A Framework for Standardized Monitoring of Antibiotic Resistance in Aquatic Environments and Application to Wastewater, Recycled Water, Surface Water, and Private Wells

Antimicrobial resistance (AMR) is a One-Health (human, animal, environment) challenge that requires collaborative, interdisciplinary action. Comparable surveillance data are needed to effectively inform policy interventions aimed at preventing the spread of AMR. Environmental monitoring lags behind that of other One Health sectors and is in need of agreed upon targets and standardized methods. A challenge is that there are numerous microorganisms, antibiotic resistance genes (ARGs), and mobile genetic elements and corresponding methods that have been proposed. In this dissertation, a framework for AMR monitoring of aquatic environments was developed through a combination of literature review and stakeholder input, via surveys and a workshop. Through this process, three targets were selected for standardization: the sulfonamide resistance gene (sul1), the class 1 integron integrase gene (intI1), and cefotaxime-resistant Escherichia coli. Quantitative polymerase chain reaction (qPCR)- and culture-based protocols were developed and pilot tested in two independent laboratories on a set of six water matrices: wastewater, recycled water, and surface water from six different wastewater utilities engaging in water reuse located in five states across the USA. The impact of wastewater treatment and advanced water treatment processes was examined in terms of removal of these targets. Finally, qPCR and culture methods were used to examine the relationship between sul1, intI1, E. coli, and fecal indicators in private household wells across four states in the Southern USA that were identified as susceptible to storm events. The overall findings provide a useful baseline occurrence of the proposed AMR monitoring indicators across a range of water types and protocols that are accessible to water utilities.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Civil Engineering

Department dc:contributor.department

Civil and Environmental Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Liguori, Krista Margaretta

Chair dc:contributor.committeechair

• Pruden, Amy

Committee members dc:contributor.committeemember

• Edwards, Marc A.
• Garner, Emily
• Krometis, Leigh-Anne H.

• antimicrobial resistance
• wastewater
• antibiotic resistance genes (ARGs)
• water quality

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:37554

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/115715