To assess the spread of New Delhi metallo-β-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae ST147 organisms in Poland since an introduction from Tunisia in March 2015, including their phylogenetic position in the global population of the high-risk clone. Out of 8925 unique NDM-positive K. pneumoniae isolates identified in Poland from April 2015 till December 2019, 126 isolates, including the Tunisian imports, were related by PFGE and bla_NDM gene-carrying Tn125 transposon derivatives. Forty-seven representative isolates were sequenced by Illumina MiSeq. The phylogeny, resistome, virulome and plasmid replicons were analysed and compared with the international ST147 strains. Plasmids of six isolates were studied by the MinION sequencing. A high homogeneity of the 47 isolates was observed, with minor variations in their resistomes and plasmid replicon profiles. However, the detailed SNP comparison discerned a strict outbreak cluster of 40 isolates. All of the organisms were grouped within the ST147 phylogenetic international lineage, and four NDM-1 producers from Tunisia, Egypt and France were the closest relatives of the Polish isolates. Yersiniabactin genes (YbST280 type) were located within the ICEKpn12-like element in most of the outbreak isolates, characterized by O2v1 and KL64 antigen loci. The bla_NDM-1 genes were located in double-replicon IncFII_K2+IncFIB_K plasmids. The continuous spread of K. pneumoniae ST147 NDM-1 in Poland since 2015, largely in the Warsaw area, is demonstrated by this genomic analysis. The isolates showed a high degree of homogeneity, and close relatedness to organisms spreading in the Mediterranean region.

To characterize carbapenemase-producing isolates of the Klebsiella pneumoniae hypervirulent (hvKp) clone ST23 in Poland. Fifteen K. pneumoniae ST23 isolates were identified by the Polish surveillance of carbapenemase-producing Enterobacterales. These comprised a cluster with KPC-2 + NDM-1 (n = 7), KPC-2 (n = 1) or NDM-1 (n = 1) enzymes from one hospital from 2018, and sporadic isolates with KPC-2 (n = 1), NDM-1 (n = 1), VIM-1 (n = 1) or OXA-48 (n = 3), recovered from 2009 to 2019 in different towns. The isolates were sequenced by Illumina MiSeq, followed by MinION for six representatives. Clonality, phylogeny, serotypes, virulomes, resistomes and plasmids of the isolates were analysed and compared with international ST23 strains, using various bioinformatic tools. Only two diverse isolates with KPC-2 or VIM-1 were of typical hvKp ST23 serotypes K1 and O1v.2, and its predominant phylogenetic clade. These contained multiple chromosomal (ybt, clb) and pK2044/KpVP-1 plasmid (iuc, iro, rmpADC, rmpA2) virulence loci, whereas carbapenemase and other antimicrobial resistance (AMR) genes were on single additional plasmids. All remaining isolates were of K57 and O2v.2 serotypes, and a minor, distant clade of unclear phylogeny, including also ∼10 isolates from other European countries. These had fewer virulence loci (ybt, iuc, rmpADC, rmpA2) but abounded in plasmids, which with several chromosomal AMR mutations conferred more extensive MDR phenotypes than in K1 O1v.2. Lower clonal diversity than in K1, and numerous common characteristics of the isolates supported the hypothesis of the emerging character of the ST23 K57 clade. A new MDR ST23 lineage has emerged in Europe, causing a potential threat to public health.

To identify key factors of the expansion of metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa (MPPA) in Poland, focusing on the role of clonal epidemic(s). MPPA isolates were typed by PFGE, followed by MLST. bla_VIM/IMP MBL genes were amplified and sequenced within class 1 integrons. Their location was assessed by S1 nuclease-hybridization assays. Short-read WGS was performed, and genomes were subjected to SNP-based phylogenetic and resistome analyses. Of 1314 MPPA isolates collected in 2005–15 from 212 hospitals, 454 representatives were selected. The isolates belonged to 120 pulsotypes and 52 STs, of which ST235 (∼31%), ST111 (∼17%), ST273 (∼16%) and ST654 (∼9%) prevailed, followed by ST244, ST17, ST395, ST175 and ST1567. The isolates produced seven VIM variants (97.5%) and four IMPs encoded by 46 integrons, most of which were observed only or mainly in Poland. Around 60% of the isolates resulted from (inter)regional clonal outbreaks of 10 individual ST235, ST111, ST273 and ST654 genotypes. The phylogenetic analysis of 163 genomes revealed heterogeneity of ST235 and ST111 populations, arising from transnational circulation and on-site differentiation of several clades/branches. Contrarily, ST273 and ST654 formed relatively homogeneous and apparently Poland-specific lineages, and a unique ST273 genotype with integron In249 was the most expansive organism. Together with a previous report on self-transmissible In461-carrying IncP-2-type plasmids, this study revealed the molecular/genomic background of the rapid MPPA increase in Poland in 2001–15, evidencing multi-clonal spread as its leading factor. Numerous novel/specific MPPA characteristics were identified.

In 2003 to 2004, the first five VIM-2 metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa (MPPA) isolates with an In4-like integron, In461 ( aadB - bla _VIM-2 - aadA6 ), on conjugative plasmids were identified in three hospitals in Poland. In 2005 to 2015, MPPA expanded much in the country, and as many as 80 isolates in a collection of 454 MPPA (∼18%) had In461, one of the two most common MBL-encoding integrons.

Background: The war in Ukraine led to migration of Ukrainian people. Early 2022, several European national surveillance systems detected multidrug-resistant (MDR) bacteria related to Ukrainian patients. Aim: To investigate the genomic epidemiology of New Delhi metallo-β-lactamase (NDM)-producing Providencia stuartii from Ukrainian patients among European countries. Methods: Whole-genome sequencing of 66 isolates sampled in 2022–2023 in 10 European countries enabled whole-genome multilocus sequence typing (wgMLST), identification of resistance genes, replicons, and plasmid reconstructions. Five bla _NDM-1-carrying-P. stuartii isolates underwent antimicrobial susceptibility testing (AST). Transferability to Escherichia coli of a bla _NDM-1-carrying plasmid from a patient strain was assessed. Epidemiological characteristics of patients with NDM-producing P. stuartii were gathered by questionnaire. Results: wgMLST of the 66 isolates revealed two genetic clusters unrelated to Ukraine and three linked to Ukrainian patients. Of these three, two comprised bla _NDM-1-carrying-P. stuartii and the third bla _NDM-5-carrying-P. stuartii. The bla _NDM-1 clusters (PstCluster-001, n = 22 isolates; PstCluster-002, n = 8 isolates) comprised strains from seven and four countries, respectively. The bla _NDM-5 cluster (PstCluster-003) included 13 isolates from six countries. PstCluster-001 and PstCluster-002 isolates carried an MDR plasmid harbouring bla _NDM-1, bla _OXA-10, bla _CMY-16, rmtC and armA, which was transferrable in vitro and, for some Ukrainian patients, shared by other Enterobacterales. AST revealed PstCluster-001 isolates to be extensively drug-resistant (XDR), but susceptible to cefiderocol and aztreonam–avibactam. Patients with data on age (n = 41) were 19–74 years old; of 49 with information on sex, 38 were male. Conclusion: XDR P. stuartii were introduced into European countries, requiring increased awareness and precautions when treating patients from conflict-affected areas.

GES-type extended-spectrum β-lactamases (ESBLs), like GES-1, mutate by Gly170Asn/Ser substitutions into carbapenem-hydrolyzing variants, of which GES-5 is relatively more frequent (1, 2).…