First Detection and Molecular Characterization of Pseudomonas aeruginosa bla NDM-1 ST308 in Greece.

The objective of the present study is to report the detection and the molecular characterization of nine bla NDM-1 -positive Pseudomonas aeruginosa isolates, all of which belonged to the epidemic high-risk international clone ST308, and all were isolated from patients in a tertiary care hospital in Central Greece from May to July 2023.The isolates were characterized by whole genome sequencing to obtain multi-locus sequencing typing (MLST) and identify the bla NDM1 -environment and resistome and virulence genes content. In silico MLST analysis showed that all isolates belonged to the high-risk ST308 international clone. All strains possessed 22 different genes, encoding resistance to various antimicrobial agents. Whole genome sequencing revealed that the bla NDM-1 was chromosomally located within the integrative and conjugative element ICE Tn 4371 6385 and that it was part of one cassette along with two other resistance genes, floR and msrE . Two additional resistance cassettes were also found in the genome, which included the arrays of aph(6)-Id , aph(3″)-Ib , floR , sul2 and aadA10 , qnrVC1 , aac(3)-Id , dfrB5 , aac(6')-II . Additionally, the strains possessed various virulence genes, e.g., aprA , exoU , lasA , lasB , toxA , and estA . All of the isolates shared identical genomes, which showed 98% similarity with the P. aeruginosa ST308 genome (acc. no CP020703), previously reported from Singapore. To our knowledge, this is the first report of ST308 bla NDM-1 -positive P. aeruginosa isolation in Europe, which indicates the transmission dynamics of this high-risk clone.