Whole genome sequence analysis of ESBL-producing Escherichia coli recovered from New Zealand freshwater sites.

Extended-spectrum beta lactamase (ESBL)-producing are often isolated from humans with urinary tract infections and may display a multidrug-resistant phenotype. These pathogens represent a target for a One Health surveillance approach to investigate transmission between humans, animals and the environment. This study examines the multidrug-resistant phenotype and whole genome sequence data of four ESBL-producing . isolated from freshwater in New Zealand. All four isolates were obtained from a catchment with a mixed urban and pastoral farming land-use. Three isolates were sequence type (ST) 131 (CTX-M-27-positive) and the other ST69 (CTX-M-15-positive); a phylogenetic comparison with other locally isolated strains demonstrated a close relationship with New Zealand clinical isolates. Genes associated with resistance to antifolates, tetracyclines, aminoglycosides and macrolides were identified in all four isolates, together with fluoroquinolone resistance in two isolates. The ST69 isolate harboured the gene on a IncHI2A plasmid, and two of the three ST131 isolates harboured the genes on IncF plasmids. The last ST131 isolate harboured on the chromosome in a unique site between C and D. These data highlight a probable human origin of the isolates with subsequent transmission from urban centres through wastewater to the wider environment.