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Objectives: NDM-producing Enterobacteriaceae clinical isolates remain uncommon in the European region. We describe the emergence and broad dissemination of one successful NDM-1-producing Klebsiella pneumoniae clone in Greek hospitals.Methods: During a 4 year survey (January 2013-December 2016), 480 single-patient carbapenem non-susceptible K. pneumoniae isolates, phenotypically MBL positive, were consecutively recovered in eight Greek hospitals from different locations and subjected to further investigation. Antimicrobial susceptibility testing, combined-disc test, identification of resistance genes by PCR and sequencing, molecular fingerprinting by PFGE, plasmid profiling, replicon typing, conjugation experiments and MLST were performed.Results: Molecular analysis confirmed the presence of the blaNDM-1 gene in 341 (71%) K. pneumoniae isolates. A substantially increasing trend of NDM-1-producing K. pneumoniae was noticed during the survey (R2 = 0.9724). Most blaNDM-1-carrying isolates contained blaCTX-M-15, blaOXA-1, blaOXA-2 and blaTEM-1 genes. PFGE analysis clustered NDM-1 producers into five distinct clonal types, with five distinct STs related to each PFGE clone. The predominant ST11 PFGE clonal type was detected in all eight participating hospitals, despite adherence to the national infection control programme; it was identical to that observed in the original NDM-1 outbreak in Greece in 2011, as well as in a less-extensive NDM-1 outbreak in Bulgaria in 2015. The remaining four ST clonal types (ST15, ST70, ST258 and ST1883) were sporadically detected. blaNDM-1 was located in IncFII-type plasmids in all five clonal types.Conclusions: This study gives evidence of possibly the largest NDM-1-producing K. pneumoniae outbreak in Europe; it may also reinforce the hypothesis of an NDM-1 clone circulating in the Balkans. [ABSTRACT FROM AUTHOR]

Objectives: To discover the Escherichia coli STs and associated resistance mechanisms in the community in Islamabad, Pakistan by analysis of E. coli isolates in sewage.Methods: One hundred and ten E. coli were isolated from sewage across the city of Islamabad without antibiotic bias and confirmed as E. coli by MALDI-TOF MS. Isolates were characterized by fumC/fimH (CH) typing and core-genome MLST. Resistance mechanisms, virulence genes, phylotypes and plasmid incompatibility types were determined in a subset of isolates by in silico analysis. The genomic position of blaCTX-M-15 was determined using S1-PFGE, probing and Nanopore MinION sequencing.Results and conclusions: The most prevalent STs were ST394, ST10 and ST648, accounting for 39% of all isolates collected and were found at many sites across Islamabad. Carbapenemase genes were absent and only a single isolate of ST131 was found. The most prevalent resistance mechanisms were qnrS1 and blaCTX-M-15, with blaCTX-M-15 penetrating many STs and found in 31% of all collected isolates. However, the majority of the successful STs were blaCTX-M-15 negative indicating that resistance is not the main driver of prevalence. Twenty-three percent of blaCTX-M-15 genes were chromosomally encoded and large ISEcp1-mediated insertions included qnrS1 and several plasmid genes. In all chromosomally encoded isolates no plasmid copies of blaCTX-M-15 were found. The most prevalent ST (ST394) contained many enteroaggregative E. coli virulence genes and the fimH30 variant allele previously linked to the success of ST131. [ABSTRACT FROM AUTHOR]

Phylogeographical research has revealed several paradigm patterns of postglacial range expansion from the Mediterranean peninsulas to more northern parts of Europe. These range expansions have consequences for the genetic constitution of populations. Although many studies have been performed in mainland Europe, the colonization history of the British Isles is relatively poorly studied; the genetic consequences of the last glacial readvances and the climate optimum conditions, as well as the implications of the recent climatic conditions on the population genetic structures, are little understood. Therefore, we selected the common blue butterfly Polyommatus icarus as a model species for understanding more generally the colonization patterns of the British Isles and the genetic dynamics on these islands. Allozyme analyses of this butterfly show a rather high genetic diversity over continental Europe without major genetic differentiation. The situation on the British Isles is completely different. Here, populations show a much lower genetic diversity compared to mainland Europe. The genetic constitution is well differentiated from that observed on the European mainland, and the genetic differentiation among populations in Britain is stronger than at the European scale. These results support the hypothesis that a relatively cold-tolerant species such as the common blue could have colonized the British Isles early during the late glacial period and survived the last glacial readvances in small refugia in the South. The retraction of this species in small isolated populations could have caused the genetic impoverishment found. The subsequent forest climax during the climate optimum possibly restricted further expansion of this early succession species to small pockets all over the British Isles, resulting in the genetic patchwork that is still observed. Additionally, the relatively cool and rainy conditions one these islands might have caused bottlenecks, possibly enforcing these genetic patterns. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ••, ••-••. [ABSTRACT FROM AUTHOR]