Novel IncM1 plasmid harbouring blaKPC-2 disseminating in Klebsiella pneumoniae and Enterobacter hormaechei within a patient

C. A. KNECHT; D. CENTRÓN; A. S. GAMBINO; A. C. LEGUINA

Congreso; International Union of Microbiological Societies (IUMS); 2022

International Union of Microbiological Societies (IUMS)

Background and AimsAccording to the World Health Organization, carbapenem resistant Enterobacterales (CRE) bacteria belong tothe highest priority group. WHONET data from Argentina showed that Gram-negative resistance levels toimipenem have been increasing since 2010 mostly in two CRE species: Klebsiella pneumoniae andEnterobacter cloacae Complex. Our aim was to analyze the blaKPC-2 genetic platform of two strains belongingto these species colonizing a patient during hospitalization.MethodsWe isolated two CRE strains from one patient in a hospital from Argentina and sequenced their whole genomeby Illumina MiSeq-I. The genome was assembled with SPAdes 3.9.0, and annotated with PROKKA, RAST andBlastn. Plasmids were identified with PlasmidFinder. Antibiotic resistance genes were detected usingRESfinder, CARD and Blastn. Sequence types (ST) were identified with pubMLST. In vitro competition assaywas done.ResultsThe first isolated strain was a Klebsiella pneumoniae strain which belonged to ST18. The second one was anEnterobacter hormaechei strain that belonged to the pandemic lineage ST45. Both strains were multidrugresistant and carried the same conjugative IncM1 plasmid (77.2 Kb) with blaKPC-2 embedded in the geneticelement ISKpn27-blaKPC-2-ISKpn6-HP-Tn3, previously detected in IncP and R plasmids. In vitro competitiondid not show a clear advantage of a strain over the other nor over K. pneumoniae ST258. Secretion system IVpresent in Enterobacter and not in Klebsiella could account for prevalence of the latter in the patient.ConclusionsThis study describes a novel plasmid and further confirms that blaKPC-2 is highly mobilizable and prone tohorizontal genetic transfer events between species of Enterobacteriaceae