Oxacillinase-484-Producing Enterobacterales, France, 2018-2023

Abstract

We examined the emergence and characteristics of oxacillinase-484-producing Enterobacterales in France during 2012-2023. Genomic analysis identified 2 predominant sequence types in Escherichia coli: ST410 and ST1722. Plasmid analysis revealed that bla_OXA-484 genes were carried mostly on an IncX3-type plasmid associated with genetic elements including insertion sequences IS3000 and ISKpn19.

Keywords: Antimicrobial resistance; E. coli ST1722; E. coli ST410; Enterobacterales; Escherichia coli; France; OXA-484; bacteria; carbapenemase; epidemiology; oxacillinase.

Figure 1

Evolution of number of OXA-484–producing CPE isolates received at the French National Reference Center for Carbapenem-Resistant Enterobacterales, France, 2012–2023. No OXA-484–producing isolate was received before 2018. Colors indicate species and STs. CPE, carbapenem-resistant Enterobacterales; OXA, oxacillinase; ST, sequence type.

Figure 2

Phylogenetic tree and location of carbapenem-resistant Escherichia coli sequence type (ST) 410 isolates received at the French National Reference Center for Carbapenem-Resistant Enterobacterales, France, 2012–2023. Carbapenemases are classified into 3 of the 4 Ambler classes: class A (mainly Klebsiella pneumoniae carbapenemase); class B or metallo-β-lactamases (predominantly NDM, VIM, or imipenemase types); and class D, primarily OXA-48–like types, including OXA-484 producers. Carbapenemase types are detailed and OXA-484 producers are indicated. ST410 strains are distinguished by whether there are amino acid insertions (YRIK, YRIN, YRIP, or YTIP motifs) in PBP3. We conducted the single-nucleotide polymorphism analysis on a common genome representing 89.05% of the entire genome of the reference strain 303D1. Map shows locations where specific mechanisms were found. ESBL, extended-spectrum β-lactamase; Hcase, helicase; NDM, New Delhi metallo-β-lactamase; OXA, oxacillinase; PBP3, penicillin-binding protein 3; VIM, Verona integron-encoded metallo-β-lactamase.

Figure 3

Genetic environments of bla_OXA-484 genes for 64 strains included in a study of oxacillinase-484–producing isolates received at the French National Reference Center for Carbapenem-Resistant Enterobacterales, France, 2012–2023. A) All strains; B) strain 346D9; C) strains 173G7 and 172D10. The bla_OXA-484 genes are shown in red, mobile elements are in yellow, and other genes in gray. The sequence homologies represented in light blue show an identity of >99.95%.