Screening for carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in freshwater, bathing water, and hospital continuum in Belgium

Abstract

ObjectiveThis study focused on carbapenemase-producing (CP) Escherichia coli and Klebsiella pneumoniae in the aquatic environment in Belgium, based on the screening of three hospital continuums (hospital-wastewater treatment plant-receiving river), 20 surface waters and 29 bathing waters in 2022.MethodsThe strains were enumerated and isolated from CHROMagar SuperCARBA medium. Phenotypic tests including disk combination tests to identify the Ambler class, genotypic tests (real-time PCR) and immunochromatographic tests were used to characterize each isolate and determine the carbapenemase produced (blaNDM, blaKPC, blaOXA-48, blaVIM, blaIMP). The genomes of 11 CP E. coli and 14 CP K. pneumoniae were sequenced.ResultsNo CP E. coli nor CP K. pneumoniae were isolated from bathing waters, while 24 CP E. coli and 22 CP K. pneumoniae were isolated from six of the 20 surface water samples and from hospital continuums. Of the 24 CP E. coli strains, 20 had the blaKPC gene (83.3%) and four the blaOXA gene (16.6%), whereas of the 22 CP K. pneumoniae strains, the number of strains with carbapenemase genes was: 11 blaKPC (50.0%), nine blaOXA (40.9%), one blaVIM (4.5%), and one blaNDM (4.5%). The genomes of 11 CP E. coli and 14 CP K. pneumoniae were sequenced, and all possessed carbapenemase genes - blaKPC-3 (n = 12), blaOXA-48 (n = 10), blaOXA-244 (n = 1), blaVIM-1 (n = 1), and blaNDM-5 (n = 1) - mostly coupled to ESBL-encoding genes.ConclusionsThis study demonstrates that CP E. coli and CP K. pneumoniae are disseminated in the Belgian aquatic environment and suggests the role of hospital effluents in this dissemination.