Abstract
A survey for antibiotic-resistant (AR) Escherichia coli in wastewater was undertaken by collecting samples from primary clarifiers and secondary effluents from seven geographically dispersed US wastewater treatment plants (WWTPs). Samples were collected at each WWTP in cool and summer months and cultured using selective media. The resulting isolates were characterized for resistance to imipenem, ciprofloxacin, cefotaxime, and ceftazidime, presence of carbapenemase and extended-spectrum beta-lactamase (ESBL) genes, and phylogroups and sequence types (STs). In total, 322 AR E. coli isolates were identified, of which 65 were imipenem-resistant. Of the 65 carbapenem-resistant E. coli (CREC) isolates, 62% were positive for more than one and 31% were positive for two or more of carbapenemase and ESBL genes targeted. The most commonly detected carbapenemase gene was blaVIM (n ¼ 36), followed by blaKPC (n ¼ 2). A widespread dispersal of carbapenem-resistant STs and other clinically significant AR STs observed in the present study suggested the plausible release of these strains into the environment. The occurrence of CREC in wastewater is a potential concern because this matrix may serve as a reservoir for gene exchange and thereby increase the risk of AR bacteria (including CR) being disseminated into the environment and thence back to humans.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 219-226 |
| Number of pages | 8 |
| Journal | Journal of Water and Health |
| Volume | 17 |
| Issue number | 2 |
| DOIs | |
| State | Published - Apr 1 2019 |
Bibliographical note
Funding Information:has been approved for external publication. This work was also supported in part by Office of Research and Development, Department of Veterans Affairs (VA). Any opinions expressed in this paper are those of the authors and do not necessarily reflect the views of the EPA or VA; therefore, no official endorsement should be inferred. Any mention of trade names or commercial products does not constitute endorsement or recommendation for use. All the positive control strains for qPCR testing were graciously provided by Drs Johann Pitout and Gisele Pierano from the University at Calgary Medical School, Calgary, Alberta, Canada. We would also like to thank Connie Clabots and Steph Porter for their technical assistance.
Funding Information:
The US Environmental Protection Agency (EPA), through its Office of Research and Development, funded and managed the research described herein. This work has been subjected to the agency’s administrative review and
Publisher Copyright:
© IWA Publishing 2019.
Keywords
- Carbapenem-resistant E. coli
- Carbapenemases
- ESBL
- Wastewater
