Decade of Carbapenemase-Producing Enterobacterales in New Caledonia: Integrative Surveillance Though Genomic, Phenotypic and Clinical approaches

Carbapenemase-producing Enterobacterales (CPE) have been identified by the World Health Organization as global priority pathogens. The dissemination of these bacteria and outbreaks within healthcare facilities are of serious concern. This study investigated the transmission patterns and genetic characteristics of CPE isolated in New Caledonia from 2013 to 2022. The isolates were identified and characterized both phenotypically and whole-genome sequencing (WGS). In total 214 CPE were isolated: 199 non duplicate clinical isolates from 164 patients and 15 from hospital environmental surface. The most common genera in clinical samples were Enterobacter (34%) and Klebsiella (25%), with 194 isolates (98%) carrying IMP-type carbapenemase. WGS of 89 isolates revealed the dominance of the bla _IMP-4 carbapenemase gene, found in 82 isolates. The bla _IMP-4 was primarily predicted to be carried by IncL/M-type plasmid, found in 69% of the sequenced isolates. Our work revealed the circulation of 12 bacterial clusters with 61 strains involved in outbreaks or persistent over time. Genomic, phenotypic and clinical approaches identified 12 distinct outbreaks involving IMP producers. These results highlight the importance of studying plasmid transmission to better prevent silent spread of CPE. Ultimately, this study provides new guidelines for limiting the clinical spread of CPE in New Caledonia.