---
title: "Curli's variable effects on biofilm formation and bovine-cell adherence in STEC O157, O26, O111"
id: "biorxiv-7-varied-influence-of-curli-on-shiga-toxin-producing-escherichia-coli-o157-o26"
canonical_url: "https://medichelpline.com/clinical-feed/biorxiv-7-varied-influence-of-curli-on-shiga-toxin-producing-escherichia-coli-o157-o26"
content_type: "clinical_feed_article"
specialty: "Infectious Disease"
source_name: "bioRxiv (Biomedical Preprints)"
source_url: "https://www.biorxiv.org/content/10.64898/2026.09.15.751941v1?rss=1"
published_at: "2026-09-20T12:00:00.000Z"
evidence_level: "Verified Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Curli's variable effects on biofilm formation and bovine-cell adherence in STEC O157, O26, O111
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/biorxiv-7-varied-influence-of-curli-on-shiga-toxin-producing-escherichia-coli-o157-o26
- **Specialty:** [Infectious Disease](https://medichelpline.com/clinical-feed/infectious-disease.md)
- **Primary Source:** bioRxiv (Biomedical Preprints)
- **Source URL:** [Original Journal Publication](https://www.biorxiv.org/content/10.64898/2026.09.15.751941v1?rss=1)
- **Published At:** 2026-09-20T12:00:00.000Z
- **Evidence Rating:** Verified Feed
## Executive GIST (TL;DR)
- This study evaluated 30 Shiga toxin-producing Escherichia coli (**STEC**) isolates from serotypes **O157, O26, and O111** for curli-associated phenotypes, environmental biofilm formation, and adherence to bovine recto-anal junction squamous epithelial (**RSE**) cells. - **O157** and **O111** isolates mostly showed strong aggregative adherence to RSE cells, while **O26** isolates displayed more heterogeneous and predominantly diffuse adherence patterns. - Under environmental growth conditions, **O111** isolates produced the strongest biofilms and tended to have more stable curli phenotypes; **O157** and **O26** isolates demonstrated greater variation in curli expression and biofilm strength. - Biofilm formation measured in environmental assays did not consistently predict adherence to bovine RSE cells; isolates with strong environmental biofilms were not uniformly strongly adherent. - When grown under host-simulated conditions (DMEM-LG) at 26°C, 37°C, and 39°C, biofilm formation was markedly reduced across isolates, including those that formed strong environmental biofilms. - Differences in Shiga toxin genotype or expression did not explain the principal adherence patterns; notably, some **O111** isolates lacking **stx2** still showed strong aggregative adherence. - Authors conclude that **curli-associated biofilm formation** is primarily driven by environmental conditions and does not directly predict STEC adherence to bovine epithelial cells; environmental persistence and host-cell attachment appear to be distinct phenotypes likely mediated by additional strain- and serotype-specific factors. - The data imply that control strategies for STEC in reservoirs like cattle should consider separate mechanisms for environmental survival versus epithelial colonization.
