Circulation of polyclonal OXA-244-producing Escherichia coli lineages in Jerusalem, Israel

Background and objectives OXA-244-producing Escherichia coli represents an emerging concern in Europe due to its rapid spread and difficult-to-detect phenotype. While other OXA-48-like carbapenemases emerged in Israel in 2007, the circulation of OXA-244-producing E. coli was only recently reported. We aimed to investigate the proportion of OXA-244 amongst OXA-48-like-producing E. coli in a tertiary care university hospital in Jerusalem, Israel, during 2024. We analysed their mode of acquisition, phylogeny, resistome, and the genetic context of blaOXA-244 in these isolates. Patients and methods In 2024, 171 patients were identified with OXA-48-like-producing E. coli from screening or clinical samples. Of these, 53 were selected using convenience sampling across the entire year for whole genome characterization using short-read sequencing and a subset also underwent long-read sequencing. Results Amongst the 53 sequenced OXA-48-like-producing E. coli, the majority harboured blaOXA-244 (n=34), followed by blaOXA-48 (n=11), and blaOXA-181 (n=8). Of the 34 OXA-244-producing E. coli, transmission was classified as probably or possibly healthcare-associated for 88.2%, and community-acquired for 11.8%. The OXA-244-producing E. coli isolates belonged to 13 distinct STs that mainly matched internationally described clones. Core genome MLST demonstrated seven genomic clusters (≤10 allele differences), indicating close common ancestry. Long-read sequencing demonstrated that blaOXA-244 was chromosomally located within variants of the transposon Tn51098 across STs. Conclusions This study demonstrates the predominance of OXA-244-producing E. coli in a tertiary care hospital in Jerusalem, Israel among OXA-48-like-producing isolates. The clonal diversity points to ongoing unrecognized community transmission, necessitating targeted surveillance and control measures.