{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/132470"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/132470","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Shear force impacts type IV pilus and flagellar dynamics during Pseudomonas aeruginosa surface adhesion","abstract":"Surface-attached bacteria experience forces associated with fluid flow in nature. However, many studies on bacterial adhesion have been conducted in conditions either lacking flow or using forces not typically found in natural systems. In Chapter 2, I examine how Pseudomonas aeruginosa cells use type IV pili to interact with surfaces under host-relevant shear forces. I demonstrate that cell tilting, driven by type IV pilus retraction, predicts surface departure at low shear forces. Conversely, higher host-relevant shear forces counteract cell tilting and enhance adhesion. Thus, P. aeruginosa couples type IV pilus dynamics and cell geometry to tune adhesion to its mechanical environment. In Chapter 3, I investigate how host-relevant shear force impacts flagellar rotation during P. aeruginosa initial surface interactions. Experiments using strains having fluorescently-labeled flagella reveal that flow bends upstream-facing flagella and blocks rotation. Additionally, cells with upstream flagella exhibit fewer surface departures than cells with downstream flagella, showing that flagellar rotation drives surface departure. Therefore, these results reveal a novel role for flagellar rotation and determine how bacteria optimize surface interactions in dynamic environments. Together, these findings emphasize the need to study bacteria under mechanically relevant conditions. Shear force exerts a mechanical stress on surface attached bacterial cells, leading to prolonged surface adhesion. By integrating host-relevant conditions into bacterial research, my work has provided a clearer understanding of how P. aeruginosa optimizes surface behavior in dynamic environments.","abstract_html":"Surface-attached bacteria experience forces associated with fluid flow in nature. However, many studies on bacterial adhesion have been conducted in conditions either lacking flow or using forces not typically found in natural systems. In Chapter 2, I examine how Pseudomonas aeruginosa cells use type IV pili to interact with surfaces under host-relevant shear forces. I demonstrate that cell tilting, driven by type IV pilus retraction, predicts surface departure at low shear forces. Conversely, higher host-relevant shear forces counteract cell tilting and enhance adhesion. Thus, P. aeruginosa couples type IV pilus dynamics and cell geometry to tune adhesion to its mechanical environment. In Chapter 3, I investigate how host-relevant shear force impacts flagellar rotation during P. aeruginosa initial surface interactions. Experiments using strains having fluorescently-labeled flagella reveal that flow bends upstream-facing flagella and blocks rotation. Additionally, cells with upstream flagella exhibit fewer surface departures than cells with downstream flagella, showing that flagellar rotation drives surface departure. Therefore, these results reveal a novel role for flagellar rotation and determine how bacteria optimize surface interactions in dynamic environments. Together, these findings emphasize the need to study bacteria under mechanically relevant conditions. Shear force exerts a mechanical stress on surface attached bacterial cells, leading to prolonged surface adhesion. By integrating host-relevant conditions into bacterial research, my work has provided a clearer understanding of how P. aeruginosa optimizes surface behavior in dynamic environments.","abstract_has_math":false,"creators":["Palalay, Jessica-Jae S"],"institution":"University of Illinois Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Biochemistry","degree_department":null,"school":null,"contributors":["Sanfilippo, Joseph E","Huang, Raven H","Brieher, William M","Mera, Paola E"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-12","date_published":"2025-12","updated_at":"2026-07-22T22:25:07Z","subjects":["Microfluidics","shear force","adhesion","Pseudomonas aeruginosa","type IV pili","flagella"],"languages":["en"],"rights":["Copyright 2025 Jessica-Jae Palalay"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/132470","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Sanfilippo, Joseph E","Huang, Raven H","Brieher, William M","Mera, Paola E"]},{"key":"dc:creator","label":"Author","values":["Palalay, Jessica-Jae S"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-12","2025-10-14"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biochemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Microfluidics","shear force","adhesion","Pseudomonas aeruginosa","type IV pili","flagella"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2025 Jessica-Jae Palalay"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/132470"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Surface-attached bacteria experience forces