## Clinical Analysis & Structured Key Points
Varied influence of curli on Shiga toxin-producing Escherichia coli O157, O26, O111 biofilm formation and animal cell adherence. | bioRxiv Skip to main content New Results Varied influence of curli on Shiga toxin-producing Escherichia coli O157, O26, O111 biofilm formation and animal cell adherence. Indira T Kudva , Erika N. Biernbaum , Hannah Mazon , Koy Drabek doi: https://doi.org/10.64898/2026.09.15.751941 Indira T Kudva 1 USDA-ARS National Animal Disease Center; Find this author on Google Scholar Find this author on PubMed Search for this author on this site For correspondence: indira.kudva{at}usda.gov Erika N. Biernbaum 2 The Pennsylvania State University; Find this author on Google Scholar Find this author on PubMed Search for this author on this site Hannah Mazon 3 Tyson Foods (United States) Find this author on Google Scholar Find this author on PubMed Search for this author on this site Koy Drabek 2 The Pennsylvania State University; Find this author on Google Scholar Find this author on PubMed Search for this author on this site Abstract Info/History Metrics Preview PDF Abstract Shiga toxin-producing Escherichia coli (STEC) persist in cattle and can colonize the bovine recto-anal junction, making it an important reservoir for transmission. Curli are extracellular amyloid fibers associated with biofilm formation and environmental persistence, but their contribution to STEC adherence to bovine epithelial cells is unclear. This study examined the relationship between curli production, biofilm formation, and adherence of O157, O26, and O111 STEC isolates to bovine recto-anal junction (RAJ) squamous epithelial (RSE) cells. Thirty isolates were evaluated for RSE adherence, curli-associated phenotypes, and biofilm formation under environmental and host-associated growth conditions. O157 and O111 isolates predominantly exhibited strong aggregative adherence to RSE cells, whereas O26 isolates showed more heterogeneous, primarily diffuse adherence. O111 isolates produced the strongest biofilms under environmental conditions and displayed relatively stable curli phenotypes, while O157 and O26 isolates showed greater variation. However, environmental biofilm formation did not consistently correlate with RSE adherence. Biofilm formation was also markedly reduced under host-simulated conditions in DMEM-LG at 26, 37, and 39°C, including among isolates that produced strong environmental biofilms. Differences in Shiga toxin genotype and expression likewise did not account for the major adherence patterns, as O111 isolates lacking stx2 retained strong aggregative adherence. These findings indicate that curli-associated biofilm formation is primarily influenced by environmental conditions and does not directly predict STEC adherence to bovine RSE cells. The results suggest that environmental persistence and host-cell attachment represent distinct phenotypes and that STEC adherence to bovine epithelial cells is likely mediated by additional strain- and serotype-specific factors. Copyright The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. Back to top Previous Next Posted September 20, 2026. Download PDF Email Thank you for your interest in spreading the word about bioRxiv. NOTE: Your email address is requested solely to identify you as the sender of this article. Your Email * Your Name * Send To * Enter multiple addresses on separate lines or separate them with commas. You are going to email the following Varied influence of curli on Shiga toxin-producing Escherichia coli O157, O26, O111 biofilm formation and animal cell adherence. Message Subject (Your Name) has forwarded a page to you from bioRxiv Message Body (Your Name) thought you would like to see this page from the bioRxiv website. Your Personal Message CAPTCHA This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Share Varied influence of curli on Shiga toxin-producing Escherichia coli O157, O26, O111 biofilm formation and animal cell adherence. Indira T Kudva , Erika N. Biernbaum , Hannah Mazon , Koy Drabek bioRxiv 2026.09.15.751941; doi: https://doi.org/10.64898/2026.09.15.751941 Share This Article: Copy Citation Tools Varied influence of curli on Shiga toxin-producing Escherichia coli O157, O26, O111 biofilm formation and animal cell adherence. Indira T Kudva , Erika N. Biernbaum , Hannah Mazon , Koy Drabek bioRxiv 2026.09.15.751941; doi: https://doi.org/10.64898/2026.09.15.751941 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Tweet Widget Facebook Like Google Plus One Subject Areas All Articles Animal Behavior and Cognition (8013) Biochemistry (18739) Bioengineering (14888) Bioinformatics (44418) Biophysics (22599) Cancer Biology (19723) Cell Biology (26899) Clinical Trials (138) Developmental Biology (13965) Ecology (21005) Epidemiology (2067) Evolutionary Biology (25455) Genetics (16166) Genomics (23507) Immunology (18705) Microbiology (42503) Molecular Biology (18059) Neuroscience (93451) Paleontology (700) Pathology (2977) Pharmacology and Toxicology (5095) Physiology (8114) Plant Biology (15999) Scientific Communication and Education (2095) Synthetic Biology (4560) Systems Biology (10235) Zoology (2391)
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