Key points are not available for this paper at this time.
Introduction: Antimicrobial resistance (AMR) is a growing global concern. Clonal lineages of CTX-M β-lactamase-producing Escherichia coli (CTXE) and quinolone-resistant E. coli (QREC) were disseminated among deer population in a famous tourist destination (Nara Park; NP) in Japan. Hypothesis or Gap statement: The molecular characteristics of CTXE or QREC isolates which could threat public health has not been elucidated. Aim: This study aimed to characterize the genetic traits of CTXE and QREC isolates derived from NP deer and compare them with lineages prevalent worldwide. Methodology: Sixteen CTXE and three QREC isolates recovered from NP deer feces between 2018 and 2020 were analyzed using whole-genome sequencing. For endemic lineages, phylogenetic trees were constructed using the core genome single nucleotide polymorphism scheme. Results: Several pandemic lineages, such as ST38, ST58, and ST117, were included. The QREC lineages prevalent among deer were designated as extra-intestinal pathogenic E. coli or uropathogenic E. coli. Thirteen of the 24 ARG were considered high-risk ARG families. Chromosomal integration of blaCTX-M-15 was observed in all plasmid-negative isolates. Phylogenetic analysis showed relationship between ST3580 O8:H12 isolates obtained in NP and neighboring area. Conclusion: Our study provides the evidence that multiple clinically important lineages of CTXE and QREC are endemic in NP deer and they could have public health impact. Further studies are required to investigate the relationship between chromosomal integration of plasmid-encoded genes and the stable propagation of AMR bacteria in wildlife and the environment.
Ikushima et al. (Wed,) studied this question.