Endemicity of Producing IMP-18 And/or VIM-2 MBLs from the High-risk Clone ST111 in Central America

Background: is an important cause of serious nosocomial infections. Despite the overall genetic diversity of this species, highly conserved clonal complexes (CCs) have been observed among MDR isolates. Many of these CCs are associated with MBL-producing isolates.

Objectives: To evaluate five isolates from Central America that carried IMP-18- and/or VIM-2-encoding genes from the SENTRY Antimicrobial Surveillance Program (2017-2018).

Methods: Susceptibility testing was performed by broth microdilution (CLSI). WGS was performed using MiSeq (Illumina) and MinION (Oxford Nanopore). Assembled contigs from short and long reads were combined for screening of resistance genes, MLST, core genome (cg)MLST and SNP analysis.

Results: The isolates were collected in Panama and Mexico from patients with urinary tract infections or pneumonia. Isolates were categorized as XDR (CLSI/EUCAST). All isolates belonged to ST111 but carried different combinations of resistance-encoding genes. Transposon-associated MBL genes, and/or , were chromosomally located. was detected in an In integron whereas was embedded in an In-like integron. Isolates were closely related based on cgMLST (average allele distance 2-34) and SNP analysis (5-423 different SNPs).

Conclusions: MBL-producing ST111 have become endemic in Panama and may have spread to Mexico via clonal dissemination. Recombination events are apparent in the evolution of this CC. Surveillance is warranted to track the expansion and movement of this clone.