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Journal of Environmental and Public Health
Volume 2019, Article ID 3862949, 13 pages
Research Article

Antimicrobial-Resistant Escherichia coli from Environmental Waters in Northern Colorado

1Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
2Graduate Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
3Department of Medical Biochemistry, Faculty of Medicine, University of Zagazig, Zagazig 44519, Egypt
4Drake Water Reclamation Facility, Fort Collins, CO 80525, USA
5Department of Microbiology and Parasitology, Universidad Nacional Autónoma de Nicaragua, León, Nicaragua
6Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA

Correspondence should be addressed to Elizabeth P. Ryan; ude.etatsoloc@nayr.p.e

Hannah B. Haberecht and Nora Jean Nealon contributed equally to this work.

Received 11 October 2018; Accepted 13 January 2019; Published 18 February 2019

Academic Editor: Chunrong Jia

Copyright © 2019 Hannah B. Haberecht et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Waterborne Escherichia coli are a major reservoir of antimicrobial resistance (AMR), including but not limited to extended-spectrum beta-lactamase (ESBL) and Klebsiella pneumoniae carbapenemase (KPC) mechanisms. This study quantified and described ESBL- and KPC-producing E. coli in Northern Colorado from sewer water, surface water, and influent and effluent wastewater treatment sources. Total detected bacteria and E. coli abundances, and the percentages that contain ESBL and/or KPC, were compared between water sources. Seventy E. coli isolates from the various waters had drug resistance validated with a panel of 17 antibiotics using a broth microdilution assay. The diverse drug resistance observed across E. coli isolates was further documented by polymerase chain reaction of common ESBL genes and functional relatedness by PhenePlate assay-generated dendrograms (). The total E. coli abundance decreased through the water treatment process as expected, yet the percentages of E. coli harboring ESBL resistance were increased (1.70%) in surface water. Whole-genome sequencing analysis was completed for 185 AMR genes in wastewater E. coli isolates and confirmed the presence of diverse AMR gene classes (e.g., beta-lactams and efflux pumps) in isolate genomes. This study completed surveillance of AMR patterns in E. coli that reside in environmental water systems and suggests a role for integrating both phenotypic and genotypic profiling beyond ESBL and KPC mechanisms. AMR screening via multiple approaches may assist in the prevention of drug-resistant E. coli spread from waters to animals and humans.