{"id":{"repo_id":"uwo","oai_identifier":"oai:uwo.scholaris.ca:20.500.14721/32580"},"canonical_url":"https://search.dev.ndltd.org/etd/uwo/oai:uwo.scholaris.ca:20.500.14721/32580","repository":{"repo_id":"uwo","name":"Western University","base_url":"https://uwo.scholaris.ca/server/oai/request"},"display":{"title":"Herbicide Mediated Selection of Sulfonamide Resistant E. coli","abstract":"Asulam is an herbicide that is structurally analogous to sulfonamide antibiotics (sulfas), with the potential to contribute to the global antibiotic resistance crisis by cross-selecting for sulfa-resistant bacteria. To determine if asulam can select for antibiotic resistant bacteria, isothermal titration calorimetry (ITC) was used to assess the binding affinity of asulam with the target protein of sulfas, dihydropteroate synthase (DHPS). ITC confirmed asulam interacts with DHPS, and in vitro directed evolution experiments showed that prolonged asulam exposure can select for sulfa-insensitive DHPS in E. coli. Since mobile sul genes also encode for sulfa-insensitive DHPS, the potential effect of asulam on the dissemination of the sul genes in a simulated bacterial community was assessed. These data suggested that asulam can promote sulfa-resistance by increasing the frequency of chromosomal folP mutations, and/or acquisition of sul genes in E. coli, and uniquely induce deletions of multiple genes at concentrations exceeding environmental relevance.","abstract_html":"Asulam is an herbicide that is structurally analogous to sulfonamide antibiotics (sulfas), with the potential to contribute to the global antibiotic resistance crisis by cross-selecting for sulfa-resistant bacteria. To determine if asulam can select for antibiotic resistant bacteria, isothermal titration calorimetry (ITC) was used to assess the binding affinity of asulam with the target protein of sulfas, dihydropteroate synthase (DHPS). ITC confirmed asulam interacts with DHPS, and in vitro directed evolution experiments showed that prolonged asulam exposure can select for sulfa-insensitive DHPS in E. coli. Since mobile sul genes also encode for sulfa-insensitive DHPS, the potential effect of asulam on the dissemination of the sul genes in a simulated bacterial community was assessed. These data suggested that asulam can promote sulfa-resistance by increasing the frequency of chromosomal folP mutations, and/or acquisition of sul genes in E. coli, and uniquely induce deletions of multiple genes at concentrations exceeding environmental relevance.","abstract_has_math":false,"creators":["Muntz, Laura P"],"institution":"The University of Western Ontario","degree_name":"M Sc","degree_level":null,"degree_discipline":"Microbiology and Immunology","degree_department":null,"school":null,"contributors":[],"advisors":["Michael J Fruci","Martin J McGavin"],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-10-21","date_published":"2022-10-21","updated_at":"2026-07-27T21:56:07Z","subjects":["Antibiotic resistance","E. coli","One Health","Asulam","herbicides","Sulfonamides"],"languages":["en_ca"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/20.500.14721/32580","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Michael J Fruci","Martin J McGavin"]},{"key":"dc:creator","label":"Author","values":["Muntz, Laura P"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-07-10T19:32:35Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-07-10T19:32:35Z"]},{"key":"dc:date.issued","label":"Date","values":["2022-10-21"]},{"key":"dc:publisher","label":"Institution","values":["The University of Western Ontario"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Microbiology and Immunology"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M Sc"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Antibiotic resistance","E. coli","One Health","Asulam","herbicides","Sulfonamides"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_ca"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/20.500.14721/32580"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."]},{"key":"dc:description.abstract","label":"Abstract","values":["Asulam is an herbicide that is structurally analogous to sulfonamide antibiotics (sulfas), with the potential to contribute to the global antibiotic resistance crisis by cross-selecting for sulfa-resistant bacteria. To determine if asulam can select for antibiotic resistant bacteria, isothermal titration calorimetry (ITC) was used to assess the binding affinity of asulam with the target protein of sulfas, dihydropteroate synthase (DHPS). ITC confirmed asulam interacts with DHPS, and in vitro directed evolution experiments showed that prolonged asulam exposure can select for sulfa-insensitive DHPS in E. coli. Since mobile sul genes also encode for sulfa-insensitive DHPS, the potential effect of asulam on the dissemination of the sul genes in a simulated bacterial community was assessed. These data suggested that asulam can promote sulfa-resistance by increasing the frequency of chromosomal folP mutations, and/or acquisition of sul genes in E. coli, and uniquely induce deletions of multiple genes at concentrations exceeding environmental relevance."]},{"key":"dc:title","label":"Title","values":["Herbicide Mediated Selection of Sulfonamide Resistant E. coli"]}]}],"canonical_facts":{"dc:contributor.advisor":["Michael J Fruci","Martin J McGavin"],"dc:creator":["Muntz, Laura P"],"dc:date.accessioned":["2025-07-10T19:32:35Z"],"dc:date.available":["2025-07-10T19:32:35Z"],"dc:date.issued":["2022-10-21"],"dc:description":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."],"dc:description.abstract":["Asulam is an herbicide that is structurally analogous to sulfonamide antibiotics (sulfas), with the potential to contribute to the global antibiotic resistance crisis by cross-selecting for sulfa-resistant bacteria. To determine if asulam can select for antibiotic resistant bacteria, isothermal titration calorimetry (ITC) was used to assess the binding affinity of asulam with the target protein of sulfas, dihydropteroate synthase (DHPS). ITC confirmed asulam interacts with DHPS, and in vitro directed evolution experiments showed that prolonged asulam exposure can select for sulfa-insensitive DHPS in E. coli. Since mobile sul genes also encode for sulfa-insensitive DHPS, the potential effect of asulam on the dissemination of the sul genes in a simulated bacterial community was assessed. These data suggested that asulam can promote sulfa-resistance by increasing the frequency of chromosomal folP mutations, and/or acquisition of sul genes in E. coli, and uniquely induce deletions of multiple genes at concentrations exceeding environmental relevance."],"dc:identifier.uri":["https://hdl.handle.net/20.500.14721/32580"],"dc:language.iso":["en_ca"],"dc:publisher":["The University of Western Ontario"],"dc:subject":["Antibiotic resistance","E. coli","One Health","Asulam","herbicides","Sulfonamides"],"dc:title":["Herbicide Mediated Selection of Sulfonamide Resistant E. coli"],"dc:type":["thesis"],"thesis:degree_discipline":["Microbiology and Immunology"],"thesis:degree_name":["M Sc"]},"updated_at":"2026-07-27T21:56:07Z"}