associated with fluid flow in nature. However, many studies on bacterial adhesion have been conducted in conditions either lacking flow or using forces not typically found in natural systems. In Chapter 2, I examine how Pseudomonas aeruginosa cells use type IV pili to interact with surfaces under host-relevant shear forces. I demonstrate that cell tilting, driven by type IV pilus retraction, predicts surface departure at low shear forces. Conversely, higher host-relevant shear forces counteract cell tilting and enhance adhesion. Thus, P. aeruginosa couples type IV pilus dynamics and cell geometry to tune adhesion to its mechanical environment. In Chapter 3, I investigate how host-relevant shear force impacts flagellar rotation during P. aeruginosa initial surface interactions. Experiments using strains having fluorescently-labeled flagella reveal that flow bends upstream-facing flagella and blocks rotation. Additionally, cells with upstream flagella exhibit fewer surface departures than cells with downstream flagella, showing that flagellar rotation drives surface departure. Therefore, these results reveal a novel role for flagellar rotation and determine how bacteria optimize surface interactions in dynamic environments. Together, these findings emphasize the need to study bacteria under mechanically relevant conditions. Shear force exerts a mechanical stress on surface attached bacterial cells, leading to prolonged surface adhesion. By integrating host-relevant conditions into bacterial research, my work has provided a clearer understanding of how P. aeruginosa optimizes surface behavior in dynamic environments.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2026-02-19 without embargo terms","The student, Jessica-Jae Palalay, accepted the attached license on 2025-10-13 at 07:28.","The student, Jessica-Jae Palalay, submitted this Dissertation for approval on 2025-10-13 at 07:29.","This Dissertation was approved for publication on 2025-10-14 at 14:41.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22824 on 2026-02-19 at 18:24:20"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Shear force impacts type IV pilus and flagellar dynamics during Pseudomonas aeruginosa surface adhesion"]}]}],"canonical_facts":{"dc:contributor":["Sanfilippo, Joseph E","Huang, Raven H","Brieher, William M","Mera, Paola E"],"dc:creator":["Palalay, Jessica-Jae S"],"dc:date":["2025-12","2025-10-14"],"dc:description":["Surface-attached bacteria experience forces associated with fluid flow in nature. However, many studies on bacterial adhesion have been conducted in conditions either lacking flow or using forces not typically found in natural systems. In Chapter 2, I examine how Pseudomonas aeruginosa cells use type IV pili to interact with surfaces under host-relevant shear forces. I demonstrate that cell tilting, driven by type IV pilus retraction, predicts surface departure at low shear forces. Conversely, higher host-relevant shear forces counteract cell tilting and enhance adhesion. Thus, P. aeruginosa couples type IV pilus dynamics and cell geometry to tune adhesion to its mechanical environment. In Chapter 3, I investigate how host-relevant shear force impacts flagellar rotation during P. aeruginosa initial surface interactions. Experiments using strains having fluorescently-labeled flagella reveal that flow bends upstream-facing flagella and blocks rotation. Additionally, cells with upstream flagella exhibit fewer surface departures than cells with downstream flagella, showing that flagellar rotation drives surface departure. Therefore, these results reveal a novel role for flagellar rotation and determine how bacteria optimize surface interactions in dynamic environments. Together, these findings emphasize the need to study bacteria under mechanically relevant conditions. Shear force exerts a mechanical stress on surface attached bacterial cells, leading to prolonged surface adhesion. By integrating host-relevant conditions into bacterial research, my work has provided a clearer understanding of how P. aeruginosa optimizes surface behavior in dynamic environments.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2026-02-19 without embargo terms","The student, Jessica-Jae Palalay, accepted the attached license on 2025-10-13 at 07:28.","The student, Jessica-Jae Palalay, submitted this Dissertation for approval on 2025-10-13 at 07:29.","This Dissertation was approved for publication on 2025-10-14 at 14:41.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22824 on 2026-02-19 at 18:24:20"],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/132470"],"dc:language":["en"],"dc:rights":["Copyright 2025 Jessica-Jae Palalay"],"dc:subject":["Microfluidics","shear force","adhesion","Pseudomonas aeruginosa","type IV pili","flagella"],"dc:title":["Shear force impacts type IV pilus and flagellar dynamics during Pseudomonas aeruginosa surface adhesion"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Biochemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:07Z"}