparent pandemic effect depends on whether incidence or resistance proportion is measured. The national-language literature adds granularity unavailable in English, but the evidence base remains structurally uneven: Albania, Kosovo, and North Macedonia contribute almost no primary data, and no country in the region has published a CRKP-attributable mortality estimate for the review period. CRKP in Romania and South-Eastern Europe now maps onto three molecular zones-OXA-48 predominance in the Western Balkans and Croatia, a KPC-to-metallo-β-lactamase transition in Greece, and metallo-β-lactamase plus OXA-48-like co-production in Romania and increasingly Bulgaria-that require different empirical therapy; the COVID-19 pandemic did not create this burden but accelerated and entrenched it, and closing the region's mortality-data and Western Balkan surveillance gaps should be a priority for future research.", "abstract_shown": true, "affiliations": [ "Department of Infectious Diseases and Epidemiology, Faculty of Medicine, Ovidius University of Constanta, 1 University Alley, 900470 Constanta, Romania.", "Clinical Infectious Diseases Hospital, Ferdinand Blvd. No. 100, 900709 Constanța, Romania.", "Doctoral School, Faculty of Medicine, Ovidius University of Constanta, 1 University Alley, 900470 Constanta, Romania.", "County Clinical Emergency Hospital \"St. Apostle Andrew\", Tomis Blvd. No. 145, 900591 Constanța, Romania.", "Department of Public Health and Management, Faculty of Medicine, Ovidius University of Constanta, 1 University Alley, 900470 Constanta, Romania.", "Service of Infectious Diseases, University Hospital Center \"Mother Teresa\", 1007 Tirane, Albania.", "Department of Epidemiology I, University of Medicine and Pharmacy \"Carol Davila\", Bd. Eroii Sanitari 8, Sector 5, 050474 Bucharest, Romania.", "National Institute of Infectious Diseases \"Prof. Dr. Matei Balș\", 1 Dr. Calistrat Grozovici Street, District 2, 021105 Bucharest, Romania.", "Faculty of Medicine, University of Medicine and Pharmacy \"Carol Davila\", Bd. Eroii Sanitari 8, Sector 5, 050474 Bucharest, Romania.", "\"Prof. Dr. Agrippa Ionescu\" Emergency Clinical Hospital, 077015 Bucharest, Romania.", "Academy of Romanian Scientists, 3 Ilfov Street, 050044 Bucharest, Romania." ], "article_type": "review article", "arxiv": null, "author_total": 11, "authors": [ { "affs": [ 0, 1 ], "name": "Roxana-Carmen Cernat", "orcid": "0000-0002-0567-4958" }, { "affs": [ 1, 2 ], "name": "Oana-Elena Ioniţă" }, { "affs": [ 1, 2 ], "name": "Maria-Elena Vodarici" }, { "affs": [ 1, 2 ], "name": "Nicola-Maria Militaru", "orcid": "0009-0008-4213-7378" }, { "affs": [ 3 ], "name": "Rareș-Alexandru Constantin" }, { "affs": [ 1, 2 ], "name": "Nela-Daniela Efrim", "orcid": "0009-0009-8468-3913" }, { "affs": [ 4 ], "name": "Elena Mocanu", "orcid": "0000-0003-2386-543X" }, { "affs": [ 5 ], "name": "Edmond Puca", "orcid": "0000-0002-0621-4865" }, { "affs": [ 6, 7 ], "name": "Daniela Piţigoi", "orcid": "0000-0003-4118-8268" }, { "affs": [ 8, 9 ], "name": "Valeriu Gheorghiţă", "orcid": "0000-0002-7819-5464" }, { "affs": [ 0, 1, 2, 10 ], "name": "Irina-Magdalena Dumitru", "orcid": "0000-0003-0395-6713" } ], "bibtex": "https://research.draconitic.com/paper/0r0cmn42wk2x5.bib", "cited_by": 0, "doi": "10.3390/pathogens15101004", "fulltext_url": "https://europepmc.org/articles/PMC13708726", "id": "0r0cmn42wk2x5", "issns": [ "2076-0817" ], "landing_url": "https://europepmc.org/article/MED/42931156", "language": "eng", "licence": "CC-BY", "licence_label": "CC BY", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "openalex", "1313|Antibiotic Resistance in Bacteria" ] ], "openalex": "W7213972551", "pdf_url": "https://europepmc.org/articles/PMC13708726?pdf=render", "pmcid": "PMC13708726", "pmid": "42931156", "published": "2026-09-22", "publisher": null, "ris": "https://research.draconitic.com/paper/0r0cmn42wk2x5.ris", "sources": [ { "first_seen": "2026-10-30T12:22:02Z", "native_id": "MED:42931156", "source": "europepmc", "url": "https://europepmc.org/article/MED/42931156" } ], "subjects": [ { "field": "medicine", "origin": "openalex:1313|Antibiotic Resistance in Bacteria", "subfield": "general" } ], "title": "Carbapenem-Resistant Klebsiella pneumoniae in Romania and South-Eastern Europe: A Multilingual Narrative Review of Pandemic-Era Trajectories, 2020-2025.", "title_text": "Carbapenem-Resistant Klebsiella pneumoniae in Romania and South-Eastern Europe: A Multilingual Narrative Review of Pandemic-Era Trajectories, 2020-2025.", "type": "peer-reviewed", "updated_at": "2026-10-30T12:22:02Z", "url": "https://research.draconitic.com/paper/0r0cmn42wk2x5", "venue": "Pathogens (Basel, Switzerland)", "versions": [] }